NIST Special Publication 1148-4 

Benefits and Costs of Energy 

Standard Adoption in New 

Commercial Buildings: West 

Census Region 

Joshua Kneifel 

http://dx.doi.org/10.6028/NIST.SP.1148-4 

 

 

 

 

 

 

 

 

 

 

 

 

 

NIST Special Publication 1148-4 

Benefits and Costs of Energy 

Standard Adoption in New 

Commercial Buildings: West 

Census Region 

Joshua Kneifel 

Applied Economics Office 

Engineering Laboratory 

http://dx.doi.org/10.6028/NIST.SP.1148-4 

February 2013 

U.S. Department of Commerce 

Rebecca Blank, Acting Secretary 

National Institute of Standards and Technology 

Patrick D. Gallagher, Under Secretary of Commerce for Standards and Technology and Director 
 

 

 

 

 

 

 

Certain commercial entities, equipment, or materials may be identified in this 

document in order to describe an experimental procedure or concept adequately. 

Such identification is not intended to imply recommendation or endorsement by the 

National Institute of Standards and Technology, nor is it intended to imply that the 

entities, materials, or equipment are necessarily the best available for the purpose. 

National Institute of Standards and Technology Special Publication 1148-4
 

Natl. Inst. Stand. Technol. Spec. Publ. 1148-4, 213 pages (February 2013)
 

http://dx.doi.org/10.6028/NIST.SP.1148-4
 

CODEN: NSPUE2
 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Abstract 

Energy efficiency requirements in energy codes for commercial buildings vary across 

states, and many states have not yet adopted the latest energy efficiency standard edition. 

As of December 2011, states had adopted energy codes ranging across editions of 

American Society of Heating, Refrigerating and Air-Conditioning Engineers Energy 

Standard for Buildings Except Low-Rise Residential Buildings (ASHRAE) 90.1 

(-2001, -2004, and -2007). Some states do not have a code requirement for energy 

efficiency, leaving it up to the locality or jurisdiction to set its own requirements. This 

study considers the impacts that the adoption of newer, more stringent energy codes for 

commercial buildings would have on building energy use, operational energy costs, 

building life-cycle costs, and cradle-to-grave energy-related carbon emissions. 

The results of this report are based on analysis of the Building Industry Reporting and 

Design for Sustainability (BIRDS) database, which includes 12 540 whole building 

energy simulations covering eleven building types in 228 cities across all U.S. states for 

nine study period lengths. The performance of buildings designed to meet current state 

energy codes is compared to their performance when meeting alternative building energy 

standard editions to determine whether more stringent energy standard editions are 

cost-effective in reducing energy consumption and energy-related carbon emissions. Each 

state energy code is also compared to a “Low Energy Case” (LEC) building design that 

increases energy efficiency beyond the ASHRAE 90.1-2007 design. The estimated 

savings for each of the building types are aggregated using new commercial building 

construction data to calculate the magnitude of the available savings that each state in the 

West Census Region may realize if it were to adopt a more energy efficient standard as 

its state energy code. 

Keywords 

Building economics; economic analysis; life-cycle costing; life-cycle assessment; energy 

efficiency; commercial buildings 

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Preface 

This study was conducted by the Applied Economics Office in the Engineering 

Laboratory (EL) at the National Institute of Standards and Technology (NIST). The 

study is designed to assess the energy consumption, life-cycle cost, and energy-related 

carbon emissions impacts from the adoption of new state energy codes based on more 

stringent building energy standard editions. The intended audience is researchers and 

policy makers in the commercial building sector, and others interested in building energy 

efficiency. 

Disclaimer 

The policy of the National Institute of Standards and Technology is to use metric units in 

all of its published materials. Because this report is intended for the U.S. construction 

industry that uses U.S. customary units, it is more practical and less confusing to include 

U.S. customary units as well as metric units. Measurement values in this report are 

therefore stated in metric units first, followed by the corresponding values in U.S. 

customary units within parentheses. 

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Acknowledgements 

The author wishes to thank all those who contributed ideas and suggestions for this 

report. They include Ms. Barbara Lippiatt and Dr. Robert Chapman of EL’s Applied 

Economics Office, Dr. Andrew Persily of EL’s Energy and Environment Division, and 

Dr. Nicos S. Martys of EL’s Materials and Structural Systems Division. A special thanks 

to Mr. Nicholas Long and the EnergyPlus Team for generating the initial energy 

simulations for this project. Thanks to Mr. Brian Presser for adapting the energy 

simulations to meet the study requirements and generating the final simulations used in 

the database. Thanks to Mr. Nathaniel Soares for developing the initial version of the 

Building Industry Reporting and Design for Sustainability (BIRDS) database, and to Ms. 

Priya Lavappa for enhancing the database for the current analysis. The author would like 

to thank the NIST Engineering Laboratory for its support of the project. 

Author Information 

Joshua D. Kneifel 

Economist 

National Institute of Standards and Technology 

Engineering Laboratory 

100 Bureau Drive, Mailstop 8603 

Gaithersburg, MD 20899-8603 

Tel.: 301-975-6857 

Email: joshua.kneifel@nist.gov 

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Table of Contents
 

Abstract.............................................................................................................................. ii
 

List of Acronyms .......................................................................................................... xxiv
 

Executive Summary ..................................................................................................... xxvi
 

Preface............................................................................................................................... iv
 

Acknowledgements .......................................................................................................... vi
 

Author Information ......................................................................................................... vi
 

List of Figures................................................................................................................. xiv
 

List of Tables .................................................................................................................. xvi
 

1 Introduction ............................................................................................................... 1
 

1.1 Background and Purpose...................................................................................... 1
 

1.2 Literature Review ................................................................................................. 1
 

1.3 Approach .............................................................................................................. 3
 

2 Study Design .............................................................................................................. 5
 

2.1 Building Types ..................................................................................................... 5
 

2.2 Building Designs .................................................................................................. 6
 

2.3 Study Period Lengths ........................................................................................... 8
 

3 Cost Data.................................................................................................................... 9
 

3.1 First Costs............................................................................................................. 9
 

3.2 Future Costs........................................................................................................ 12
 

4 Building Stock Data ................................................................................................ 15
 

4.1 Databases............................................................................................................ 15
 

4.2 Weighting Factors .............................................................................................. 15
 

5 Analysis Approach .................................................................................................. 17
 

5.1 Energy Use ......................................................................................................... 17
 

5.2 Life-Cycle Costing ............................................................................................. 17
 

5.3 Carbon Assessment ............................................................................................ 18
 

5.4 Analysis Metrics................................................................................................. 19
 

6 Alaska....................................................................................................................... 21
 

6.1 Percentage Savings............................................................................................. 21
 

6.1.1 Energy Use ................................................................................................ 22
 

6.1.2 Energy Costs ............................................................................................. 23
 

6.1.3 Energy-related Carbon Emissions............................................................. 24
 

6.1.4 Life-Cycle Costs ....................................................................................... 24
 

6.1.5 City Comparisons...................................................................................... 25
 

6.2 Total Savings...................................................................................................... 28
 

6.2.1 Energy Use ................................................................................................ 28
 

6.2.2 Energy Costs ............................................................................................. 30
 

6.2.3 Energy-related Carbon Emissions............................................................. 31
 

6.2.4 Life-Cycle Costs ....................................................................................... 33
 

6.3 State Summary ................................................................................................... 34
 

7 Arizona ..................................................................................................................... 37
 

7.1 Percentage Savings............................................................................................. 38
 

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7.1.1 Energy Use ................................................................................................ 38
 

7.1.2 Energy Costs ............................................................................................. 39
 

7.1.3 Energy-related Carbon Emissions............................................................. 40
 

7.1.4 Life-Cycle Costs ....................................................................................... 41
 

7.1.5 City Comparisons...................................................................................... 41
 

7.2 Total Savings...................................................................................................... 44
 

7.2.1 Energy Use ................................................................................................ 44
 

7.2.2 Energy Costs ............................................................................................. 46
 

7.2.3 Energy-related Carbon Emissions............................................................. 47
 

7.2.4 Life-Cycle Costs ....................................................................................... 49
 

7.3 State Summary ................................................................................................... 50
 

8 California ................................................................................................................. 53
 

8.1 Percentage Savings............................................................................................. 53
 

8.1.1 Statewide Building Comparison ............................................................... 54
 

8.1.2 City Comparisons...................................................................................... 55
 

8.2 Total Savings...................................................................................................... 56
 

8.2.1 Energy Use ................................................................................................ 57
 

8.2.2 Energy Costs ............................................................................................. 58
 

8.2.3 Energy-related Carbon Emissions............................................................. 60
 

8.2.4 Life-Cycle Costs ....................................................................................... 61
 

8.3 State Summary ................................................................................................... 62
 

9 Colorado................................................................................................................... 63
 

9.1 Percentage Savings............................................................................................. 63
 

9.1.1 Energy Use ................................................................................................ 64
 

9.1.2 Energy Costs ............................................................................................. 65
 

9.1.3 Energy-related Carbon Emissions............................................................. 65
 

9.1.4 Life-Cycle Costs ....................................................................................... 66
 

9.1.5 City Comparisons...................................................................................... 67
 

9.2 Total Savings...................................................................................................... 69
 

9.2.1 Energy Use ................................................................................................ 70
 

9.2.2 Energy Costs ............................................................................................. 72
 

9.2.3 Energy-related Carbon Emissions............................................................. 73
 

9.2.4 Life-Cycle Costs ....................................................................................... 74
 

9.3 State Summary ................................................................................................... 76
 

10 Hawaii ...................................................................................................................... 79
 

10.1 Percentage Savings............................................................................................. 79
 

10.1.1 Energy Use .......................................................................................... 80
 

10.1.2 Energy Costs ........................................................................................ 80
 

10.1.3 Energy-related Carbon Emissions Reduction...................................... 81
 

10.1.4 Life-Cycle Costs .................................................................................. 82
 

10.1.5 City Comparisons ................................................................................ 83
 

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10.2 Total Savings...................................................................................................... 84
 

10.2.1 Energy Use .......................................................................................... 84
 

10.2.2 Energy Costs ........................................................................................ 86
 

10.2.3 Energy-related Carbon Emissions ....................................................... 87
 

10.2.4 Life-Cycle Costs .................................................................................. 89
 

10.3 State Summary ................................................................................................... 90
 

11 Idaho......................................................................................................................... 91
 

11.1 Percentage Savings............................................................................................. 91
 

11.1.1 Statewide Building Comparison .......................................................... 91
 

11.1.2 City Comparisons ................................................................................ 93
 

11.2 Total Savings...................................................................................................... 94
 

11.2.1 Energy Use .......................................................................................... 94
 

11.2.2 Energy Costs ........................................................................................ 96
 

11.2.3 Energy-related Carbon Emissions ....................................................... 97
 

11.2.4 Life-Cycle Costs .................................................................................. 98
 

11.3 State Summary ................................................................................................. 100
 

12 Montana ................................................................................................................. 101
 

12.1 Percentage Savings........................................................................................... 101
 

12.1.1 Statewide Building Comparison ........................................................ 101
 

12.1.2 City Comparisons .............................................................................. 103
 

12.2 Total Savings.................................................................................................... 104
 

12.2.1 Energy Use ........................................................................................ 104
 

12.2.2 Energy Costs ...................................................................................... 105
 

12.2.3 Energy-related Carbon Emissions ..................................................... 107
 

12.2.4 Life-Cycle Costs ................................................................................ 108
 

12.3 State Summary ................................................................................................. 109
 

13 Nevada.................................................................................................................... 111
 

13.1 Percentage Savings........................................................................................... 111
 

13.1.1 Energy Use ........................................................................................ 112
 

13.1.2 Energy Costs ...................................................................................... 112
 

13.1.3 Energy-related Carbon Emissions Reduction.................................... 113
 

13.1.4 Life-Cycle Costs ................................................................................ 114
 

13.1.5 City Comparisons .............................................................................. 115
 

13.2 Total Savings.................................................................................................... 117
 

13.2.1 Energy Use ........................................................................................ 118
 

13.2.2 Energy Costs ...................................................................................... 119
 

13.2.3 Energy-related Carbon Emissions ..................................................... 121
 

13.2.4 Life-Cycle Costs ................................................................................ 122
 

13.3 State Summary ................................................................................................. 124
 

14 New Mexico............................................................................................................ 125
 

14.1 Percentage Savings........................................................................................... 125
 

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14.1.1 Statewide Building Comparison ........................................................ 125
 

14.1.2 City Comparisons .............................................................................. 127
 

14.2 Total Savings.................................................................................................... 128
 

14.2.1 Energy Use ........................................................................................ 128
 

14.2.2 Energy Costs ...................................................................................... 129
 

14.2.3 Energy-related Carbon Emissions ..................................................... 131
 

14.2.4 Life-Cycle Costs ................................................................................ 132
 

14.3 State Summary ................................................................................................. 133
 

15 Oregon.................................................................................................................... 135
 

15.1 Percentage Savings........................................................................................... 135
 

15.1.1 Statewide Building Comparison ........................................................ 135
 

15.1.2 City Comparisons .............................................................................. 137
 

15.2 Total Savings.................................................................................................... 138
 

15.2.1 Energy Use ........................................................................................ 138
 

15.2.2 Energy Costs ...................................................................................... 140
 

15.2.3 Energy-related Carbon Emissions ..................................................... 141
 

15.2.4 Life-Cycle Costs ................................................................................ 142
 

15.3 State Summary ................................................................................................. 144
 

16 Utah ........................................................................................................................ 145
 

16.1 Percentage Savings........................................................................................... 145
 

16.1.1 Statewide Building Comparison ........................................................ 145
 

16.1.2 City Comparisons .............................................................................. 147
 

16.2 Total Savings.................................................................................................... 148
 

16.2.1 Energy Use ........................................................................................ 148
 

16.2.2 Energy Costs ...................................................................................... 149
 

16.2.3 Energy-related Carbon Emissions ..................................................... 151
 

16.2.4 Life-Cycle Costs ................................................................................ 152
 

16.3 State Summary ................................................................................................. 153
 

17 Washington ............................................................................................................ 155
 

17.1 Percentage Savings........................................................................................... 155
 

17.1.1 Statewide Building Comparison ........................................................ 156
 

17.1.2 City Comparisons .............................................................................. 157
 

17.2 Total Savings.................................................................................................... 158
 

17.2.1 Energy Use ........................................................................................ 158
 

17.2.2 Energy Costs ...................................................................................... 160
 

17.2.3 Energy-related Carbon Emissions ..................................................... 162
 

17.2.4 Life-Cycle Costs ................................................................................ 163
 

17.3 State Summary ................................................................................................. 164
 

18 Wyoming ................................................................................................................ 165
 

18.1 Percentage Savings........................................................................................... 165
 

18.1.1 Energy Use ........................................................................................ 166
 

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18.1.2 Energy Costs ...................................................................................... 167
 

18.1.3 Energy-related Carbon Emissions ..................................................... 167
 

18.1.4 Life-Cycle Costs ................................................................................ 168
 

18.1.5 City Comparisons .............................................................................. 169
 

18.2 Total Savings.................................................................................................... 171
 

18.2.1 Energy Use ........................................................................................ 171
 

18.2.2 Energy Costs ...................................................................................... 173
 

18.2.3 Energy-related Carbon Emissions ..................................................... 174
 

18.2.4 Life-Cycle Costs ................................................................................ 176
 

18.3 State Summary ................................................................................................. 177
 

19 State Comparisons for the Adoption of the Low Energy Case Design ............ 179
 

19.1 Total Savings Comparison ............................................................................... 179
 

19.2 Percentage Change Comparison....................................................................... 184
 

19.2.1 3-Story Office Building ..................................................................... 184
 

19.2.2 Region-wide Results by Study Period Length................................... 187
 

19.2.3 Region-wide Results by Building Type............................................. 190
 

19.2.4 Region-wide Results by Climate Zone .............................................. 191
 

20 Discussion............................................................................................................... 195
 

20.1 Key Findings .................................................................................................... 195
 

20.2 Limitations and Future Research...................................................................... 197
 

References ...................................................................................................................... 201
 

A Building and Energy Characteristics .................................................................. 205
 

B Additional BIRDS Database Results ................................................................... 209
 

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List of Figures 

Figure 2-1 Cities and Climate Zones ................................................................................. 8
 

Figure 19-1 Average Energy Use Savings by State, 3-Story Office Building,
 

10-Year ...................................................................................................... 185
 

Figure 19-2 Average Energy Cost Savings by State, 3-Story Office Building,
 

10-Year ...................................................................................................... 186
 

Figure 19-3 Average Energy-related Carbon Emissions Reduction by State,
 

3-Story Office Building, 10-Year.............................................................. 186
 

Figure 19-4 Average Life-Cycle Cost Savings by State, 3-Story Office Building,
 

10-Year ...................................................................................................... 187
 

Figure 19-5 Average Change in Life-Cycle Costs by Building Type and Study
 

Period Length ............................................................................................ 190
 

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List of Tables 

Table 2-1 Building Characteristics .................................................................................... 5
 

Table 2-2 Energy Code by State/City for the West Census Region .................................. 7
 

Table 3-1 Energy Efficiency Component Requirements for Alternative Building
 

Designs ........................................................................................................ 10
 

Table 3-2 HVAC Energy Efficiency Requirements for Alternative Building
 

Designs ........................................................................................................ 11
 

Table 4-1 New Commercial Building Construction (West, 2003 through 2007) ............. 16
 

Table 5-1 Greenhouse Gas Global Warming Potentials .................................................. 19
 

Table 6-1 Average Annual Energy Use by Building Type and Energy Standard
 

Edition, Alaska ............................................................................................ 21
 

Table 6-2 Average Percentage Change in Energy Use from Adoption of Newer
 

Standard Editions, Alaska ........................................................................... 22
 

Table 6-3 Average Percentage Change in Energy Costs, 10-Year, Alaska ..................... 23
 

Table 6-4 Average Percentage Change in Energy-related Carbon Emissions, 10­

Year, Alaska ................................................................................................ 24
 

Table 6-5 Average Percentage Change in Life-Cycle Costs, 10-Year, Alaska ............... 25
 

Table 6-6 Average Percentage Change in Energy Use from Adoption of Newer
 

Standard Editions by City, Alaska .............................................................. 26
 

Table 6-7 Average Percentage Change in Energy Costs by City, 10-Year, Alaska ........ 26
 

Table 6-8 Average Percentage Change in Carbon Emissions by City, 10-Year,
 

Alaska .......................................................................................................... 27
 

Table 6-9 Average Percentage Change in Life-Cycle Costs by City, 10-Year,
 

Alaska .......................................................................................................... 27
 

Table 6-10 Average Per Unit Change in Annual Energy Use, Alaska ............................ 28
 

Table 6-11 Statewide Change in Annual Energy Use for One Year of
 

Construction, Alaska ................................................................................... 29
 

Table 6-12 Average Per Unit Change in Energy Costs, 10-Year, Alaska ....................... 30
 

Table 6-13 Statewide Change in Energy Costs for One Year of Construction,
 

10-Year, Alaska ........................................................................................... 31
 

Table 6-14 Average Per Unit Change in Carbon Emissions, 10-Year, Alaska ............... 32
 

Table 6-15 Statewide Change in Total Carbon Emissions for One Year of
 

Construction, 10-Year, Alaska – Metric Tons ............................................ 33
 

Table 6-16 Average Per Unit Change in Life-Cycle Costs, 10-Year, Alaska ................. 33
 

Table 6-17 Statewide Change in Life-Cycle Costs for One Year of Construction,
 

10-Year, Alaska ........................................................................................... 34
 

Table 7-1 Average Annual Energy Use by Building Type and Standard Edition,
 

Arizona ........................................................................................................ 37
 

Table 7-2 Average Percentage Change in Energy Use from Adoption of Newer
 

Standard Editions, Arizona ......................................................................... 38
 

Table 7-3 Average Percentage Change in Energy Costs, 10-Year, Arizona ................... 39
 

Table 7-4 Average Percentage Change in Energy-related Carbon Emissions, 10­

Year, Arizona .............................................................................................. 40
 

Table 7-5 Average Percentage Change in Life-Cycle Costs, 10-Year, Arizona ............. 41
 

Table 7-6 Average Percentage Change in Energy Use from Adoption of Newer
 

Standard Editions by City, Arizona............................................................. 42
 

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Table 7-7 Average Percentage Change in Energy Costs by City, 10-Year, 

Arizona ........................................................................................................ 43
 

Table 7-8 Average Percentage Change in Carbon Emissions by City, 10-Year,
 

Arizona ........................................................................................................ 43
 

Table 7-9 Average Percentage Change in Life-Cycle Costs by City, 10-Year,
 

Arizona ........................................................................................................ 44
 

Table 7-10 Average Per Unit Change in Annual Energy Use, Arizona .......................... 45
 

Table 7-11 Statewide Change in Annual Energy Use for One Year of
 

Construction, Arizona ................................................................................. 45
 

Table 7-12 Average Per Unit Change in Energy Costs, 10-Year, Arizona ..................... 46
 

Table 7-13 Statewide Change in Energy Costs for One Year of Construction,
 

10-Year, Arizona ......................................................................................... 47
 

Table 7-14 Average Per Unit Change in Carbon Emissions, 10-Year, Arizona.............. 48
 

Table 7-15 Statewide Change in Total Carbon Emissions for One Year of
 

Construction, 10-Year, Arizona – Metric Tons........................................... 49
 

Table 7-16 Average Per Unit Change in Life-Cycle Costs, 10-Year, Arizona................ 49
 

Table 7-17 Statewide Change in Life-Cycle Costs for One Year of Construction,
 

10-Year, Arizona ......................................................................................... 50
 

Table 8-1 Average Annual Energy Use by Building Type and Standard Edition,
 

California..................................................................................................... 53
 

Table 8-2 Average Percentage Change from Adoption of Newer Standard
 

Editions, 10-Year, California ...................................................................... 54
 

Table 8-3 Average Percentage Change from Adoption of Newer Standard
 

Editions by City, 10-Year, California ......................................................... 56
 

Table 8-4 Average Per Unit Change in Annual Energy Use, California ......................... 57
 

Table 8-5 Statewide Change in Annual Energy Use for One Year of
 

Construction, California .............................................................................. 58
 

Table 8-6 Average Per Unit Change in Energy Costs, 10-Year, California .................... 59
 

Table 8-7 Statewide Change in Energy Costs for One Year of Construction,
 

10-Year, California...................................................................................... 59
 

Table 8-8 Average Per Unit Change in Carbon Emissions, 10-Year, California ............ 60
 

Table 8-9 Statewide Change in Total Carbon Emissions for One Year of
 

Construction, 10-Year, California – Metric Tons ....................................... 61
 

Table 8-10 Average Per Unit Change in Life-Cycle Costs, 10-Year, California ............ 61
 

Table 8-11 Statewide Change in Life-Cycle Costs for One Year of Construction,
 

10-Year, California...................................................................................... 62
 

Table 9-1 Average Annual Energy Use by Building Type and Standard Edition,
 

Colorado ...................................................................................................... 63
 

Table 9-2 Average Percentage Change in Energy Use from Adoption of Newer
 

Standard Editions, Colorado ....................................................................... 64
 

Table 9-3 Average Percentage Change in Energy Costs, 10-Year, Colorado ................. 65
 

Table 9-4 Average Percentage Change in Energy-related Carbon Emissions, 10­

Year, Colorado ............................................................................................ 66
 

Table 9-5 Average Percentage Change in Life-Cycle Costs, 10-Year, Colorado ........... 67
 

Table 9-6 Average Percentage Change in Energy Use from Adoption of Newer
 

Standard Editions by City, Colorado........................................................... 68
 

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Table 9-7 Average Percentage Change in Energy Costs by City, 10-Year, 

Colorado ...................................................................................................... 68
 

Table 9-8 Average Percentage Change in Carbon Emissions by City, 10-Year,
 

Colorado ...................................................................................................... 69
 

Table 9-9 Average Percentage Change in Life-Cycle Costs by City, 10-Year,
 

Colorado ...................................................................................................... 69
 

Table 9-10 Average Per Unit Change in Annual Energy Use, Colorado ........................ 70
 

Table 9-11 Statewide Change in Annual Energy Use for One Year of
 

Construction, Colorado ............................................................................... 71
 

Table 9-12 Average Per Unit Change in Energy Costs, 10-Year, Colorado ................... 72
 

Table 9-13 Statewide Change in Energy Costs for One Year of Construction, 10­

Year, Colorado ............................................................................................ 73
 

Table 9-14 Average Per Unit Change in Carbon Emissions, 10-Year, Colorado............ 73
 

Table 9-15 Statewide Change in Total Carbon Emissions for One Year of
 

Construction, 10-Year, Colorado – Metric Tons......................................... 74
 

Table 9-16 Average Per Unit Change in Life-Cycle Costs, 10-Year, Colorado.............. 75
 

Table 9-17 Statewide Change in Life-Cycle Costs for One Year of Construction,
 

10-Year, Colorado ....................................................................................... 76
 

Table 10-1 Average Annual Energy Use by Building Type and Standard Edition,
 

Hawaii ......................................................................................................... 79
 

Table 10-2 Average Percentage Change in Energy Use from Adoption of Newer
 

Standard Editions, Hawaii ........................................................................... 80
 

Table 10-3 Average Percentage Change in Energy Costs, 10-Year, Hawaii................... 81
 

Table 10-4 Average Percentage Change in Energy-related Carbon Emissions, 10­

Year, Hawaii................................................................................................ 82
 

Table 10-5 Average Percentage Change in Life-Cycle Costs, 10-Year, Hawaii ............. 82
 

Table 10-6 Average Percentage Change in Energy Use from Adoption of Newer
 

Standard Editions by City, Hawaii .............................................................. 83
 

Table 10-7 Average Percentage Change in Energy Costs by City, 10-Year,
 

Hawaii ......................................................................................................... 83
 

Table 10-8 Average Percentage Change in Carbon Emissions by City, Hawaii ............. 84
 

Table 10-9 Average Percentage Change in Life-Cycle Costs by City, 10-Year,
 

Hawaii ......................................................................................................... 84
 

Table 10-10 Average Per Unit Change in Annual Energy Use, Hawaii.......................... 85
 

Table 10-11 Statewide Change in Annual Energy Use for One Year of
 

Construction, Hawaii................................................................................... 85
 

Table 10-12 Average Per Unit Change in Energy Costs, 10-Year, Hawaii..................... 86
 

Table 10-13 Statewide Change in Energy Costs for One Year of Construction,
 

10-Year, Hawaii .......................................................................................... 87
 

Table 10-14 Average Per Unit Change in Carbon Emissions, 10-Year, Hawaii ............. 88
 

Table 10-15 Statewide Change in Total Carbon Emissions for One Year of
 

Construction, 10-Year, Hawaii – Metric Tons ............................................ 89
 

Table 10-16 Average Per Unit Change in Life-Cycle Costs, 10-Year, Hawaii ............... 89
 

Table 10-17 Statewide Change in Life-Cycle Costs for One Year of Construction,
 

10-Year, Hawaii .......................................................................................... 90
 

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Table 11-1 Average Annual Energy Use by Building Type and Standard Edition, 

Idaho ............................................................................................................ 91
 

Table 11-2 Average Percentage Change from Adoption of Newer Standard
 

Editions, 10-Year, Idaho ............................................................................. 92
 

Table 11-3 Average Percentage Change from Adoption of Newer Standard
 

Editions by City, 10-Year, Idaho ................................................................ 93
 

Table 11-4 Average Per Unit Change in Annual Energy Use, Idaho .............................. 94
 

Table 11-5 Statewide Change in Annual Energy Use for One Year of
 

Construction, Idaho ..................................................................................... 95
 

Table 11-6 Average Per Unit Change in Energy Costs, 10-Year, Idaho ......................... 96
 

Table 11-7 Statewide Change in Energy Costs for One Year of Construction,
 

10-Year, Idaho ............................................................................................. 97
 

Table 11-8 Average Per Unit Change in Carbon Emissions, 10-Year, Idaho ................. 97
 

Table 11-9 Statewide Change in Total Carbon Emissions for One Year of
 

Construction, 10-Year, Idaho – Metric Tons .............................................. 98
 

Table 11-10 Average Per Unit Change in Life-Cycle Costs, 10-Year, Idaho ................. 99
 

Table 11-11 Statewide Change in Life-Cycle Costs for One Year of Construction,
 

10-Year, Idaho ............................................................................................. 99
 

Table 12-1 Average Annual Energy Use by Building Type and Standard
 

Editions, Montana ..................................................................................... 101
 

Table 12-2 Average Percentage Change from Adoption of Standard Editions, 10­

Year, Montana ........................................................................................... 102
 

Table 12-3 Average Percentage Change from Adoption of Newer Standard
 

Editions by City, 10-Year, Montana ......................................................... 103
 

Table 12-4 Average Per Unit Change in Annual Energy Use, Montana ....................... 104
 

Table 12-5 Statewide Change in Annual Energy Use for One Year of
 

Construction, Montana .............................................................................. 105
 

Table 12-6 Average Per Unit Change in Energy Costs, 10-Year, Montana .................. 106
 

Table 12-7 Statewide Change in Energy Costs for One Year of Construction,
 

10-Year, Montana...................................................................................... 106
 

Table 12-8 Average Per Unit Change in Carbon Emissions, 10-Year, Montana .......... 107
 

Table 12-9 Statewide Change in Total Carbon Emissions for One Year of
 

Construction, 10-Year, Montana – Metric Tons ....................................... 108
 

Table 12-10 Average Per Unit Change in Life-Cycle Costs, 10-Year, Montana .......... 108
 

Table 12-11 Statewide Change in Life-Cycle Costs for One Year of Construction,
 

10-Year, Montana...................................................................................... 109
 

Table 13-1 Average Annual Energy Use by Building Type and Standard
 

Editions, Nevada ....................................................................................... 111
 

Table 13-2 Average Percentage Change in Energy Use from Adoption of Newer
 

Standard Editions, Nevada ........................................................................ 112
 

Table 13-3 Average Percentage Change in Energy Costs, 10-Year, Nevada ................ 113
 

Table 13-4 Average Percentage Change in Energy-related Carbon Emissions, 10­

Year, Nevada ............................................................................................. 114
 

Table 13-5 Average Percentage Change in Life-Cycle Costs, 10-Year, Nevada .......... 115
 

Table 13-6 Average Percentage Change in Energy Use from Adoption of Newer
 

Standard Editions by City, Nevada ........................................................... 116
 

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Table 13-7 Average Percentage Change in Energy Costs by City, 10-Year, 

Nevada ....................................................................................................... 116
 

Table 13-8 Average Percentage Change in Carbon Emissions by City, Nevada .......... 117
 

Table 13-9 Average Percentage Change in Life-Cycle Costs by City, 10-Year,
 

Nevada ....................................................................................................... 117
 

Table 13-10 Average Per Unit Change in Annual Energy Use, Nevada ....................... 118
 

Table 13-11 Statewide Change in Annual Energy Use for One Year of
 

Construction, Nevada ................................................................................ 119
 

Table 13-12 Average Per Unit Change in Energy Costs, 10-Year, Nevada .................. 120
 

Table 13-13 Statewide Change in Energy Costs for One Year of Construction,
 

10-Year, Nevada........................................................................................ 121
 

Table 13-14 Average Per Unit Change in Carbon Emissions, 10-Year, Nevada .......... 121
 

Table 13-15 Statewide Change in Total Carbon Emissions for One Year of
 

Construction, 10-Year, Nevada – Metric Tons ......................................... 122
 

Table 13-16 Average Per Unit Change in Life-Cycle Costs, 10-Year, Nevada ............ 123
 

Table 13-17 Statewide Change in Life-Cycle Costs for One Year of Construction,
 

10-Year, Nevada........................................................................................ 124
 

Table 14-1 Average Annual Energy Use by Building Type and Standard Edition,
 

New Mexico .............................................................................................. 125
 

Table 14-2 Average Percentage Change from Adoption of Newer Standard
 

Editions, 10-Year, New Mexico................................................................ 126
 

Table 14-3 Average Percentage Change from Adoption of Newer Standard
 

Editions by City, 10-Year, New Mexico ................................................... 127
 

Table 14-4 Average Per Unit Change in Annual Energy Use, New Mexico ................ 128
 

Table 14-5 Statewide Change in Annual Energy Use for One Year of
 

Construction, New Mexico ....................................................................... 129
 

Table 14-6 Average Per Unit Change in Energy Costs, 10-Year, New Mexico ........... 130
 

Table 14-7 Statewide Change in Energy Costs for One Year of Construction,
 

10-Year, New Mexico ............................................................................... 130
 

Table 14-8 Average Per Unit Change in Carbon Emissions, 10-Year, New
 

Mexico....................................................................................................... 131
 

Table 14-9 Statewide Change in Total Carbon Emissions for One Year of
 

Construction, 10-Year, New Mexico – Metric Tons................................. 132
 

Table 14-10 Average Per Unit Change in Life-Cycle Costs, 10-Year, New
 

Mexico....................................................................................................... 132
 

Table 14-11 Statewide Change in Life-Cycle Costs for One Year of Construction,
 

10-Year, New Mexico ............................................................................... 133
 

Table 15-1 Average Annual Energy Use by Building Type and Standard Edition,
 

Oregon ....................................................................................................... 135
 

Table 15-2 Average Percentage Change in Energy Use from Adoption of a
 

Newer Standard Edition, 10-Year, Oregon ............................................... 136
 

Table 15-3 Average Percentage Change in Energy Use from Adoption of Newer
 

Standard Editions by City, 10-Year, Oregon ............................................ 137
 

Table 15-4 Average Per Unit Change in Annual Energy Use, Oregon ......................... 139
 

Table 15-5 Statewide Change in Annual Energy Use for One Year of
 

Construction, Oregon ................................................................................ 139
 

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Table 15-6 Average Per Unit Change in Energy Costs, 10-Year, Oregon .................... 140
 

Table 15-7 Statewide Change in Energy Costs for One Year of Construction,
 

10-Year, Oregon ........................................................................................ 141
 

Table 15-8 Average Per Unit Change in Carbon Emissions, 10-Year, Oregon ............ 141
 

Table 15-9 Statewide Change in Total Carbon Emissions for One Year of
 

Construction, 10-Year, Oregon – Metric Tons ......................................... 142
 

Table 15-10 Average Per Unit Change in Life-Cycle Costs, 10-Year, Oregon ............ 143
 

Table 15-11 Statewide Change in Life-Cycle Costs for One Year of Construction,
 

10-Year, Oregon ........................................................................................ 143
 

Table 16-1 Average Annual Energy Use by Building Type and Standard Edition,
 

Utah ........................................................................................................... 145
 

Table 16-2 Average Percentage Change from Adoption of Newer Standard
 

Editions, 10-Year, Utah ............................................................................. 146
 

Table 16-3 Average Percentage Change from Adoption of Newer Standard
 

Editions by City, 10-Year, Utah ................................................................ 147
 

Table 16-4 Average Per Unit Change in Annual Energy Use, Utah ............................. 148
 

Table 16-5 Statewide Change in Annual Energy Use for One Year of
 

Construction, Utah .................................................................................... 149
 

Table 16-6 Average Per Unit Change in Energy Costs, 10-Year, Utah ........................ 150
 

Table 16-7 Statewide Change in Energy Costs for One Year of Construction,
 

10-Year, Utah ............................................................................................ 150
 

Table 16-8 Average Per Unit Change in Carbon Emissions, 10-Year, Utah................. 151
 

Table 16-9 Statewide Change in Total Carbon Emissions for One Year of
 

Construction, 10-Year, Utah – Metric Tons.............................................. 152
 

Table 16-10 Average Per Unit Change in Life-Cycle Costs, 10-Year, Utah................. 152
 

Table 16-11 Statewide Change in Life-Cycle Costs for One Year of Construction,
 

10-Year, Utah ............................................................................................ 153
 

Table 17-1 Average Annual Energy Use by Building Type and Standard Edition,
 

Washington................................................................................................ 155
 

Table 17-2 Average Percentage Change from Adoption of a Newer Standard
 

Edition, 10-Year, Washington................................................................... 156
 

Table 17-3 Average Percentage Change from Adoption of Newer Standard
 

Editions by City, 10-Year, Washington .................................................... 158
 

Table 17-4 Average Per Unit Change in Annual Energy Use, Washington .................. 159
 

Table 17-5 Statewide Change in Annual Energy Use for One Year of
 

Construction, Washington ......................................................................... 160
 

Table 17-6 Average Per Unit Change in Energy Costs, 10-Year, Washington ............. 161
 

Table 17-7 Statewide Change in Energy Costs for One Year of Construction,
 

10-Year, Washington ................................................................................ 161
 

Table 17-8 Average Per Unit Change in Carbon Emissions, 10-Year, Washington ..... 162
 

Table 17-9 Statewide Change in Total Carbon Emissions (t) for One Year of
 

Construction, 10-Year, Washington – Metric Tons .................................. 163
 

Table 17-10 Average Per Unit Change in Life-Cycle Costs, 10-Year, Washington ..... 163
 

Table 17-11 Statewide Change in Life-Cycle Costs for One Year of Construction,
 

10-Year, Washington ................................................................................ 164
 

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Table 18-1 Average Annual Energy Use by Building Type and Standard Edition, 

Wyoming ................................................................................................... 165
 

Table 18-2 Average Percentage Change in Energy Use from Adoption of Newer
 

Standard Editions, Wyoming .................................................................... 166
 

Table 18-3 Average Percentage Change in Energy Costs, 10-Year, Wyoming ............ 167
 

Table 18-4 Average Percentage Change in Energy-related Carbon Emissions, 10­

Year, Wyoming ......................................................................................... 168
 

Table 18-5 Average Percentage Change in Life-Cycle Costs, 10-Year, Wyoming ...... 169
 

Table 18-6 Average Percentage Change in Energy Use from Adoption of Newer
 

Standard Editions by City, Wyoming ....................................................... 169
 

Table 18-7 Average Percentage Change in Energy Costs by City, 10-Year,
 

Wyoming ................................................................................................... 170
 

Table 18-8 Average Percentage Change in Carbon Emissions by City, 10-Year,
 

Wyoming ................................................................................................... 170
 

Table 18-9 Average Percentage Change in Life-Cycle Costs by City, 10-Year,
 

Wyoming ................................................................................................... 171
 

Table 18-10 Average Per Unit Change in Annual Energy Use, Wyoming ................... 172
 

Table 18-11 Statewide Change in Annual Energy Use for One Year of
 

Construction, Wyoming ............................................................................ 172
 

Table 18-12 Average Per Unit Change in Energy Costs, 10-Year, Wyoming .............. 173
 

Table 18-13 Statewide Change in Energy Costs for One Year of Construction,
 

10-Year, Wyoming .................................................................................... 174
 

Table 18-14 Average Per Unit Change in Carbon Emissions, 10-Year, Wyoming ...... 175
 

Table 18-15 Statewide Change in Total Carbon Emissions for One Year of
 

Construction, 10-Year, Wyoming – Metric Tons ..................................... 176
 

Table 18-16 Average Per Unit Change in Life-Cycle Costs, 10-Year, Wyoming ........ 176
 

Table 18-17 Statewide Change in Life-Cycle Costs for One Year of Construction,
 

10-Year, Wyoming .................................................................................... 177
 

Table 19-1 Total Reductions by State for Adoption of the LEC Design, 10-Year........ 180
 

Table 19-2 Energy Use Reduction per Unit of Floor Area for Adoption of the
 

LEC Design by State, 10-Year .................................................................. 181
 

Table 19-3 Energy Cost Reduction per kWh of Energy Use Reduction for
 

Adoption of the LEC Design by State, 10-Year........................................ 182
 

Table 19-4 Carbon Reduction per GWh of Energy Use Reduction for Adoption
 

of the LEC Design by State, 10-Year ........................................................ 183
 

Table 19-5 Life-Cycle Cost Reductions per Unit of New Floor Area for Adoption
 

of the LEC Design by State, 10-Year ........................................................ 184
 

Table 19-6 Average Percentage Change by State from Region-wide Adoption of
 

the LEC design, 3-Story Office Building, 10-Year ................................... 185
 

Table 19-7 West Region Average Percentage Change in Energy Use by Building
 

Type ........................................................................................................... 188
 

Table 19-8 West Region Average Percentage Change in Energy Costs by
 

Building Type and Study Period Length ................................................... 188
 

Table 19-9 West Region Average Percentage Change in Carbon Emissions by
 

Building Type............................................................................................ 189
 

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Table 19-10 West Region Average Percentage Change in Life-Cycle Costs by 

Building Type and Study Period Length ................................................... 189 

Table 19-11 West Region Percentage Change for LEC by Building Type, 

10-Year ...................................................................................................... 191 

Table 19-12 Average Percentage Change for LEC by Climate Zone............................ 191 

Table 19-13 Average Percentage Change in Energy Use for LEC by Climate 

Zone and State Energy Code ..................................................................... 192 

Table 19-14 Average Percentage Change in Energy Costs for LEC by Climate 

Zone and State Energy Code ..................................................................... 192 

Table 19-15 Average Percentage Change in Carbon Emissions for LEC by 

Climate Zone and State Energy Code ....................................................... 193 

Table 19-16 Average Percentage Change in Life-Cycle Costs for LEC by Climate 

Zone and State Energy Code ..................................................................... 193 

Table A-1 CBECS Categories and Subcategories .......................................................... 205 

Table A-2 New Commercial Building Construction Volume for 2003 through 

2007 by State and Building Type .............................................................. 206 

Table A-3 New Commercial Building Construction Share by State and Building 

Type ........................................................................................................... 207 

Table A-4 Electricity Generation CO2, CH4, and N2O Emissions Rates by State ......... 207 

Table B-1 4-Story Apartment Building Summary Table for LEC and 10-Year 

Study Period .............................................................................................. 209 

Table B-2 6-Story Apartment Building Summary Table for LEC and 10-Year 

Study Period .............................................................................................. 209 

Table B-3 4-Story Dormitory Summary Table for LEC and 10-Year Study Period ..... 210 

Table B-4 6-Story Dormitory Summary Table for LEC and 10-Year Study Period ..... 210 

Table B-5 15-Story Hotel Building Summary Table for LEC and 10-Year Study 

Period ........................................................................................................ 211 

Table B-6 2-Story High School Summary Table for LEC and 10-Year Study 

Period ........................................................................................................ 211 

Table B-7 8-Story Office Building Summary Table for LEC and 10-Year Study 

Period ........................................................................................................ 212 

Table B-8 16-Story Office Building Summary Table for LEC and 10-Year 

Study Period .............................................................................................. 212 

Table B-9 1-Story Retail Store Summary Table for LEC and 10-Year Study 

Period ........................................................................................................ 213 

Table B-10 1-Story Restaurant Summary Table for LEC and 10-Year Study 

Period ........................................................................................................ 213 

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List of Acronyms
 

Acronym Definition 

AEO Applied Economics Office 

AIRR Adjusted Internal Rate of Return 

ASHRAE American Society of Heating, Refrigerating and Air-Conditioning Engineers 

BIRDS Building Industry Reporting and Design for Sustainability 

CBECS Commercial Building Energy Consumption Survey 

CH4 Methane 

CO2 Carbon Dioxide 

CO2e Carbon Dioxide Equivalent 

DOE Department of Energy 

EEFG EnergyPlus Example File Generator 

eGRID Emissions and Generation Resource Integrated Database 

EIA Energy Information Administration 

EL Engineering Laboaratory 

EPA Environmental Protection Agency 

FEMP Federal Energy Management Program 

FERC Federal Energy Regulatory Commission 

HVAC Heating, Ventilating, and Air Conditioning 

I-P Inch-Pounds (Customary Units) 

IECC International Energy Code Council 

ISO International Organization for Standardization 

LCA Life-Cycle Assessment 

LCC Life-Cycle Cost 

LEC Low Energy Case 

MRR Maintenance, Repair, and Replacement 

N2O Nitrous Oxide 

NIST National Institute of Standards and Technology 

PNNL Pacific Northwest National Laboratory 

ROI Return On Investment 

S-I System International (Metric Units) 

SEER Seasonal Energy Efficiency Ratio 

SHGC Solar Heat Gain Coefficient 

SPV Single Present Value 

xxiv
 
 

Acronym Definition 

UPV* Uniform Present Value Modified for Fuel Price Escalation 

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Executive Summary 

Executive Summary 

Energy efficiency requirements in energy codes for commercial buildings vary across 

states, and many states have not yet adopted the latest energy standard edition. As of 

December 2011, state energy code adoptions range across editions of the American 

Society of Heating, Refrigerating and Air-Conditioning Engineers Energy Standard for 

Buildings Except Low-Rise Residential Buildings (ASHRAE 90.1-2001, -2004, 

and -2007). Some states in the United States do not have a code requirement for energy 

efficiency, leaving it up to the locality or jurisdiction to set its own requirement. There 

may be significant energy and cost savings to be realized by states, particularly those 

states that have not yet adopted an energy code, if they were to adopt more energy 

efficient commercial building energy standard editions. 

The results of this report are based on analysis of the thirteen states in the West Census 

Region using the Building Industry Reporting and Design for Sustainability (BIRDS) 

database. BIRDS includes 12 540 whole-building energy simulation estimates covering 

11 building types in 228 cities across all U.S. states for 9 study period lengths. The 

performance of buildings designed to meet current state energy codes is compared to 

their performance when meeting alternative building energy standard editions to 

determine whether more stringent energy standard editions are cost-effective in reducing 

energy consumption and energy-related carbon emissions. Each state energy code is also 

compared to a “Low Energy Case” (LEC) building design that increases energy 

efficiency beyond the ASHRAE 90.1-2007 design. 

Three states in the West Census Region have not yet adopted a state energy code for 

commercial buildings: Alaska, Arizona, and Wyoming. For all cities in Alaska and 

Wyoming and the cities in Arizona that have not adopted a local energy code, adoption of 

ASHRAE 90.1-2001 leads to reductions in energy use, energy costs, and energy-related 

carbon emissions, but not in a life-cycle cost-effective manner. In Arizona and Wyoming, 

ASHRAE 90.1-2004 leads to greater reductions in energy use, energy costs, and carbon 

emissions than ASHRAE 90.1-2001, and is life-cycle cost-effective to adopt. Alaska 

realizes an increase in energy use from adopting ASHRAE 90.1-2004 while decreasing 

energy costs, carbon emissions, and life-cycle costs. The shift in fuel consumption from 

electricity to natural gas allows energy use to increase while energy costs decrease. All 

three states realize reductions in energy use, energy costs, carbon emissions, and 

life-cycle costs from adopting ASHRAE 90.1-2007. 

Colorado is the only state in the West Census Region that has adopted ASHRAE 

90.1-2001 as its state energy code for commercial buildings. Colorado would realize 

reductions in energy use, energy costs, and energy-related carbon emissions as well as 

life-cycle costs from adopting ASHRAE 90.1-2004. Adopting ASHRAE 90.1-2007 would 

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Executive Summary 

lead to greater reductions in energy use, energy costs, carbon emissions, and life-cycle 

costs than adopting ASHRAE 90.1-2004. 

Hawaii and Nevada are the states in the West Census Region that have adopted ASHRAE 

90.1-2004 as their state energy code for commercial buildings. Both states would realize 

cost-effective reductions in energy use, energy costs, and energy-related carbon 

emissions from adopting ASHRAE 90.1-2007. Nevada realizes greater total life-cycle cost 

savings than total energy cost savings because the relaxation of the window U-factor and 

SHGC requirements decreases total construction costs while still decreasing total energy 

use for the state. 

The adoption of the LEC design is analyzed for all thirteen states. The LEC design goes 

beyond ASHRAE 90.1-2007 by setting stricter building envelope requirements, lower 

lighting densities, and requiring daylighting controls as well as requiring overhangs for 

warmer climate zones. There are several factors that impact the percentage savings from 

adopting the LEC design for all states in the West Census Region, including the current 

state energy code, selected study period length, building type, and climate zone of the 

location. 

The region-wide adoption of the LEC design as the commercial building energy code for 

all building types significantly decreases energy use (18.5 %), energy costs (23.7 %), and 

carbon emissions (23.2 %), on average, while reducing life-cycle costs (1.1 %), on 

average, for a 10-year study period. Although the LEC design leads to reductions for all 

states, the magnitude of the reductions varies according to each state’s adopted energy 

code. The states that have not adopted ASHRAE 90.1-2007 realize the greatest percentage 

savings in energy use, energy costs, and carbon emissions. The states that have adopted 

ASHRAE 90.1-2004 realize the greatest percentage reductions in life-cycle costs. The 

states that have already adopted ASHRAE 90.1-2007 also realize percentage reductions in 

life-cycle costs. Two of the three states that have no state energy code realize an average 

percentage increase in life-cycle costs relative to ASHRAE 90.1-1999. 

The study period length impacts the resulting reductions in life-cycle costs. As the study 

period length increases from 5 years to 15 years, the number of building types that are 

cost-effective increases from eight to all eleven. The study period length is an important 

determinant of cost-effectiveness and size of the percentage changes in life-cycle costs. 

The climate zone of a location impacts the percentage reduction in energy use, energy 

costs, and carbon emissions. After controlling for each state’s energy code, cities located 

in warmer climates tend to realize greater average percentage reductions in these 

measures. 

Different building types realize different regional average percentage reductions in 

energy use, energy costs, and carbon emissions for a 10-year study period. High schools, 

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Executive Summary 

16-story office buildings, and hotels realize the smallest reductions while restaurants and 

3-story office buildings realize the greatest reductions. The greatest percentage reductions 

in life-cycle costs are also realized by restaurants and 3- and 8-story office buildings 

while the only percentage increase is realized by 16-story office buildings. 

The magnitude of a building type’s average percentage change is not necessarily 

correlated with its changes in total energy use, energy costs, and energy-related carbon 

emissions relative to other building types. For example, high schools tend to realize some 

of the smallest percentage reductions, but some of the greatest total reductions in energy 

use, energy costs, and energy-related carbon emissions. Total reductions are driven 

largely by total new floor area constructed for the building type in a state. The adoption 

of the LEC design would lead to greater aggregate reductions in energy use in California 

than in Wyoming because the amount of newly constructed floor area for 2003 to 2007 

was 63 higher times in California. 

A number of other factors impact total reductions in energy use, energy costs, and carbon 

emissions: state energy codes, energy rates, and carbon emissions rates. The greatest 10­

year reductions in energy use per unit of floor area resulting from adoption of the LEC 

design are realized by the four states that have no state energy code or have adopted 

ASHRAE 90.1-2001, ranging from 333 kWh/m2 (106 kBtu/ft2

) to 390 kWh/m2 

(124 kBtu/ft2). The states that have adopted ASHRAE 90.1-2004 or -2007 realize 

reductions ranging from 141 kWh/m2 (45 kBtu/ft2) to 258 kWh/m2 (82 kBtu/ft2). States 

with the highest electricity rates tend to realize the largest reductions in energy costs per 

unit of energy consumption reduced. Similarly, states with higher CO2e emission rates 

per unit of electricity generated tend to realize greater reductions in emissions per unit of 

energy consumption reduced. The greater the offset of electricity consumption reductions 

with natural gas consumption increases, the greater the reduction in both energy costs and 

carbon emissions per unit of energy consumption reduced. 

This study is limited in scope and would be strengthened by including sensitivity 

analysis, expanding the BIRDS database, and enabling public access to all the results. 

Combining these results with detailed analysis of the states in the other three census 

regions would make possible an estimate of the nationwide impact of adopting more 

stringent building energy codes. Expansion of the environmental assessment beyond 

energy-related carbon emissions to include building materials and a full range of both 

life-cycle environmental impacts and life-cycle stages, from cradle to grave, would 

enable comprehensive sustainability assessment. Additional energy efficiency measures, 

fuel types, discount rates, and building types would also expand the scope of the 

database. Also, given that new buildings account for a small fraction of the entire 

building stock, incorporating analysis of energy retrofits to these same prototype 

buildings would increase the coverage of the database. 

xxviii
 
 

 

 

 

 

 

Executive Summary 

The extensive BIRDS database can be used to answer many more questions than posed in 

this report, and will be made available to the public through a simple-to-use software tool 

that allows others access to the database for their own research on building energy 

efficiency and sustainability. These improvements are underway, with more detailed 

reporting and release of the BIRDS software scheduled for 2013. 

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Introduction 

1	 Introduction 

1.1 Background and Purpose 

Energy efficiency requirements in current energy codes for commercial buildings vary 

across states, and many states have not yet adopted the latest energy efficiency standard 

editions. As of December 2011, state energy code adoptions range across editions of the 

American Society of Heating, Refrigerating and Air-Conditioning Engineers Energy 

Standard for Buildings Except Low-Rise Residential Buildings (ASHRAE 

90.1-2001, -2004, and -2007). ASHRAE Standard 90.1 is the industry consensus standard 

to establish the minimum energy-efficient requirements of buildings, other than low-rise 

residential buildings. Some states do not have a code requirement for energy efficiency, 

leaving it up to the locality or jurisdiction to set its own requirement. There may be 

significant energy and cost savings to be realized by states if they were to adopt more 

energy efficient commercial building energy standard editions. 

The purpose of this study is to estimate the impacts that the adoption of more stringent 

energy codes for commercial buildings would have on building energy use, operational 

energy costs, energy-related carbon emissions, and building life-cycle costs for states 

located in the West Census Region. The results are analyzed for each state and across all 

states in the region to answer the following questions: 

•	 How much does each more stringent energy standard edition decrease building 

energy consumption, energy costs, and energy-related carbon emissions, in 

percentage terms, relative to the state’s current energy code? 

•	 Is adopting a more stringent energy standard edition life-cycle cost-effective? 

•	 Based on new construction in each state, how much can a state save in total energy 

consumption, energy costs, and energy-related carbon emissions over time? Are these 

savings obtained life-cycle cost-effectively? 

•	 Which states would realize the most significant savings from adopting newer energy 

standard editions, and what factors drive the relative savings across states? 

1.2 Literature Review 

Pacific Northwest National Laboratory (2009) estimates the impacts for each state of 

adopting the most recent edition of the ASHRAE 90.1 Standard as of 2009, ASHRAE 

90.1-2007, as the commercial building energy code relative to the state’s current energy 

code. For states without a state commercial building energy code, the baseline is 

assumed to be ASHRAE 90.1-1999 because it is considered to represent common practice 

in the industry. The annual energy use savings and energy cost savings are estimated for 

three Department of Energy (DOE) benchmark buildings -- a medium-sized office 

building, a non-refrigerated warehouse, and a mid-rise apartment building -- to represent 

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Introduction 

non-residential, semi-heated, and residential uses, respectively. The buildings are 

simulated in the EnergyPlus whole building energy software (DOE, 2009a) for 97 cities 

located across the U.S., ensuring that each climate zone in each state is represented. The 

study reports annual electricity and natural gas consumption per square foot of floor area 

for the buildings, assuming they are built to meet both the state’s current code and 

ASHRAE 90.1-2007. Based on these results, the percentage savings in energy and energy 

costs are calculated for the three building types for each state. The study does not 

compare energy use and energy costs across states. Life-cycle costs and carbon emissions 

are not considered in the study. 

Kneifel (2010) creates a framework to simultaneously analyze the impacts of improving 

energy efficiency on energy use, energy costs, life-cycle costs, and carbon emissions 

through an integrated design context for new commercial buildings. The paper compares 

the savings of constructing 11 prototype commercial buildings to meet the building 

envelope requirements of ASHRAE 90.1-2007 and a “Low Energy Case,” relative to 

ASHRAE 90.1-2004, for 16 cities in different climate zones across the contiguous United 

States. The paper finds minimal improvements in energy efficiency from building to meet 

ASHRAE 90.1-2007 relative to ASHRAE 90.1-2004 while significant savings is found by 

building to meet the “Low Energy Case.” The “Low Energy Case” is often cost-effective 

on a first cost basis and is always cost-effective over the longer study period lengths. 

Kneifel (2011a) expands on the framework and analysis in Kneifel (2010) by analyzing 

the impact of adopting the building envelope requirements of ASHRAE 90.1-2007 and a 

“Low Energy Case” relative to ASHRAE 90.1-2004 in terms of energy use, energy costs, 

energy-related carbon emissions, and life-cycle costs for 228 cities across the U.S. with at 

least one city in each state. Analysis includes 4 study period lengths (1, 10, 25, and 40 

years). The paper finds that, on average, the more energy efficient building designs are 

cost-effective. However, there is significant variation across states in terms of energy use 

savings and life-cycle cost-effectiveness driven by both climate and construction costs. 

There is also significant variation across cities within a state, even cities located within 

the same climate zone. These variations are a result of differences in local material and 

labor costs as well as energy costs. 

Kneifel (2013) analyzes 12 540 whole-building energy simulations in the BIRDS 

database covering 11 building types in 228 cities across all U.S. states for 9 study period 

lengths (1, 5, 10, 15, 20, 25, 30, 35, and 40 years). Current state energy code performance 

is compared to the performance of alternative ASHRAE 90.1 Standard editions to 

determine whether more stringent energy standard editions are cost-effective in reducing 

energy consumption and energy-related carbon emissions. This analysis includes a “Low 

Energy Case” (LEC) building design that increases energy efficiency beyond the 

ASHRAE 90.1-2007 design. Results are analyzed in detail for the ASHRAE 90.1-2007 

and LEC designs. Results are aggregated at the state level for seven states, Alaska, 

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Introduction 

Colorado, Florida, Maryland, Oregon, Tennessee, and Wisconsin, to estimate the 

magnitude of total energy use savings, energy cost savings, life-cycle cost savings and 

energy-related carbon emissions reductions that could be attained by adoption of a more 

stringent state energy code for commercial buildings. 

1.3 Approach 

This study uses the Building Industry Reporting and Design for Sustainability (BIRDS) 

database to analyze the benefits and costs of increasing building energy efficiency for 73 

cities located in the 13 states of the West Census Region. BIRDS is a compilation of 

whole building energy simulations, building construction cost data, maintenance, repair, 

and replacement rates and costs, and energy-related carbon emissions data for 11 building 

types in 228 cities across all U.S. states. The present analysis compares energy 

performance of buildings designed to each state’s current energy code for commercial 

buildings to the performance of more energy efficient building designs to determine the 

energy use savings, energy cost savings, and energy-related carbon emissions reductions, 

and the associated life-cycle costs resulting from adopting stricter standards as the state’s 

energy code. 

Results are analyzed both in percentage and total value terms. The percentage savings 

results allow for direct comparisons across energy standard editions, building types, study 

period lengths, climate zones, and cities both within each state and across states in the 

West Census Region. Results are aggregated to the state level to estimate the magnitude 

of total energy use savings, energy cost savings, and energy-related carbon emissions 

reductions that could be attained by adoption of a more stringent state energy code, and 

the associated total life-cycle costs. 

Results are summarized using both tables and figures. In cases where the material being 

discussed is of secondary importance, the associated table or figure is placed in the 

Appendices. The order in which tables and figures appear in the Appendices corresponds 

to the order in which they are cited in the text. 

3
 
Introduction 

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Study Design 

2 Study Design 

The BIRDS database used in this study was built following the framework developed in 

Kneifel (2010) and further expanded in Kneifel (2011a) and Kneifel (2013). This study 

analyzes whole building energy simulations, life-cycle costs, and life-cycle carbon 

emissions for 5 energy efficiency designs for 11 building types, 73 cities across the 

thirteen states in the West Census Region of the United States, and 9 study period 

lengths.1 

2.1 Building Types 

The building characteristics in Table 2-1 describe the 11 building types used in this study, 

which include 2 dormitories, 2 apartment buildings, a hotel, 3 office buildings, a school, a 

retail store, and a restaurant. The building types were selected based on a combination of 

factors, including fraction of building stock represented, variation in building 

characteristics, and ease of simulation design. These building types represent 46 % of the 

existing U.S. commercial building stock floor space.2 The prototype buildings range in 

size from 465 m2 (5000 ft2) to 41 806 m2 (450 000 ft2). The building abbreviations 

defined in Table 2-1 are used to represent the building types in tables throughout this 

study. 

Table 2-1 Building Characteristics 

Building Type Bldg. Abbr. Floors 

Floor 

Height 

m (ft) 

Wall Roof† Pct. 

Glazing 

Building Size 

m 2 (ft2

) 

Occupancy 

Type 

U.S. Floor 

Space (%) 

Dormitory DORMI04 4 3.66 (12) Mass IEAD 20 % 3097 (33 333) Lodging 7.1 % 

Dormitory DORMI06 6 3.66 (12) Steel IEAD 20 % 7897 (85 000) 

Hotel HOTEL15 15 3.05 (10) Steel IEAD 100 % 41 806 (450 000) 

Apartment APART04 4 3.05 (10) Mass IEAD 12 % 2787 (30 000) 

Apartment APART06 6 3.15 (10) Steel IEAD 14 % 5574 (60 000) 

School, High HIGHS02 2 4.57 (15) Mass IEAD 25 % 12 077 (130 000) Education 13.8 % 

Office OFFIC03 3 3.66 (12) Mass IEAD 20 % 1858 (20 000) Office 17.0 % 

Office OFFIC08 8 3.66 (12) Mass IEAD 20 % 7432 (80 000) 

Office OFFIC16 16 3.05 (10) Steel IEAD 100 % 24 155 (260 000) 

Retail Store RETAIL1 1 4.27 (14) Mass IEAD 10 % 743 (8000) Mercantile* 6.0 % 

Restaurant RSTRNT1 1 3.66 (12) Wood IEAD 30 % 465 (5000) Food Service 2.3 % 

*Only includes non-mall floor area. 

†IEAD = Insulation Entirely Above Deck 

1 See Kneifel (2011b) for additional details on the whole building energy simulations used in the BIRDS 

database. 

2 Based on the Commercial Building Energy Consumption Survey (CBECS) database 

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Study Design 

2.2 Building Designs 

Current state energy codes are based on different editions of the International Energy 

Conservation Code (IECC) or ASHRAE 90.1 Standard, which have requirements that 

vary based on a building’s characteristics and the climate zone of the building location.3 

For this study, the prescriptive requirements of the ASHRAE 90.1 Standard-equivalent 

design are used to meet current state energy codes and to define the alternative building 

designs. California has adopted the California Building Standards Code, otherwise known 

as Title 24, as its state energy code. Of the building designs considered in this study, the 

requirements in ASHRAE 90.1-2007 most closely compare to Title 24. States that have 

not yet adopted a state energy code are assumed to meet ASHRAE 90.1-1999 building 

energy efficiency requirements. A “Low Energy Case” design based on ASHRAE 

189.1-2009, which goes beyond ASHRAE 90.1-2007, is included as an additional 

building design alternative. 

Table 2-2 shows the variation in commercial building energy codes across the thirteen 

states in the West Census Region.4 This study uses the status of state energy codes as of 

December 2011, at which point the BIRDS database was constructed. Three states 

currently do not have a statewide energy code while one state, two states, and seven 

states have adopted ASHRAE 90.1-2001, ASHRAE 90.1-2004, and ASHRAE 90.1-2007, 

respectively. Three cities in Arizona (Flagstaff, Phoenix, and Tucson) and one city in 

Colorado (Grand Junction) have adopted a newer edition of ASHRAE 90.1 than has the 

state in which it is located. 

3 California is assumed to have adopted ASHRAE 90.1-2007 because California has adopted Title 24 as its
 

state energy code, which is similar but the same as ASHRAE 90.1-2007.
 4 Since the publication of Kneifel (2011b) and Kneifel (2012), the BIRDS database has been updated to
 

include subsequent changes in state energy codes through December 2011.
 

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Study Design 

Table 2-2 Energy Code by State/City for the West Census Region5 

State	 City Zone Code State City Zone Code State City Zone Code 

AK Anchorage	 Alamosa 2001 Elko 5B 2004 7 None CO 6A NV 

Barrow 8 None Boulder 5A 2001 Ely 5B 2004 

Fairbanks 8 None Colorado Springs 5A 2001 Las Vegas 3B 2004 

Juneau 7 None Eagle 6A 2001 Reno 5B 2004 

Kodiak 7 None Grand Junction 5A 2004 Tonopah 5B 2004 

Nome 8	 None Pueblo 5A 2001 Winnemucca 5B 2004 

AZ	 Flagstaff 5B 2004 HI Hilo 1 2004 OR Astoria 4C 2007 

Phoenix 2B 2004 Honolulu 1 2004 Burns 5B 2007 

Prescott 4B None ID Boise 5A 2007 Eugene 4C 2007 

Tucson 2B 2004 Lewiston 5A 2007 Medford 4C 2007 

Winslow 5B None Pocatello 6A 2007 North Bend 4C 2007 

Yuma 2B None MT Billings 6B 2007 Pendleton 5B 2007 

CA Arcata 4B 2007 Cut Bank 6B 2007 Portland 4C 2007 

Bakersfield 3B 2007 Glasgow 6B 2007 Redmond 5B 2007 

Daggett 3B 2007 Great Falls 6B 2007 Salem 4C 2007 

Fresno 3B 2007 Helena 6B 2007 UT Cedar City 5B 2007 

Long Beach 3B 2007 Kalispell 6B 2007 Salt Lake City 5B 2007 

Los Angeles 3B 2007 Lewistown 6B 2007 WA Olympia 4C 2007 

Riverside 3B 2007 Miles City 6B 2007 Quillayute 4C 2007 

Sacramento 3B 2007 Missoula 6B 2007 Seattle 4C 2007 

San Diego 3B 2007 NM Albuquerque 4B 2007 Spokane 5B 2007 

San Francisco 3C 2007 Roswell 3B 2007 Yakima 5B 2007 

Santa Maria 3C 2007 Tucumcari 4B 2007 WY Casper 6B None 

Cheyenne 6B None 

Lander 6B None 

Rock Springs 6B None 

Sheridan 6B None 

The thirteen states, 73 cities, and 8 ASHRAE climate zones listed in Table 2-2 are shown 

in Figure 2-1. Larger states and states with more significant population centers have more 

cities included in the BIRDS database. For example, California has eleven cities while 

Utah has two cities. The climate zone(s) for each state vary across the West Census 

Region from ASHRAE Climate Zone 1 in Hawaii to Zone 7 and Zone 8 in Alaska. The 

entire region is located in the “dry” (B) and “marine” (C) subzones. 

5 State energy codes as of December 2011. 

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Study Design 

Figure 2-1 Cities and Climate Zones 

2.3 Study Period Lengths 

Nine study period lengths are chosen for this analysis: 1 year, 5 years, 10 years, 15 years, 

20 years, 25 years, 30 years, 35 years, and 40 years. The wide variation in investment 

time horizons allows this report to analyze the impact the study period length has on the 

benefits and costs of more stringent state energy code adoption. A 1-year study period is 

more representative of a developer that intends to sell a property soon after it is 

constructed. A 5-year to 15-year study period more closely represents a building owner’s 

time horizon because few owners are concerned about costs realized beyond a decade 

into the future. The 20-year to 40-year study periods better represents institutions, such as 

colleges or government agencies, because these entities will own or lease buildings for 

20 or more years. Most of the analysis in this study uses a 10-year study period. 

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Cost Data 

3 Cost Data 

The cost data collected to estimate life-cycle costs for the BIRDS database originates 

from multiple sources, including RS Means databases (RS Means, 2009), Whitestone 

(2008), and the U.S. Energy Information Administration (EIA) (EIA, 2010).6 Costs are 

grouped into two categories, first costs that include initial building construction costs and 

future costs that include operational costs, maintenance, repair, and replacement costs, 

and building residual value. Both of these cost categories are described below. 

3.1 First Costs 

Building construction costs are obtained from the RS Means CostWorks online databases 

(RS Means, 2009). The costs of a prototypical building are estimated by the RS Means 

CostWorks Square Foot Estimator to obtain the default costs for each building type for 

each component. The RS Means default building is the baseline used to create a building 

that is compliant with each of the five energy efficiency design alternatives: ASHRAE 

90.1-1999, ASHRAE 90.1-2001, ASHRAE 90.1-2004, ASHRAE 90.1-2007, and the higher 

efficiency “Low Energy Case" (LEC) design. The RS Means default buildings are 

adapted to match the five prototype building designs by using the RS Means CostWorks 

Cost Books databases. 

Five components -- roof insulation, wall insulation, windows, lighting, and HVAC 

efficiency -- are changed to make the prototypical designs ASHRAE 

90.1-1999, -2001, -2004, and -2007 compliant. A summary of the minimum requirement 

ranges, excluding HVAC efficiency, for each building design are shown in Table 3-1. 

The windows are selected to meet the minimum window characteristics (U-factor, solar 

heat gain coefficient (SHGC), and visible transmittance (VT)) required by the building 

design at the lowest possible cost. The lighting density in watts per unit of conditioned 

floor area is adjusted to meet each standard edition’s requirements. 

6 See Kneifel (2012) for additional details of the cost data used in the BIRDS database. 

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Cost Data 

Table 3-1 Energy Efficiency Component Requirements for Alternative Building 

Designs 

Design ASHRAE ASHRAE ASHRAE ASHRAE Low Energy 

Component Parameter Units 90.1-1999 90.1-2001 90.1-2004 90.1-2007 Case* 

Roof 

Insulation R-Value m 2

∙K/W 

(ft2

∙°F∙h/Btu) 

1.7 to 4.4 

(10.0 to 25.0) 

1.7 to 4.4 

(10.0 to 25.0) 

2.6 to 3.5 

(15.0 to 20.0) 

2.6 to 3.5 

(15.0 to 20.0) 

4.4 to 6.2 

(25.0 to 35.0) 

Wall 

Insulation R-Value m 2

*K/W 

(ft2

∙°F∙h/Btu) 

0.0 to 3.8 

(0.0 to 21.6) 

0.0 to 3.8 

(0.0 to 21.6) 

0.0 to 2.7 

(0.0 to 15.2) 

0.0 to 2.7 

(0.0 to 15.2) 

0.7 to 5.5 

(3.8 to 31.3) 

Windows U-Factor W/(m2∙K) 

(Btu/(h∙ft2

∙°F)) 

1.42 to 7.21 

(0.25 to 1.27) 

1.42 to 7.21 

(0.25 to 1.27) 

1.99 to 6.47 

(0.35 to 1.14) 

2.50 to 6.47 

(0.44 to 1.14) 

1.97 to 6.42 

(0.35 to 1.13) 

SHGC Fraction 0.14 to NR† 0.14 to NR† 0.17 to NR† 0.25 to NR 0.25 to 0.47 

Lighting Power 

Density W/m2 (W/ft2

) 14.0 to 20.5 

(1.3 to 1.9) 

14.0 to 20.5 

(1.3 to 1.9) 

10.8 to 16.1 

(1.0 to 1.5) 

10.8 to 16.1 (1.0 

to 1.5) 

8.6 to 16.1 

(0.8 to 1.5) 

Overhangs None None None None Zones 1 to 5 

Daylighting None None None None Zones 1 to 8 

†North facing SHGC requirements are less restrictive than the requirements for the other 3 orientations. 

* Low Energy Case design requirements are taken from the EnergyPlus simulations. 

NR = No Requirement for one or more climate zones. The value of SHGC cannot exceed 1.0. 

The LEC design increases the thermal efficiency of insulation and windows beyond 

ASHRAE 90.1-2007, further reduces the lighting power density, and adds daylighting and 

window overhangs. The lighting density of the lighting system is decreased by first 

increasing the efficiency of the lighting system and then decreasing the number of 

fixtures in the lighting system.7 Daylighting is included for all building types and climate 

zones. Overhangs are placed on the east, west, and south sides of the building for each 

floor in Climate Zone 1 through Climate Zone 5 because these warmer climates are the 

zones that benefit from blocking solar radiation.8 

Table 3-2 summarizes the HVAC efficiency requirements for each building design option 

across the different types of HVAC equipment.9 Note that the LEC design assumes the 

same equipment efficiencies as ASHRAE 90.1-2007. This study assumes that cooling 

equipment is run on electricity while heating equipment is run on natural gas. The most 

significant increases in HVAC efficiency requirements occur between ASHRAE 

90.1-1999 and ASHRAE 90.1-2001 except for rooftop packaged units, which have 

consistently increasing requirements across the ASHRAE 90.1 Standard editions. 

7 First, incandescent lighting is replaced with compact fluorescent lighting while typical T-12 fluorescent 

tube lighting is replaced with more efficient T-8 fluorescent tube lighting to decrease the lighting density of 

the lighting system. Second, the number of fixtures is reduced to meet the remainder of the required 

reduction in watts per unit of floor area. Increasing the efficiency of the lighting increases the costs of 

construction. The first approach increases first costs while the second approach decreases first costs for the 

lighting system. This approach is based on Belzer et al. (2005) and Halverson et al. (2006). 

8 Overhang cost source is Winiarski et al. (2003) 

9 This study does not account for new HVAC efficiency requirements set by federal regulations. 

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Cost Data 

Table 3-2 HVAC Energy Efficiency Requirements for Alternative Building Designs
 

HVAC Equipment Type Unit ASHRAE ASHRAE ASHRAE ASHRAE Low Energy 

Type 90.1-1999 90.1-2001 90.1-2004 90.1-2007 Case 

Cooling Rooftop Packaged Unit EER 8.2 to 9.0 9.0 to 9.9 9.2 to 10.1 9.5 to 13.0 9.5 to 13.0 

Air-Cooled Chiller COP 2.5 to 2.7 2.8 2.8 2.8 2.8 

Water-Cooled Chiller COP 3.80 to 5.20 4.45 to 5.50 4.45 to 5.50 4.45 to 5.50 4.45 to 5.50 

Split System with EER 8.7 to 9.9 9.9 to 10.1 10.1 10.1 10.1 

Condensing Unit 

Heating Hot Water Boiler Et 75 % to 80 % 75 % to 80 % 75 % to 80 % 75 % to 80 % 75 % to 80 % 

Furnace Et 80 % 75 % to 80 % 75 % to 80 % 75 % to 80 % 75 % to 80 % 

Assume that Ec = 75% Et and AFUE = Et, where Ec = combustion efficiency; Et = thermal efficiency; AFUE = Annual Fuel 

Utilization Efficiency 

EER = Energy Efficiency Ratio 

COP = Coefficient of Performance 

Note: Efficiency requirement ranges are based only on the system sizes calculated in the whole building energy simulations. 

The HVAC system size varies across the five building designs because changing the 

thermal characteristics of the building envelope alters the heating and cooling loads of the 

building. The EnergyPlus whole building energy simulations “autosize” the HVAC 

system to determine the appropriate system size to efficiently maintain the thermal 

comfort while dealing with ventilation requirements.10 For each building design, the 

HVAC cost for the default HVAC system is replaced with the cost of the “autosized” 

HVAC system. An HVAC efficiency cost multiplier is used to adjust the HVAC 

equipment costs in accordance with the standard efficiency requirements shown in Table 

3-2. 

Construction costs for a building in each location are estimated by summing the baseline 

costs for the RS Means default building and the changes in costs required to meet the 

alternative prototype designs. National average construction costs are adjusted with the 

2009 RS Means CostWorks City Indexes to control for local material and labor price 

variations. The “weighted average” city construction cost index is used to adjust the costs 

for the baseline default building while “component” city indexes are used to adjust the 

costs for the design changes. Once the indexed construction cost of the building is 

calculated, it is multiplied by the contractor “mark-up” rate, 25 %, and architectural fees 

rate, 7 %, to estimate the building's “first costs” of construction for the prototype 

buildings. These rates are the default values used by the RSMeans Square Foot 

Estimator. 

10 For more detail about the ventilation requirements are see Kneifel (2011b). 

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Cost Data 

3.2 Future Costs 

Component and building lifetimes and component repair requirements are based on data 

from Whitestone (2008). Building service lifetimes are assumed constant across climate 

zones: apartment buildings lasting for 65 years; dormitories for 44 years; and hotels, 

schools, office buildings, retail stores, and restaurants for 41 years. 

Building component maintenance, repair, and replacement (MRR) rates are from Kneifel 

(2010) and Kneifel (2011a). Insulation and windows are assumed to have a lifespan 

greater than 40 years and have no maintenance requirements. Insulation is assumed to 

have no repair costs. Windows have an assumed annual repair cost equal to replacing 1 % 

of all window panes, with costs that vary depending on the required window 

specifications (RS Means, 2009). The heating and cooling units have different lifespans 

and repair rates based on climate, ranging from 4 to 33 years for repairs and 13 to 50 

years for replacements. 

MRR cost data are collected from two sources. The total maintenance and repair costs per 

square foot of conditioned floor area (minus the HVAC maintenance and repair costs) 

represent the baseline MRR costs per unit of floor area, which occur for a building type 

regardless of the energy efficiency measures incorporated into the design. These data are 

collected from Whitestone (2008), which reports average maintenance and repair costs 

per unit of floor area by building component for each year of service life for each 

building type. The building types in Whitestone do not match exactly to the 11 building 

types selected for this study, and the most comparable profile is selected. 

RS Means CostWorks is the source of MRR costs for the individual components for 

which MRR costs change across alternative building designs, which in this analysis are 

the HVAC system, lighting system, and windows. Lighting systems, including 

daylighting controls for the LEC design, are assumed to be replaced every 20 years. The 

HVAC system size varies based on the thermal performance of the alternative building 

design, which results in varying MRR costs because smaller systems are relatively 

cheaper to maintain, repair, and replace. 

Future MRR costs are discounted to equivalent present values using the Single Present 

Value (SPV) factors for future non-fuel costs reported in Rushing and Lippiatt (2008), 

which are calculated using the U.S. Department of Energy's 2008 real discount rate for 

energy conservation projects (3 %). 

A building's residual value is its value at the end of the study period. It is estimated in 

three parts, for the building (excluding components replaced during the study period), the 

HVAC system, and the lighting system based on the approach defined in Fuller et al. 

(1996). The building's residual value is assumed to be equal to the building's first cost 

(minus any components replaced over the study period) multiplied by the ratio of the 

12
 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Cost Data 

study period to the service life of the building, and discounted from the end of the study 

period. 

Two components may be replaced during the study period, the lighting and HVAC 

systems. Residual values for these components are computed for each location in a 

similar manner to the building residual value. The remaining “life” of the component is 

determined by taking its service life minus the number of years since its last installation, 

whether it occurred during building construction or replacement. The ratio of remaining 

life to service life is multiplied by the installed cost of the lighting and HVAC systems, 

and discounted from the end of the study period. The lighting system service life is 20 

years while the HVAC system service life varies by location based on Towers et al. 

(2008). 

Annual energy costs are estimated by multiplying annual electricity and natural gas use 

predicted by the whole building energy simulation by the average state retail commercial 

electricity and natural gas prices, respectively. Average state commercial electricity and 

natural gas prices for 2009 are collected from the Energy Information Administration 

(EIA) Electric Power Annual State Data Tables (EIA, 2010a) and Natural Gas Navigator 

(EIA, 2010b), respectively. The electricity and natural gas prices are assumed to change 

over time according to EIA forecasts from 2009 to 2039. These forecasts are embodied in 

the Federal Energy Management Program (FEMP) Uniform Present Value Discount 

Factors for energy price estimates (UPV*) reported in Rushing and Lippiatt (2009).11 The 

UPV* values are used to discount future energy costs to equivalent present values. The 

discount factors vary by Census region, building sector, and fuel type. 

11 The escalation rates for years 31-40 are assumed to be the same as for year 30. 

13
 
Cost Data 

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Building Stock Data 

4 Building Stock Data 

Aggregating the savings for individual newly constructed commercial buildings to the 

state level requires new construction data for each building type within each state. This 

study uses the commercial building weighting factors reported in Jarnagin and 

Bandyopadhyay (2010) to estimate the total energy use savings, energy cost savings, lifecycle cost savings, and carbon emissions reduction resulting from adopting newer energy 

standard editions for each state. Jarnagin and Bandyopadhyay (2010) use two databases 

to generate the commercial building weighting factors: the 2003 Commercial Buildings 

Energy Consumption Survey (CBECS) and a McGraw-Hill construction dataset. The 

databases and the resulting weighting factors are described below. 

4.1 Databases 

The Commercial Buildings Energy Consumption Survey (CBECS) is a sample survey 

that collects information on the existing stock of U.S. commercial buildings. The sample 

includes 5215 buildings across the U.S. and 14 building type categories: education, food 

sales, food service, health care, lodging, mercantile, office, public assembly, public order 

and safety, religious worship, service, warehouse and storage, other, and vacant. Each 

category includes up to 12 subcategories as shown in Table A-1 in Appendix A. The 

survey data do not report the age or specific location of the building to protect the 

confidentiality of the respondents. 

The McGraw-Hill dataset includes data for all new commercial buildings and additions, 

over 254 000 records and 761.8 million m2 (8.2 billion ft2

) of new construction, for 2003 

through 2007. The data are more detailed than the CBECS data, and include year of 

construction and location. 

4.2 Weighting Factors 

Jarnagin and Bandyopadhyay (2010) maps the more detailed McGraw-Hill dataset to the 

CBECS categories and subcategories shown in Table 4-1. The prototype commercial 

buildings analyzed in this study, shown in bold, represent 48.7 % of new commercial 

building stock floor area for 2003 through 2007 for the West Census Region. The 

McGraw-Hill dataset is aggregated at the CBECS category-level. For this study, a 

prototype building is assumed to represent its entire CBECS category, which implies the 

prototypes together represent 58.1 % of the new commercial building stock. 

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2007)

Building Stock Data 

Table 4-1 New Commercial Building Construction (West, 2003 through 2007) 

Category Subcategory 

Conditioned Floor 

Area 

1000 m2 (1000 ft2

) 

Percentage in 

Category 

Percentage 

of Total 

Office Large 5261 (56 631) 22.2 % 2.9 % 

Office Medium 9574 (103 058) 40.4 % 5.3 % 

Office Small 8863 (95 405) 37.4 % 4.9 % 

Retail 20 747 (223 319) 72.9 % 11.5 % 

Strip Mall 7713 (83 017) 27.1 % 4.3 % 

School Primary 5815 (62 593) 32.5 % 3.2 % 

School Secondary 12 077 (130 001) 67.5 % 6.7 % 

Hospital 4558 (49 062) 44.1 % 2.5 % 

Other Health Care 5778 (62 190) 55.9 % 3.2 % 

Restaurant Sit Down 830 (8931) 52.9 % 0.5 % 

Restaurant Fast Food 739 (7951) 47.1 % 0.4 % 

Hotel Large 8030 (86 436) 74.2 % 4.4 % 

Hotel/Motel Small 2792 (30 055) 25.8 % 1.5 % 

Warehouse 25 644 (276 029) 14.2 % 

Public Assembly 8835 (95 100) 4.9 % 

Apartment High-rise 12 477 (134 305) 55.1 % 6.9 % 

Apartment Mid-rise 10 168 (109 443) 44.9 % 5.6 % 

No Prototype 30 821 (331 759) 17.1 % 

Total (2003 to 180 722 (1 945 278) 100.0 % 

Note: Subcategory weighting is based on national construction data. 

The types and floor area of buildings being constructed vary across states. Table A-2 and 

Table A-3 in Appendix A report new building construction for 2003 through 2007 by 

building type and state, in total new floor area and percentage of new floor area, 

respectively. The data in Table A-2 are used to aggregate the total savings for the new 

construction in the CBECS categories represented by the prototype building analyzed in 

this study. Nine of the eleven prototype commercial buildings analyzed in this study are 

covered by data reported in Table 4-1. No data for dormitories are reported, which limites 

the ability to estimate statewide impacts for the two types of dormitories. 

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Analysis Approach 

5 Analysis Approach 

The analysis in this report compares benefits and costs of the current state energy codes 

to more stringent alternatives. The relative changes in energy use, energy costs, energyrelated carbon emissions, and life-cycle costs use the current energy code for a state as 

the baseline and uses each ASHRAE 90.1 Standard edition that is newer than that 

required by the current state energy code as an alternative design. The results are 

considered on both a percentage change and an aggregate change basis. 

5.1 Energy Use 

The analysis uses each state’s current energy code as the baseline energy efficiency 

design. For any state without a state energy code, ASHRAE 90.1-1999 is assumed to be 

the baseline because it represents minimum energy-related industry practices. The 

baseline for each state is compared to the higher energy efficiency building designs to 

determine the relative annual energy use savings resulting from adopting a more recent 

standard edition as the state’s energy code. For example, if a state’s energy code has 

adopted ASHRAE 90.1-2001 as its energy standard requirement, this baseline energy use 

is compared to the energy use of all newer energy standard editions, ASHRAE 90.1-2004 

and ASHRAE 90.1-2007, as well as a “Low Energy Case” that increases building energy 

efficiency beyond ASHRAE 90.1-2007. 

It is assumed that the building maintains its energy efficiency performance throughout the 

study period, resulting in energy consumption remaining constant over the entire study 

period. This assumption is justified by the maintenance, repair, and replacement costs 

included in the analysis to ensure the building and its equipment performs as expected. 

5.2 Life-Cycle Costing 

Life-cycle costing (LCC) takes into account all relevant costs throughout the chosen 

study period, including construction costs, maintenance, repair, and replacement costs, 

energy costs, and residual values. A cost’s present value (PV) is calculated by 

discounting its nominal value into today’s dollars based on the year the cost occurs and 

the assumed discount rate. LCC of buildings typically compares the costs for a baseline 

building design to the costs for alternative, more energy-efficient building designs to 

determine if future operational savings justify higher initial investments.12 For this study, 

the design based on any ASHRAE 90.1 Standard edition that is newer than the standard 

edition required by the current state energy code is compared to the baseline state energy 

code compliant design to determine the changes in life-cycle costs. 

12 All life-cycle cost calculations are based on ASTM Standards of Building Economics (2012). 

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Analysis Approach 

Two metrics are used to analyze changes in life-cycle costs: net LCC savings and net 

LCC savings as a percentage of base case LCC. Net LCC savings is the difference 

between the base case and alternative design's LCCs. 

5.3 Carbon Assessment 

The BIRDS database expands on Kneifel (2011a) by conducting a life-cycle assessment 

(LCA) of energy-related greenhouse gas emissions, following guidance in the 

International Organization for Standardization (ISO) 14040 series of standards for LCA. 

The analysis quantifies the greenhouse gas emissions from electricity and natural gas use 

on a cradle-to-grave basis, including emissions from raw materials acquisition, materials 

processing, generation, transmission, distribution, use, and end-of-life. 

The assessment of cradle-to-grave energy-related carbon emissions considers a number of 

greenhouse gases for two types of energy consumption, electricity and natural gas. 

Carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O) are the most prevalent. 

While carbon emissions from natural gas use can be assessed on a national average basis, 

those from electricity use are highly dependent upon the fuel mixes of regional electricity 

grids. For this reason, electricity emissions are assessed at the state-level using North 

American Electric Reliability Corporation (NERC) sub-region level data.13 The life-cycle 

data sets for natural gas production and combustion as well as for all fuel sources in the 

electricity grid come from the U.S. Life-Cycle Inventory (LCI) database (LCI, 2012). The 

state-level average emissions rates per GWh (GBtu) of electricity generated are obtained 

from the 2007 Emissions and Generation Resource Integrated Database (eGRID2007), 

which is a collection of data from the EIA, the Federal Energy Regulatory Commission 

(FERC), and the Environmental Protection Agency (EPA). 14 Table A-4 in Appendix A 

shows variation in the emissions rates for the top three greenhouse gases by state, which 

results from differing fuel mixes used for electricity generation in a state.15 

These greenhouse gas emissions are converted into a common unit of measure called 

carbon dioxide equivalents (CO2e) using equivalency factors reported in Table 5-1, which 

represent the global warming potential (GWP) of one unit of greenhouse gas relative to 

that of the same amount of carbon dioxide. For example, one unit of methane has 25 

times the GWP as the same amount of carbon dioxide, and nitrous oxide has 298 times 

the GWP as carbon dioxide. The aggregated CO2e is calculated by taking the amount of 

13 For states located in more than one NERC sub-region, a weighted average of emissions rates for the 

multiple sub-regions is implemented. 

14 Emissions rates are held constant over all study periods. A significant change in the fuel mix of 

electricity in an NERC subregion would impact the estimated impacts on carbon emissions. 

15 While carbon assessment of building construction, maintenance, repair, and replacement is currently 

excluded from the analysis, it is currently under development and will be included in future analysis of this 

work. 

18
 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Analysis Approach 

each flow multiplied by its CO2e factor, and summing the resulting CO2 equivalencies. 

The results are analyzed in metric tons of CO2e emissions, and will be referred to as 

“carbon emissions” for the remainder of the report. 

Table 5-1 Greenhouse Gas Global Warming Potentials 

Environmental Flow GWP (CO2e) 

Carbon Dioxide (CO2) 1 

Methane (CH4) 25 

Nitrous Oxide (N2O) 298 

Ethane, 1,1-difluoro-, HFC-152a 124 

Ethane, 1,1,1-trichloro-, HCFC-140 146 

Ethane, 1,1,1,2-tetrafluoro-, HFC-134a 1430 

Ethane, 1,1,2-trichloro-1,2,2-trifluoro-, CFC-113 6130 

Ethane, 1,2-dichloro-1,1,2,2-tetrafluoro-, CFC-114 10 000 

Ethane, hexafluoro-, HFC-116 12 200 

Methane, bromo-, Halon 1001 5 

Methane, bromochlorodifluoro-, Halon 1211 1890 

Methane, bromotrifluoro-, Halon 1301 7140 

Methane, chlorodifluoro-, HCFC-22 1810 

Methane, dichloro-, HCC-30 9 

Methane, dichlorodifluoro-, CFC-12 10 900 

Methane, monochloro-, R-40 13 

Methane, tetrachloro-, CFC-10 1400 

Methane, tetrafluoro-, CFC-14 7390 

Methane, trichlorofluoro-, CFC-11 4750 

Methane, trifluoro-, HFC-23 14 800 

5.4 Analysis Metrics 

The average percentage energy use savings, energy cost savings, energy-related carbon 

emissions reductions, and life-cycle cost savings are calculated by taking the simple 

average of the percentage savings for each location-building type combination in the state 

or nation. The average of the percentage change is used instead of using the average 

change in total values for the state or nation because the latter approach would in effect 

give greater weight to buildings or locations with greater total changes. The simple 

average approach used in this study weights each location-building type equally. 

The estimated change in total energy use, energy costs, energy-related carbon emissions, 

and life-cycle costs for each of the building types is combined with new commercial 

building construction data to calculate the magnitude of the available total savings a state 

may realize if it were to adopt a more energy efficient standard as its state energy code. 

The total change per unit of floor area is multiplied by the average annual floor area of 

19
 
 

 

 

 

 

 

 

 

Analysis Approach 

new construction for 2003 to 2007, discussed in Section 4.2, which results in the total 

savings over the study period for a single year’s worth of new construction in a state. 

In order to compare total savings across states for a 10-year study period, the aggregate 

savings in energy use and life-cycle costs are divided by the annual new floor area. 

Aggregate savings in energy costs and energy-related carbon emissions are divided by 

aggregate savings in energy use for a 10-year study period to create a comparable metric 

to determine the factors that impact the relative savings across states. 

20
 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

6 

Alaska 

Alaska 

Alaska is located in the Pacific Census Division and spans two climate zones (Zone 7 and 

Zone 8). The state does not have a commercial building energy code, and is assumed to 

build to the current minimum industry practices represented by ASHRAE 90.1-1999 

requirements. Table 6-1 provides an overview of Alaska’s simulated energy use keyed to 

building types and energy standard editions. Average energy use varies across building 

types and building designs. The 8-story office building uses the least amount of energy at 

113 kWh/m2 to 140 kWh/m2 (36 kBtu/ft2 to 44 kBtu/ft2

) annually. The high school uses 

the greatest amount of energy at 448 kWh/m2 to 480 kWh/m2 (142 kBtu/ft2 to 

152 kBtu/ft2) annually. 

Table 6-1 Average Annual Energy Use by Building Type and Energy Standard 

Edition, Alaska 

Building 

Type 

Standard Edition 

1999 

kWh/m2 kBtu/ft2 

2001 

kWh/m2 kBtu/ft2 

2004 

kWh/m2 kBtu/ft2 

2007 

kWh/m2 kBtu/ft2 

LEC 

kWh/m2 kBtu/ft2 

APART04 

APART06 

270 86 

265 84 

270 86 

265 84 

269 85 

264 84 

258 82 

253 80 

239 76 

236 75 

DORMI04 

DORMI06 

228 72 

286 91 

228 72 

286 91 

231 73 

288 91 

218 69 

275 87 

192 61 

258 82 

HOTEL15 263 84 263 83 263 84 276 87 250 79 

HIGHS02 480 152 480 152 481 153 473 150 448 142 

OFFIC03 

OFFIC08 

OFFIC16 

171 54 

140 44 

223 71 

171 54 

139 44 

222 70 

172 55 

137 44 

223 71 

162 51 

134 43 

236 75 

131 42 

113 36 

209 66 

RETAIL1 219 70 219 69 221 70 207 66 166 53 

RSTRNT1 286 91 285 90 291 92 257 82 197 63 

The detailed analysis for this state reports the changes in energy use, energy costs, 

energy-related carbon emissions, and life-cycle costs from adoption of increasingly 

stringent energy standard editions. The results are reported in terms of average 

percentage savings on a statewide and city-by-city basis and as total savings on a 

statewide basis. 

6.1 Percentage Savings 

Changes in percentage terms allow for direct comparisons across building types and 

locations within a state. This section discusses the average percentage changes from 

investing in more energy efficient designs for the state of Alaska. 

21
 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Alaska 

6.1.1 Energy Use 

Table 6-2 shows the percentage changes in energy use for Alaska. There is minimal 

change in energy use from adopting ASHRAE 90.1-2001 relative to ASHRAE 90.1-1999 

with all 11 building types having reductions in energy use of 0.7 % or less. There is a 

small decrease in energy use for 9 of 11 building types for ASHRAE 90.1-2004, with the 

percentage change in energy use ranging from 0.6 % to -3.4 % with an average of -0.8 %. 

The average change in energy use from constructing buildings using ASHRAE 90.1-2007 

requirements ranges from 4.0 % to -12.4 %, with an overall average of -4.8 %. 

Table 6-2 Average Percentage Change in Energy Use from Adoption of Newer 

Standard Editions, Alaska 

Building Standard Edition
 

Type
 2001 2004 2007 LEC 

APART04 -0.1 -1.2 -5.6 -12.7 

APART06 -0.1 -1.3 -5.5 -12.2 

DORMI04 -0.2 0.2 -6.5 -18.1 

DORMI06 -0.1 -0.2 -5.1 -11.1 

HOTEL15 -0.2 -1.0 2.7 -6.9 

HIGHS02 -0.0 -0.2 -2.4 -7.7 

OFFIC03 -0.4 -1.0 -8.0 -25.5 

OFFIC08 -0.7 -3.4 -6.0 -21.3 

OFFIC16 -0.3 -0.7 4.0 -8.1 

RETAIL1 -0.1 -0.5 -8.4 -26.3 

RSTRNT1 -0.3 0.6 -12.4 -33.4 

Average -0.2 -0.8 -4.8 -16.7 

The ASHRAE 90.1-2004 and ASHRAE 90.1-2007 designs realize an increase for some 

building types. The key driver is the consolidation of the 26 climate zones in ASHRAE 

90.1-2001 down to 8 climate zones in ASHRAE 90.1-2004 and ASHRAE 90.1-2007, 

which resulted in changes in building envelope requirements for some locations in the 

state, including relaxation of the maximum window U-factor requirement and insulation 

R-value minimum requirements. Given the cold climate in Alaska, the relaxation of these 

requirements leads to increases in natural gas consumption. 

For the high-rise, 100 % glazed buildings (16-story office building and 15-story hotel), 

ASHRAE 90.1-2004 is actually more energy efficient than ASHRAE 90.1-2007 because 

the maximum window SHGC in Zone 7 and Zone 8 is decreased from ASHRAE 

90.1-2004 to ASHRAE 90.1-2007, making the requirement stricter. Buildings in colder 

climates benefit from additional solar heat gains. The 100 % glazing amplifies the lost 

heat gain from the lower SHGC, which increases natural gas consumption enough to 

overwhelm the energy efficiency gains obtained from other measures that decrease 

energy consumption, such as increased roof insulation R-values. 

22
 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Alaska 

The LEC design realizes the greatest reductions in energy use, with the change in energy 

use relative to ASHRAE 90.1-1999 ranging from -6.9 % to -33.4 % with an average 

of -16.7 %. Similar to the ASHRAE 90.1-2007 design, the lowest reduction in energy use 

for the LEC design occurs in the buildings with the greatest window-to-wall ratios due to 

the stricter window SHGC requirement. 

6.1.2 Energy Costs 

Table 6-3 shows minimal change in energy costs over 10 years from adopting ASHRAE 

90.1-2001 (-0.1 % to -1.0 %), which mirrors the energy use results described above. 

There is a significant variation in the percentage change in average energy costs for 

ASHRAE 90.1-2004, ranging from -5.6 % to -18.0 % depending on the building type, 

with an average of -12.7 %. The average change in energy costs from constructing 

buildings using ASHRAE 90.1-2007 requirements ranges from -3.2 % to -21.1 %, with an 

overall average of -14.3 %. The LEC design realizes the greatest change in energy costs, 

with the average change by building type ranging from -14.9 % to -40.1 % with an 

average of -27.6 % overall. 

Table 6-3 Average Percentage Change in Energy Costs, 10-Year, Alaska 

Building Standard Edition 

Type 2001 2004 2007 LEC 

APART04 -0.1 -17.8 -20.2 -31.2 

APART06 -0.1 -18.0 -20.3 -31.1 

DORMI04 -0.4 -17.8 -21.1 -34.8 

DORMI06 -0.2 -17.1 -19.9 -30.0 

HOTEL15 -0.4 -16.2 -12.9 -23.5 

HIGHS02 -0.1 -5.6 -7.1 -17.8 

OFFIC03 -0.6 -8.1 -10.6 -27.6 

OFFIC08 -1.0 -9.9 -10.8 -25.8 

OFFIC16 -0.6 -6.9 -3.2 -14.9 

RETAIL1 -0.2 -10.8 -13.9 -27.3 

RSTRNT1 -0.6 -11.1 -17.0 -40.1 

Average -0.4 -12.7 -14.3 -27.6 

For all building designs, the reductions in energy costs are greater than the reductions in 

energy use because the percentage reduction in electricity consumption is greater than the 

reduction in natural gas consumption. In the most extreme cases, electricity consumption 

is decreased while natural gas consumption is increased. The buildings use electricity for 

all energy consumption except for the heating component of the HVAC system, which 

uses natural gas. The energy efficiency measures adopted may lead to a decrease in 

energy use for both lighting and cooling the building while increasing heating loads. 

Since electricity is more expensive than natural gas on a per unit of energy basis, the shift 

in energy use from cooling to heating magnifies the decrease in energy costs for the 

building. 

23
 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Alaska 

6.1.3 Energy-related Carbon Emissions 

Minimal changes in energy use lead to small changes (less than 1 %) in cradle-to-grave 

energy-related carbon emissions for the ASHRAE 90.1-2001 design across all building 

types. Table 6-4 shows a significant change in average energy-related carbon emissions 

for ASHRAE 90.1-2004 for all building types, ranging from -3.6 % to -12.5 % with an 

average of -8.9 %. The ASHRAE 90.1-2007 design leads to slightly greater reductions 

than ASHRAE 90.1-2004, with the average change in carbon emissions ranging 

from -1.0 % to -16.3 % with an overall average of -11.1 %. The LEC design leads to the 

greatest average carbon emissions changes, ranging from -12.9 % to -37.9 % depending 

on the building type with an average of -24.0 % across all building types. 

Table 6-4 Average Percentage Change in Energy-related Carbon Emissions, 10­

Year, Alaska 

Building Standard Edition 

Type 2001 2004 2007 LEC 

APART04 -0.1 -12.2 -15.3 -25.0 

APART06 -0.1 -12.5 -15.4 -24.8 

DORMI04 -0.3 -12.0 -16.3 -29.3 

DORMI06 -0.1 -11.4 -14.9 -23.7 

HOTEL15 -0.3 -11.2 -7.7 -18.0 

HIGHS02 -0.1 -3.6 -5.3 -14.0 

OFFIC03 -0.5 -6.0 -9.7 -26.9 

OFFIC08 -0.9 -8.2 -9.5 -24.6 

OFFIC16 -0.5 -5.1 -1.0 -12.9 

RETAIL1 -0.1 -7.7 -12.1 -26.8 

RSTRNT1 -0.5 -7.5 -15.4 -37.9 

Average -0.3 -8.9 -11.1 -24.0 

As would be expected, a more energy efficient building design results in greater 

reductions in carbon emissions. Similar to energy costs, the percentage changes in carbon 

emissions are greater than the percentage changes in energy use because the energy 

efficiency measures decrease electricity consumption by a greater percentage than natural 

gas consumption. The greater relative reduction in electricity consumption further 

decreases carbon emissions because electricity has a higher carbon emissions rate per unit 

of energy than natural gas in Alaska. 

6.1.4 Life-Cycle Costs 

The most cost-effective building design for each building type is bolded in Table 6-5. 

Life-cycle costs increase for the ASHRAE 90.1-2001 design compared to ASHRAE 

90.1-1999 for all building types over a 10-year study period. ASHRAE 90.1-1999 is the 

lowest cost building design for one building type while ASHRAE 90.1-2004 and ASHRAE 

90.1-2007 are the lowest cost building design for two and four building types, 

24
 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Alaska 

respectively. The change in life-cycle costs for ASHRAE 90.1-2004 and -2007 range 

from -2.6 % to 2.7 % depending on building type. The LEC design realizes a reduction in 

life-cycle costs for 10 of 11 building types, with the percentage change in life-cycle costs 

ranging from -2.4 % to 1.0 %. 

Table 6-5 Average Percentage Change in Life-Cycle Costs, 10-Year, Alaska 

Building Standard Edition 

Type 2001 2004 2007 LEC 

APART04 0.1 -1.8 -2.3 -1.7 

APART06 0.0 -1.8 -2.2 -1.5 

DORMI04 2.2 -1.1 -1.8 -2.4 

DORMI06 0.0 -2.2 -2.6 -2.2 

HOTEL15 0.0 -2.5 -2.1 -1.8 

HIGHS02 0.4 -0.4 -0.7 -1.6 

OFFIC03 3.6 1.6 0.9 -0.5 

OFFIC08 3.7 1.5 1.1 -0.0 

OFFIC16 0.0 -0.9 -0.4 -0.2 

RETAIL1 1.7 0.0 -0.7 -0.2 

RSTRNT1 4.5 2.7 2.4 1.0 

Average 1.5 -0.5 -0.8 -1.0 

6.1.5 City Comparisons 

Simulations are run for 6 cities located in Alaska: Anchorage, Juneau, and Kodiak in 

Climate Zone 7 and Barrow, Fairbanks, and Nome in Climate Zone 8. The results vary 

across cities within Alaska for several reasons. First, the state is covered by two climate 

zones. The ASHRAE 90.1 building design requirements vary across climate zones and 

will impact the relative energy efficiency of the building. Second, cities within the same 

climate zone still have some variation in the local climate, which can lead to variation in 

energy consumption. Third, construction material and labor costs vary by locality. 

As can be seen in Table 6-6, average reduction in energy use for all building types from 

adopting newer energy standard editions is greater for the cities located in Zone 7. For the 

LEC design, Zone 7 realizes a change in average energy use of -23.1 % compared 

to -10.2 % for Zone 8. The extreme case is Barrow, which realizes an energy use increase 

of over 10 % for both ASHRAE 90.1-2004 and ASHRAE 90.1-2007 relative to ASHRAE 

90.1-1999 because of its very cold climate. 

25
 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Alaska 

Table 6-6 Average Percentage Change in Energy Use from Adoption of Newer 

Standard Editions by City, Alaska 

Cities Zone Standard Edition 

2001 2004 2007 LEC 

Anchorage 7 -0.3 -3.0 -10.5 -22.0 

Juneau 7 -0.2 -3.6 -11.7 -23.1 

Kodiak 7 -0.3 -4.4 -12.0 -24.2 

Barrow 8 -0.1 10.8 10.6 -1.6 

Fairbanks 8 -0.3 -2.5 -3.1 -14.6 

Nome 8 -0.2 -2.1 -2.4 -14.4 

Average -0.2 -0.8 -4.8 -16.7 

The variations in energy costs across cities are a result of two factors, the reductions in 

energy use and the fuel source of the reduction. Table 6-7 shows that the average 

reduction in energy costs for all building types is lower for cities in Zone 8 relative to 

cities in Zone 7. For the LEC design, Zone 7 realizes an average change in energy costs 

of -31.9 % compared to -23.4 % for Zone 8. 

The percentage change in energy costs is greater than the percentage change in energy 

use because the percentage reduction in electricity consumption is greater than the 

reduction in natural gas consumption. In some cases, electricity consumption is decreased 

while natural gas consumption is increased. Nowhere is this more apparent than in 

Barrow, Alaska. Even though Barrow has an increase in total energy use of 11 %, it 

realizes a decrease in energy costs of over 4 % for both ASHRAE 90.1-2004 and ASHRAE 

90.1-2007 relative to ASHRAE 90.1-1999. The lower cost of natural gas use relative to 

electricity use is significant enough to overwhelm the increase in total energy use. 

Table 6-7 Average Percentage Change in Energy Costs by City, 10-Year, Alaska 

Cities Zone Standard Edition 

2001 2004 2007 LEC 

Anchorage 7 -0.5 -15.0 -17.9 -31.4 

Juneau 7 -0.4 -15.4 -18.4 -31.6 

Kodiak 7 -0.4 -16.3 -18.7 -32.8 

Barrow 8 -0.1 -4.4 -4.8 -17.6 

Fairbanks 8 -0.6 -12.2 -12.8 -26.0 

Nome 8 -0.3 -12.6 -12.9 -26.4 

Average -0.4 -12.7 -14.3 -27.6 

Table 6-8 reports changes in energy-related carbon emissions by city for Alaska. For 5 of 

the 6 cities, the more stringent standard editions result in greater reductions in carbon 

26
 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Alaska 

emissions. As with energy use, the cities in Zone 7 realize a greater average change in 

emissions than the cities in Zone 8, -29.0 % versus -18.5 % for the LEC design, on 

average. For both Zone 7 and Zone 8, adopting ASHRAE 90.1-2004 and ASHRAE 

90.1-2007 would decrease energy-related carbon emissions overall. Barrow realizes an 

increase in average carbon emissions for ASHRAE 90.1-2004 and ASHRAE 90.1-2007, 

which is driven by the increase in energy use. 

Table 6-8 Average Percentage Change in Carbon Emissions by City, 10-Year, 

Alaska 

Cities Zone Standard Edition 

2001 2004 2007 LEC 

Anchorage 7 -0.4 -10.9 -15.2 -28.2 

Juneau 7 -0.3 -11.4 -16.0 -28.8 

Kodiak 7 -0.4 -12.4 -16.4 -30.0 

Barrow 8 -0.1 1.2 0.8 -11.7 

Fairbanks 8 -0.4 -8.5 -9.2 -21.8 

Nome 8 -0.3 -8.7 -9.1 -22.1 

Average -0.3 -8.9 -11.1 -23.8 

The data reported in Table 6-9 show that, over a 10-year period, average life-cycle costs 

increase for all cities for the ASHRAE 90.1-2001 design compared to ASHRAE 

90.1-1999. The ASHRAE 90.1-2007 and LEC designs result in the lowest average 

life-cycle costs of all building design alternatives for one city and 4 cities, respectively. 

For the ASHRAE 90.1-2001, -2004, -2007 and LEC designs, the cities located in Zone 7 

realize smaller increases and/or greater decreases in their average percentage changes in 

life-cycle costs than cities in Zone 8. The adoption of any of the newer standard editions 

increases life-cycle costs for the city of Barrow. 

Table 6-9 Average Percentage Change in Life-Cycle Costs by City, 10-Year, Alaska 

Cities Zone Standard Edition 

2001 2004 2007 LEC 

Anchorage 7 1.5 -0.8 -1.3 -1.5 

Juneau 7 1.5 -0.8 -1.4 -1.4 

Kodiak 7 1.4 -0.9 -1.1 -1.3 

Barrow 8 1.4 0.4 0.3 0.0 

Fairbanks 8 1.5 -0.2 -0.4 -1.0 

Nome 8 1.4 -0.5 -0.5 -0.9 

Average 1.5 -0.5 -0.8 -1.0 

27
 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Alaska 

6.2 Total Savings 

How much can Alaska save, in terms of energy use, energy costs, and carbon emissions, 

from adopting a more stringent state energy code for commercial buildings? What are the 

life-cycle costs associated with the new energy code adoption? To answer these 

questions, it is necessary to estimate savings per unit of floor area for each building type 

in the state. 

6.2.1 Energy Use 

Table 6-10 reports the average per unit change in annual energy use by building type and 

building design in the state.16 The reduction per m2 (ft2

) is multiplied by the estimated m2 

(ft2) of new construction of each building type, and Table 6-11 reports the estimated 

average annual floor area of new construction and the total annual change in energy use 

for each building type. The weightings within a category (e.g., small, medium, and large 

office buildings) are based on the national average percentage of new building 

construction for the category that is represented by each subcategory.17 

Table 6-10 Average Per Unit Change in Annual Energy Use, Alaska 

Building Standard Edition 

Type 2001 

kWh/m2 kBtu/ft2 

2004 

kWh/m2 kBtu/ft2 

2007 

kWh/m2 kBtu/ft2 

LEC 

kWh/m2 kBtu/ft2 

APART04 

APART06 

-0.1 -0.0 

-0.2 -0.0 

-1.4 -0.5 

-1.6 -0.5 

-12.6 -4.0 

-12.0 -3.8 

-31.7 -10.0 

-29.6 -9.4 

DORMI04 

DORMI06 

-0.4 -0.1 

-0.2 -0.1 

3.4 1.1 

1.7 0.5 

-10.6 -3.4 

-10.9 -3.5 

-36.5 -11.6 

-27.7 -8.8 

HOTEL15 -0.5 -0.2 -0.2 -0.1 12.1 3.8 -13.0 -4.1 

HIGHS02 -0.1 -0.0 0.7 0.2 -10.0 -3.2 -40.2 -12.7 

OFFIC03 

OFFIC08 

OFFIC16 

-0.6 -0.2 

-1.0 -0.3 

-0.7 -0.2 

1.3 0.4 

-3.0 -1.0 

0.4 0.1 

-6.8 -2.1 

-6.1 -1.9 

13.1 4.2 

-31.8 -10.1 

-27.5 -8.7 

-13.9 -4.4 

RETAIL1 -0.2 -0.1 2.0 0.6 -12.5 -4.0 -52.7 -16.7 

RSTRNT1 -0.9 -0.3 5.0 1.6 -28.4 -9.0 -88.2 -28.0 

The total annual reduction in energy use ranges widely across building designs, but the 

ASHRAE 90.1-2001, ASHRAE 90.1-2007, and LEC designs all decrease overall energy 

use across the state. Adopting ASHRAE 90.1-2001 results in an annual decrease of 

65.0 MWh (221.9 MBtu) while adopting ASHRAE 90.1-2007 saves 793.1 MWh 

(2.7 GBtu) annually. The adoption of the LEC design as the state’s energy code would 

save energy for all building types and 5.6 GWh (19.3 GBtu) of total energy use annually 

16 A simple average for a state is used because no data for a weighted average is available regarding the
 

amount of new construction on a city-by-city basis.
 

17 State-level subcategory data are not available.
 

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Alaska 

for one year’s worth of new construction for these building types. The adoption of the 

ASHRAE 90.1-2004 design increases total annual energy use by 106.8 MWh (365 MBtu) 

even though the overall average percentage change in energy use is negative for this 

building design. This emphasizes the importance of estimating aggregate impacts instead 

of relying solely on simple average percentage changes. 

Table 6-11 Statewide Change in Annual Energy Use for One Year of Construction, 

Alaska 

Building 

Type 

Subcat. 

Weight. m 2 

(1000s) 

ft2 

(1000s) 

Standard Edition 

2001 

MWh MBtu 

2004 

MWh MBtu 

2007 

MWh MBtu 

LEC 

MWh MBtu 

APART04 

APART06 

44.9 % 

55.1 % 

1.7 

2.0 

18 

22 

-0 -1 

-0 -1 

-2 -8 

-3 -11 

-21 -72 

-25 -84 

-53 -182 

-61 -208 

HOTEL15 100.0 % 25.2 271 -13 -43 -5 -16 304 1038 -328 -1120 

HIGHS02 100.0 % 46.2 497 -6 -20 59 203 -312 -1065 -1467 -5010 

OFFIC03 

OFFIC08 

OFFIC16 

37.4 % 

40.4 % 

22.2 % 

16.9 

18.2 

10.0 

182 

196 

108 

-11 -36 

-18 -62 

-7 -24 

12 42 

-55 -187 

4 15 

-168 -575 

-111 -379 

131 448 

-678 -2315 

-501 -1712 

-139 -476 

RETAIL1 100.0 % 41.6 448 -8 -27 83 285 -519 -1771 -2194 -7491 

RSTRNT1 100.0 % 2.5 27 -2 -8 13 44 -72 -247 -225 -767 

Total 164.3 1769 -65 -222 107 365 -793 -2708 -5646 -19 279 

Note: Dormitories are excluded because no such floor area category is reported in the construction data. 

Assuming that the buildings considered in this study, which represent 56.8 % of all new 

commercial floor space in the state, are generally representative of the entire new 

commercial building stock in the state, the results can be extrapolated to estimate the total 

statewide savings from LEC adoption in new commercial buildings to be 9.9 GWh 

(33.9 GBtu) per year. These savings imply 99.4 GWh (339 GBtu) in energy savings over 

the 10-year study period. In comparison, ASHRAE 90.1-2007 would save 1.4 GWh 

(4.8 GBtu) annually or 14.0 GWh (47.7 GBtu) over the 10-year study period. 

The relative reduction in energy use across the 9 building types with reported floor area 

data varies by building design. The greatest reductions for ASHRAE 90.1-2004 are found 

in mid-sized office buildings while for the ASHRAE 90.1-2007 and LEC designs, the 

greatest reductions are realized by retail stores and high schools. ASHRAE 90.1-2004 and 

ASHRAE 90.1-2007 result in an increase in energy use for five and two building types, 

respectively. The ASHRAE 90.1-2004 design increases total energy use for the low-rise 

and high-rise office buildings, high schools, retail stores, and restaurants relative to 

ASHRAE 90.1-1999 because of the changes in building envelope requirements for cities 

in Zone 8 as a result of the condensing of climate zones. Interestingly, four of these 

building types realized small average percentage decreases in energy use (see Table 6-2), 

which emphasizes the importance of estimating the total energy use impacts. For the 

ASHRAE 90.1-2007 design, the two high-rise buildings with 100 % window glazing 

realize increases in statewide energy use because of the relaxation of window U-factors 

29
 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Alaska 

and stricter window SHGC requirements for cities in Zone 8. The adoption of ASHRAE 

90.1-2007 leads to an increase in natural gas consumption that overwhelms any reduction 

in electricity consumption. 

The statewide change in energy use varies across building types within a building design. 

Building types that represent a greater amount of new floor area realize the largest 

changes in aggregate energy use. The building types that have the greatest percentage 

reduction in energy use are not always the same buildings that lead to the greatest total 

reductions for the state. For example, the building types that lead to the greatest estimated 

reductions in energy use for the LEC design -- retail stores and high schools -- rank 2nd 

and 10th in percentage reduction, respectively, among the 11 building types, as reported 

in Table 6-2. 

6.2.2 Energy Costs 

Table 6-12 reports the average per unit change in energy costs by building type and 

building design. Energy costs are calculated using the annual energy use, state average 

energy cost rates, and regional energy price escalation rates as defined in Section 3.2. 

Table 6-12 Average Per Unit Change in Energy Costs, 10-Year, Alaska 

Building Standard Edition 

Type 2001 

$/m2 $/ft2 

2004 

$/m2 $/ft2 

2007 

$/m2 $/ft2 

LEC 

$/m2 $/ft2 

APART04 

APART06 

-$0.16 

-$0.18 

-$0.01 

-$0.02 

-$23.51 

-$23.74 

-$2.18 

-$2.21 

-$26.75 

-$26.81 

-$2.48 

-$2.49 

-$41.65 

-$41.31 

-$3.87 

-$3.84 

DORMI04 

DORMI06 

-$0.46 

-$0.23 

-$0.04 

-$0.02 

-$21.19 

-$24.34 

-$1.97 

-$2.26 

-$25.09 

-$28.29 

-$2.33 

-$2.63 

-$41.88 

-$43.04 

-$3.89 

-$4.00 

HOTEL15 -$0.57 -$0.05 -$22.32 -$2.07 -$17.41 -$1.62 -$32.41 -$3.01 

HIGHS02 -$0.14 -$0.01 -$10.57 -$0.98 -$13.23 -$1.23 -$34.63 -$3.22 

OFFIC03 

OFFIC08 

OFFIC16 

-$0.72 

-$1.15 

-$0.80 

-$0.07 

-$0.11 

-$0.07 

-$9.31 

-$11.08 

-$9.78 

-$0.87 

-$1.03 

-$0.91 

-$12.26 

-$12.07 

-$4.16 

-$1.14 

-$1.12 

-$0.39 

-$32.47 

-$29.13 

-$21.37 

-$3.02 

-$2.71 

-$1.99 

RETAIL1 -$0.22 -$0.02 -$14.11 -$1.31 -$17.99 -$1.67 -$36.17 -$3.36 

RSTRNT1 -$1.03 -$0.10 -$18.87 -$1.75 -$28.78 -$2.67 -$68.99 -$6.41 

Table 6-13 reports the statewide changes in total energy costs by building type and 

building design, which account for one year’s worth of new construction evaluated over 

10 years of building operation. The ASHRAE 90.1-2001 design realizes small reductions 

in energy costs ($74 323). ASHRAE 90.1-2004, ASHRAE 90.1-2007, and the LEC design 

realize decreases in energy costs of $2.2 million, $2.4 million, and $5.5 million 

respectively. All the building types that realize an increase in total energy use from the 

adoption of the ASHRAE 90.1-2004 or ASHRAE 90.1-2007 designs realize a decrease in 

30
 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Alaska 

total energy costs because the increase in natural gas costs is less than the decrease in 

electricity costs. 

Assuming that the buildings considered in this study, which represent 56.8 % of all new 

commercial floor space in the state, are generally representative of the entire new 

commercial building stock in the state, the results for ASHRAE 90.1-2001, ASHRAE 

90.1-2004, ASHRAE 90.1-2007, and the LEC design can be extrapolated to estimate 

statewide reductions in energy costs of $130 850, $3.9 million, $4.3 million, and 

$9.8 million over the 10-year study period, respectively. 

Table 6-13 Statewide Change in Energy Costs for One Year of Construction, 

10-Year, Alaska 

Building Subcategory m 2 ft2 Standard Edition 

Type Weighting (1000s) (1000s) 2001 2004 2007 LEC 

APART04 44.9 % 1.7 18 -$265 -$39 458 -$44 896 -$69 920 

APART06 55.1 % 2.0 22 -$365 -$48 803 -$55 121 -$84 935 

HOTEL15 100 % 25.2 271 -$14 307 -$562 750 -$438 938 -$817 228 

HIGHS02 100 % 46.2 497 -$6672 -$488 114 -$611 097 -$1 599 031 

OFFIC03 37.4 % 16.9 182 -$12 104 -$157 269 -$207 099 -$548 262 

OFFIC08 40.4 % 18.2 196 -$20 863 -$201 693 -$219 820 -$530 469 

OFFIC16 22.2 % 10.0 108 -$8054 -$97 980 -$41 692 -$214 100 

RETAIL1 100 % 41.6 448 -$9068 -$587 353 -$748 800 -$1 505 613 

RSTRNT1 100 % 2.5 27 -$2624 -$48 044 -$73 271 -$175 609 

Total 164.3 1769 -$74 323 -$2 231 464 -$2 440 734 -$5 545 167 

Note: Dormitories are excluded because no such floor area category is reported in the construction data. 

6.2.3 Energy-related Carbon Emissions 

Table 6-14 reports the average reduction in energy-related carbon emissions over 10 

years, per m 

2 (ft2

), by building type and building design. The carbon emissions estimation 

approach is defined in Section 5.3. 

31
 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Alaska 

Table 6-14 Average Per Unit Change in Carbon Emissions, 10-Year, Alaska
 

Building Standard Edition 

Type 2001 

kg/m2 lb/ft2 

2004 

kg/m2 lb/ft2 

2007 

kg/m2 lb/ft2 

LEC 

kg/m2 lb/ft2 

APART04 

APART06 

-0.9 -0.2 

-1.0 -0.2 

-112.5 -23.0 

-113.8 -23.3 

-141.7 -29.0 

-141.3 -28.9 

-235.8 -48.3 

-231.5 -47.4 

DORMI04 

DORMI06 

-2.6 -0.5 

-1.3 -0.3 

-95.6 -19.6 

-112.6 -23.1 

-131.4 -26.9 

-146.8 -30.1 

-242.9 -49.7 

-237.3 -48.6 

HOTEL15 -3.3 -0.7 -105.3 -21.6 -66.9 -13.7 -168.9 -34.6 

HIGHS02 -0.8 -0.2 -48.2 -9.9 -70.8 -14.5 -202.9 -41.5 

OFFIC03 

OFFIC08 

OFFIC16 

-4.2 -0.9 

-6.6 -1.4 

-4.7 -1.0 

-43.0 -8.8 

-55.9 -11.5 

-45.5 -9.3 

-70.2 -14.4 

-64.5 -13.2 

-3.2 -0.7 

-203.1 -41.6 

-171.6 -35.2 

-118.0 -24.2 

RETAIL1 -1.3 -0.3 -64.0 -13.1 -100.3 -20.5 -236.3 -48.4 

RSTRNT1 -6.0 -1.2 -82.6 -16.9 -171.1 -35.0 -435.3 -89.1 

Table 6-15 applies the Table 6-14 results to one year’s worth of new building 

construction in the state to estimate statewide reduction in carbon emissions from 

adoption of more energy efficient codes. The total reduction in carbon emissions ranges 

widely across building designs, but the ASHRAE 90.1-2001, ASHRAE 90.1-2004, 

ASHRAE 90.1-2007, and LEC designs decrease carbon emissions overall. The adoption 

of ASHRAE 90.1-2004 and ASHRAE 90.1-2007 result in savings of 10 375 metric tons 

and 12 486 metric tons over a 10-year study period, respectively. All building types that 

realized an increase in total energy use from adopting ASHRAE 90.1-2004 or ASHRAE 

90.1-2007 realize a decrease in carbon emissions because the emissions resulting from 

the increase in natural gas consumption are less than the decrease in emissions from the 

reduction in electricity consumption. The adoption of LEC as the state’s energy code 

decreases carbon emissions by 33 177 metric tons over the 10-year study period for one 

year’s worth of new commercial construction for these building types. 

Assuming that the buildings considered in this study are generally representative of the 

entire new commercial building stock in the state, the results for ASHRAE 90.1-2004, 

ASHRAE 90.1-2007, and LEC can be extrapolated to estimate statewide reductions in 

carbon emissions of 18 265 metric tons, 21 983 metric tons, and 58 411 metric tons over 

the 10-year study period, respectively. 

32
 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Alaska 

Table 6-15 Statewide Change in Total Carbon Emissions for One Year of 

Construction, 10-Year, Alaska – Metric Tons 

Building Subcategory m 2 ft2 Standard Edition 

Type Weighting (1000s) (1000s) 2001 2004 2007 LEC 

APART04 44.9 % 1.7 18 -2 -189 -238 -396 

APART06 55.1 % 2.0 22 -2 -234 -291 -476 

HOTEL15 100.0 % 25.2 271 -83 -2656 -1687 -4259 

HIGHS02 100.0 % 46.2 497 -39 -2224 -3268 -9366 

OFFIC03 37.4 % 16.9 182 -70 -725 -1186 -3430 

OFFIC08 40.4 % 18.2 196 -121 -1018 -1174 -3125 

OFFIC16 22.2 % 10.0 108 -47 -456 -32 -1183 

RETAIL1 100.0 % 41.6 448 -53 -2662 -4175 -9835 

RSTRNT1 100.0 % 2.5 27 -15 -210 -436 -1108 

Total 164.3 1769 -431 -10 375 -12 486 -33 177 

Note: Dormitories are excluded because no such floor area category is reported in the 

construction data. 

6.2.4 Life-Cycle Costs 

Table 6-16 reports the average change in life-cycle cost over 10 years, per m2 (ft2

), by 

building type and building design. As discussed in Section 5.2, life-cycle costs include 

construction costs, maintenance, repair, and replacement costs, energy costs, and residual 

values. 

Table 6-16 Average Per Unit Change in Life-Cycle Costs, 10-Year, Alaska 

Building Standard Edition 

Type 2001 

$/m2 $/ft2 

2004 

$/m2 $/ft2 

2007 

$/m2 $/ft2 

LEC 

$/m2 $/ft2 

APART04 $1.00 $0.09 -$22.37 -$2.08 -$28.29 -$2.63 -$21.31 -$1.98 

APART06 $0.50 $0.05 -$22.72 -$2.11 -$27.73 -$2.58 -$18.79 -$1.75 

DORMI04 $25.64 $2.38 -$12.22 -$1.14 -$20.47 -$1.90 -$27.80 -$2.58 

DORMI06 $0.23 $0.02 -$29.21 -$2.71 -$34.13 -$3.17 -$28.95 -$2.69 

HOTEL15 -$0.24 -$0.02 -$31.41 -$2.92 -$26.03 -$2.42 -$22.59 -$2.10 

HIGHS02 $4.92 $0.46 -$4.31 -$0.40 -$7.27 -$0.68 -$18.12 -$1.68 

OFFIC03 $35.01 $3.25 $15.85 $1.47 $8.74 $0.81 -$4.79 -$0.44 

OFFIC08 $37.12 $3.45 $15.27 $1.42 $10.66 $0.99 -$0.44 -$0.04 

OFFIC16 -$0.13 -$0.01 -$9.25 -$0.86 -$4.13 -$0.38 -$1.42 -$0.13 

RETAIL1 $13.89 $1.29 -$0.24 -$0.02 -$5.29 -$0.49 -$1.58 -$0.15 

RSTRNT1 $68.46 $6.36 $40.66 $3.78 $35.97 $3.34 $15.27 $1.42 

Table 6-17 applies the Table 6-16 results to one year’s worth of new building 

construction in the state to estimate statewide changes in life-cycle costs from adoption of 

more energy-efficient state energy codes for commercial buildings. Total reductions in 

life-cycle costs over the 10-year study period vary across building designs. Adoption of 

33
 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Alaska 

the ASHRAE 90.1-2001 design results in an increase in life-cycle costs for seven of nine 

building types. The ASHRAE 90.1-2004 and -2007 designs result in a decrease in lifecycle costs for six of nine building types, with total life-cycle costs decreasing by 

$463 949 and $815 858, respectively. The LEC design decreases life-cycle costs for eight 

of nine building types, and decreases total life-cycle costs by $1.3 million. The building 

types that realize a decrease in life-cycle costs far outweigh in terms of construction 

volume the building type that realizes an increase in life-cycle costs for the LEC design. 

For a 10-year study period, it is cost-effective to adopt newer editions of ASHRAE 

90.1-2004, ASHRAE 90.1-2007, or the LEC design. 

Assuming that the buildings considered in this study are generally representative of the 

entire new commercial building stock in the state, the results for ASHRAE 90.1-2001, 

ASHRAE 90.1-2004, ASHRAE 90.1-2007, and LEC can be extrapolated to estimate 

statewide changes in life-cycle costs of $3.8 million, -$816 812, -$1.4 million, 

and -$2.4 million over the 10-year study period, respectively. 

Table 6-17 Statewide Change in Life-Cycle Costs for One Year of Construction, 

10-Year, Alaska 

Building Subcategory m 2 ft2 Standard Edition 

Type Weighting (1000s) (1000s) 2001 2004 2007 LEC 

APART04 44.9 % 1.7 18 $1679 -$37 552 -$47 483 -$35 770 

APART06 55.1 % 2.0 22 $1030 -$46 717 -$57 020 -$38 625 

HOTEL15 100.0 % 25.2 271 -$5984 -$792 009 -$656 255 -$569 600 

HIGHS02 100.0 % 46.2 497 $153 108 -$134 211 -$226 537 -$564 232 

OFFIC03 37.4 % 16.9 182 $591 248 $267 717 $147 535 -$80 821 

OFFIC08 40.4 % 18.2 196 $675 971 $278 128 $194 045 -$8033 

OFFIC16 22.2 % 10.0 108 -$1324 -$92 661 -$41 419 -$14 218 

RETAIL1 100.0 % 41.6 448 $578 191 -$10 138 -$220 286 -$65 841 

RSTRNT1 100.0 % 2.5 27 $174 273 $103 494 $91 562 $38 862 

Total 164.3 1769 $2 168 193 -$463 949 -$815 858 -$1 338 279 

Note: Dormitories are excluded because no such floor area category is reported in the construction data. 

6.3 State Summary 

Alaska is one of the states that has no state energy code for commercial buildings, and is 

located in the coldest climates in the United States. On average, adopting ASHRAE 

90.1-2004 or ASHRAE 90.1-2007 leads to reductions in energy use, energy costs, and 

cradle-to-grave energy-related carbon emissions at negative life-cycle costs. Based on the 

average annual new construction in the state from 2003 to 2007 and a 10-year study 

period, adopting ASHRAE 90.1-2007 as the state’s energy code for commercial buildings 

would lead to energy savings of 14.0 GWh (47.7 GBtu), energy cost savings of 

$4.3 million, and 21 983 metric tons of carbon emissions reductions while saving 

$1.4 million in life-cycle costs for one year’s worth of commercial building construction. 

34
 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

Alaska 

However, adopting the ASHRAE 90.1-2004 or ASHRAE 90.1-2007 design increases 

energy use for some location-building type combinations in Alaska. ASHRAE 90.1-2004 

condenses the 26 climate zones defined in ASHRAE 90.1-1999/2001 into 8 climate zones. 

As a result, some of the building envelope requirements (window U-factors and 

insulation R-values) are slightly less stringent for cities in Zone 8. Additionally, ASHRAE 

90.1-2007 restricts the window SHGC below that required in ASHRAE 90.1-2004 for 

Alaska’s climate zones, leading to losses in beneficial heat gain through fenestration. 

The adoption of the LEC design leads to savings in total energy use and energy-related 

carbon emissions in a cost-effective manner. Based on the average annual new 

construction in the state from 2003 to 2007 and a 10-year study period, adopting the LEC 

design would be even more beneficial for the state than adopting ASHRAE 90.1-2007, 

with savings of 99.4 GWh (339.4 GBtu), $9.8 million of energy costs, 58 411 metric tons 

of carbon emissions, and $2.4 million of life-cycle costs for one year’s worth of 

commercial building construction. 

35
 
Alaska 

36 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

7 

Arizona 

Arizona 

Arizona is located in the Mountain Census Division and spans four climate zones 

(Zone 2B, Zone 3B, Zone 4B, and Zone 5B). The state does not have a commercial 

building energy code, and is assumed to build to the current minimum industry practices 

represented by ASHRAE 90.1-1999 requirements. However, it is common for cities in 

Arizona to adopt local energy codes for commercial buildings. Arizona is the only state 

in this study in which more than one city has adopted a local energy code that is two 

editions of ASHRAE 90.1 beyond its assumed baseline standard edition (ASHRAE 

90.1-1999). Table 7-1 provides an overview of Arizona’s simulated energy use keyed to 

building types and energy standard editions. Average energy use varies across building 

types and building designs. The 8-story office building uses the least amount of energy 

for the ASHRAE 90.1-1999 design at 122 kWh/m2 (39 kBtu/ft2

) annually. The 4-story 

dormitory uses the least amount of energy for the LEC design at 79 kWh/m2 (25 kBtu/ft2

) 

annually. The restaurant uses the greatest amount of energy for the ASHRAE 90.1-1999 

design at 195 kWh/m2 (62 kBtu/ft2) annually. The high school uses the greatest amount 

of energy for the LEC design at 137 kWh/m2 (43 kBtu/ft2

) annually. 

Table 7-1 Average Annual Energy Use by Building Type and Standard Edition, 

Arizona 

Building 

Type 

Standard Edition 

1999 

kWh/m2 kBtu/ft2 

2001 

kWh/m2 kBtu/ft2 

2004 

kWh/m2 kBtu/ft2 

2007 

kWh/m2 kBtu/ft2 

LEC 

kWh/m2 kBtu/ft2 

APART04 

APART06 

159 50 

158 50 

157 50 

156 50 

128 41 

127 40 

121 38 

121 39 

104 33 

102 32 

DORMI04 

DORMI06 

126 40 

175 56 

122 39 

171 54 

99 31 

140 44 

93 29 

132 42 

79 25 

111 35 

HOTEL15 145 46 143 45 120 38 119 38 101 32 

HIGHS02 178 56 175 56 166 53 154 49 137 43 

OFFIC03 

OFFIC08 

OFFIC16 

134 43 

122 39 

143 45 

130 41 

118 38 

141 45 

119 38 

106 34 

130 41 

106 34 

103 33 

133 42 

82 26 

82 26 

109 35 

RETAIL1 144 46 140 45 124 39 107 34 91 29 

RSTRNT1 195 62 188 60 167 53 151 48 105 33 

The detailed analysis for this state reports the changes in energy use, energy costs, 

energy-related carbon emissions, and life-cycle costs from adoption of increasingly 

stringent energy standard editions. The results are reported in terms of average 

percentage savings on a statewide and city-by-city basis and as total savings on a 

statewide basis. 

37
 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Arizona 

7.1 Percentage Savings 

Changes in percentage terms allow for direct comparisons across building types and 

locations within a state. This section discusses the average percentage changes from 

investing in more energy efficient designs for the state of Arizona. 

7.1.1 Energy Use 

Table 7-2 shows significant changes in energy use from adopting ASHRAE 90.1-2001 

relative to ASHRAE 90.1-1999 with all 11 building types realizing increases in energy use 

of 2.4 % to 11.1 %. Three cities in Arizona have already adopted ASHRAE 90.1-2004 as 

their local energy code. As a result, adopting ASHRAE 90.1-2001 increases energy use 

for each of these three cities. There is a decrease in energy use for all 11 building types 

for ASHRAE 90.1-2004, with the percentage change in energy use ranging from -3.5 % 

to -10.9 % with an average of -7.6 %. The average change in energy use from 

constructing buildings using ASHRAE 90.1-2007 requirements ranges from -1.9 % 

to -19.9 %, with an overall average of -12.9 %. The smallest reduction in energy use is 

realized by the 16-story office building while the greatest reduction is realized by the 

retail store. 

Table 7-2 Average Percentage Change in Energy Use from Adoption of Newer 

Standard Editions, Arizona 

Building Standard Edition
 

Type
 2001 2004 2007 LEC 

APART04 11.1 -9.4 -14.3 -26.6 

APART06 11.1 -9.5 -13.6 -27.1 

DORMI04 9.9 -10.9 -16.4 -29.1 

DORMI06 10.3 -9.8 -15.2 -28.3 

HOTEL15 9.3 -8.8 -9.2 -23.1 

HIGHS02 2.4 -3.5 -10.8 -21.5 

OFFIC03 2.8 -6.0 -15.8 -34.7 

OFFIC08 4.6 -6.7 -8.8 -28.1 

OFFIC16 3.7 -4.7 -1.9 -19.6 

RETAIL1 5.1 -7.1 -19.9 -31.6 

RSTRNT1 4.7 -7.3 -16.1 -41.4 

Average 6.8 -7.6 -12.9 -28.3 

For the 16-story office building, ASHRAE 90.1-2004 is actually more energy efficient 

than ASHRAE 90.1-2007 because the maximum window SHGC requirement in Zone 2 

through Zone 5 is increased from ASHRAE 90.1-2004 to ASHRAE 90.1-2007 for 

buildings with greater than 40 % window glazing, making the requirement less strict. 

Buildings in warmer climates benefit from decreasing solar heat gains. The 100 % 

glazing amplifies the heat gain from the higher SHGC, which increases electricity 

38
 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Arizona 

consumption enough to overwhelm the energy efficiency gains obtained from other 

measures that decrease energy consumption, such as increased roof insulation R-values. 

The LEC design realizes the greatest reductions in energy use, with the change in energy 

use relative to ASHRAE 90.1-1999 ranging from -19.6 % to -41.4 % with an average 

of -28.3 %.The lowest reduction in energy use for the LEC design occurs in the buildings 

with the greatest window-to-wall ratios. Additionally, the high school realizes smaller 

reductions in energy use because of its unique occupant activity, significant occupancy 

during the school year and minimal occupancy during the summer. 

7.1.2 Energy Costs 

Table 7-3 shows a significant percentage change in energy costs over 10 years from 

adopting ASHRAE 90.1-2001 (3.7 % to 15.6 %), which mirrors the energy use results 

described above. There is a significant variation in the percentage change in average 

energy costs for ASHRAE 90.1-2004, ranging from -4.9 % to -13.3 % depending on the 

building type with an average of -9.3 %. The average change in energy costs from 

constructing buildings using ASHRAE 90.1-2007 requirements ranges from -0.4 % 

to -18.6 %, with an overall average of -12.8 %. The LEC design realizes the greatest 

change in energy costs, with the average change by building type ranging from -20.5 % 

to -43.6 % with an average of -31.2 % overall. 

Table 7-3 Average Percentage Change in Energy Costs, 10-Year, Arizona 

Building Standard Edition 

Type 2001 2004 2007 LEC 

APART04 15.4 -12.0 -15.9 -31.1 

APART06 15.6 -12.1 -15.3 -32.5 

DORMI04 14.4 -13.3 -16.9 -32.1 

DORMI06 15.0 -12.4 -16.7 -33.6 

HOTEL15 14.6 -11.3 -8.9 -26.4 

HIGHS02 3.8 -4.9 -11.4 -27.4 

OFFIC03 3.7 -6.4 -14.1 -34.9 

OFFIC08 4.7 -6.9 -7.8 -28.0 

OFFIC16 5.1 -5.4 -0.4 -20.5 

RETAIL1 6.6 -8.3 -18.6 -32.4 

RSTRNT1 6.8 -8.7 -14.6 -43.6 

Average 9.6 -9.3 -12.8 -31.2 

For the ASHRAE 90.1-2001 and -2004 designs, the average percentage change in energy 

costs is greater than the change in energy use for all building types because the 

percentage change in electricity consumption is greater than the change in natural gas 

consumption. Electricity is more expensive than natural gas on a per unit of energy basis, 

which increases the percentage change in energy costs. For 6 of 11 building types, the 

average percentage reduction in energy costs is less than the reduction in energy use from 

39
 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Arizona 

adopting the ASHRAE 90.1-2007 design because the percentage reduction in electricity 

consumption is less than the reduction in natural gas consumption. For the LEC design, 

the average reductions in energy costs are greater than the reductions in energy use for 10 

of 11 building types because the percentage reduction in electricity consumption is 

greater than the reduction in natural gas consumption. For 7 of the 11 building types, 

adopting the LEC design increases natural gas consumption while decreasing electricity 

consumption. The buildings use electricity for all energy consumption except for the 

heating component of the HVAC system, which uses natural gas. The energy efficiency 

measures adopted lead to a decrease in energy use for both lighting and cooling the 

building, but an increase in heating loads. Since electricity is more expensive than natural 

gas on a per unit of energy basis, the shift in energy use from cooling to heating 

magnifies the decrease in energy costs for the building. 

7.1.3 Energy-related Carbon Emissions 

The significant increases in energy use lead to percentage increases (3.9 % to 16.9 %) in 

cradle-to-grave energy-related carbon emissions from adopting the ASHRAE 90.1-2001 

design across all building types. Table 7-4 shows a significant decrease in average 

energy-related carbon emissions for ASHRAE 90.1-2004 for all building types, with 

changes ranging from -5.3 % to -13.9 % with an average of -9.7 %. The ASHRAE 

90.1-2007 design leads to slightly greater reductions overall than ASHRAE 90.1-2004, 

with the average change in carbon emissions ranging from 0.0 % to -18.3 % with an 

overall average of -12.8 %. The LEC design leads to the greatest average changes in 

carbon emissions, ranging from -20.8 % to -44.2 % depending on the building type with 

an average of -31.9 % across all building types. 

Table 7-4 Average Percentage Change in Energy-related Carbon Emissions, 10­

Year, Arizona 

Building Standard Edition 

Type 2001 2004 2007 LEC 

APART04 16.8 -12.7 -16.3 -32.4 

APART06 16.9 -12.7 -15.7 -34.0 

DORMI04 15.6 -13.9 -17.0 -32.9 

DORMI06 16.4 -13.0 -17.1 -35.1 

HOTEL15 16.2 -12.0 -8.8 -27.3 

HIGHS02 4.2 -5.3 -11.6 -29.2 

OFFIC03 3.9 -6.5 -13.7 -35.0 

OFFIC08 4.8 -7.0 -7.6 -28.0 

OFFIC16 5.5 -5.5 0.0 -20.8 

RETAIL1 7.0 -8.5 -18.3 -32.6 

RSTRNT1 7.3 -9.1 -14.2 -44.2 

Average 10.4 -9.7 -12.8 -31.9 

40
 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Arizona 

As would be expected, a more energy efficient building design results in greater 

reductions in carbon emissions. Similar to energy costs, the percentage changes in carbon 

emissions are greater than the percentage changes in energy use for all building types 

from adopting ASHRAE 90.1-2001 and -2004 and 10 of 11 building types for the LEC 

design because the energy efficiency measures decrease electricity consumption by a 

greater percentage than natural gas consumption. Meanwhile, 6 of 11 building types 

realize smaller reductions in carbon emissions than reductions in energy use from 

adopting ASHRAE 90.1-2007. The reduction in electricity relative to natural gas 

consumption drives these results because electricity has a higher carbon emissions rate 

per unit of energy than natural gas in Arizona. 

7.1.4 Life-Cycle Costs 

The most cost-effective building design for each building type is bolded in Table 7-5. 

Life-cycle costs increase for the ASHRAE 90.1-2001 design compared to ASHRAE 

90.1-1999 for all 11 building types over a 10-year study period. The current state energy 

code is never the lowest cost option. ASHRAE 90.1-2004 and ASHRAE 90.1-2007 are the 

lowest cost building designs for two building types each. The change in life-cycle costs 

for ASHRAE 90.1-2004 and -2007 ranges from -2.2 % to 3.0 % depending on the building 

type. The LEC design is the lowest cost building design for seven building types, with the 

percentage change in life-cycle costs ranging from -5.2 % to -0.0 %. Given that all 

building types realize a reduction in life-cycle costs, the LEC design is cost-effective for 

the state to adopt as its state energy code for commercial buildings. 

Table 7-5 Average Percentage Change in Life-Cycle Costs, 10-Year, Arizona 

Building Standard Edition 

Type 2001 2004 2007 LEC 

APART04 1.4 -1.3 -1.8 -1.6 

APART06 1.4 -1.3 -1.7 -1.7 

DORMI04 5.1 0.8 -0.1 -1.6 

DORMI06 1.5 -1.6 -2.2 -2.4 

HOTEL15 1.6 -1.5 -1.3 -1.0 

HIGHS02 0.8 -0.3 -1.5 -2.8 

OFFIC03 4.7 2.4 0.6 -3.1 

OFFIC08 5.2 2.3 1.4 -2.3 

OFFIC16 0.7 -0.6 -0.0 -0.0 

RETAIL1 3.5 0.4 -1.7 -1.8 

RSTRNT1 6.2 3.0 0.8 -5.2 

Average 2.9 0.2 -0.7 -2.1 

7.1.5 City Comparisons 

Simulations are run for six cities located in Arizona: Phoenix, Tucson, and Yuma in 

Climate Zone 2B, Prescott in Zone 4B, and Flagstaff and Winslow in Climate Zone 5B. 

41
 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Arizona 

There are no significant population centers in the counties of Arizona located in Zone 3B. 

The results may vary across cities within Arizona for four reasons. First, the cities in the 

state selected for this study cover three climate zones. The ASHRAE 90.1 building design 

requirements vary across climate zones and will impact the relative energy efficiency of 

the building. Second, cities within the same climate zone still have some variation in the 

local climate, which can lead to variation in energy consumption. Third, construction 

material and labor costs vary by locality. Finally, three cities have adopted a stricter 

building energy code than the state (Flagstaff, Phoenix, and Tucson). 

As can be seen in Table 7-6, average reductions in energy use for all building types from 

adopting newer energy standard editions vary across and within climate zones. The 

variation within climate zones is a result of variation in local energy codes. The cities 

with no local energy code realize greater percentage reductions in energy use. Consider 

the adoption of ASHRAE 90.1-2007 for the three cities in Zone 2B. The two cities that 

have adopted ASHRAE 90.1-2004 as their local energy code realize an average reduction 

of 8.7 % while the city that has no local energy code realizes a reduction of 24.2 %. After 

controlling for local energy codes, cities in warmer climate zones realize greater 

percentage reductions in energy use. 

Table 7-6 Average Percentage Change in Energy Use from Adoption of Newer 

Standard Editions by City, Arizona 

Cities Zone Standard Edition 

2001 2004 2007 LEC 

Phoenix 2B 17.3 0.0 -8.6 -26.5
 

Tucson 2B 19.9 0.0 -8.7 -26.3
 

Yuma 2B -3.3 -17.9 -24.2 -39.2 

Prescott 4B -1.6 -13.8 -16.1 -31.0 

Flagstaff 5B 10.4 0.0 -3.7 -16.2 

Winslow 5B -1.7 -14.1 -16.2 -30.4 

Average 6.8 -7.6 -12.9 -28.3 

The variation in energy costs across cities is a result of three factors, the reduction in 

energy use, the fuel source of the reduction, and the local energy code. Table 7-7 shows 

that the cities that have adopted ASHRAE 90.1-2004 as their local energy code realize the 

smallest reductions in energy costs. The climate zone with the greatest reduction in 

energy use realizes the greatest reduction in energy costs for each of the building designs. 

Two of the six cities (Prescott and Winslow) realize larger percentage reductions in 

energy costs than percentage reductions in energy use for all building designs because the 

percentage reduction in electricity consumption is greater than the reduction in natural 

gas consumption. Since electricity is more expensive than natural gas on a per unit basis, 

greater relative reduction in electricity leads to additional reductions in energy costs. The 

42
 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Arizona 

other four cities realize lower reductions in energy costs than reductions in energy use for 

the ASHRAE 90.1-2007 design because the percentage reduction in electricity 

consumption is less than the reduction in natural gas consumption. 

Table 7-7 Average Percentage Change in Energy Costs by City, 10-Year, Arizona 

Cities Zone Standard Edition 

2001 2004 2007 LEC 

Phoenix 2B 19.8 0.0 -6.7 -26.5
 

Tucson 2B 24.2 0.0 -5.9 -26.3
 

Yuma 2B -3.4 -18.9 -24.1 -39.9 

Prescott 4B -1.8 -18.4 -19.2 -37.2 

Flagstaff 5B 20.7 0.0 -1.8 -20.6 

Winslow 5B -1.9 -18.2 -19.1 -36.4 

Average 9.6 -9.3 -12.8 -31.2 

Table 7-8 reports changes in energy-related carbon emissions by city for Arizona. For all 

cities, the more stringent standard editions result in greater reductions in carbon 

emissions. Prescott and Winslow realize greater reductions in carbon emissions than 

reductions in energy use for all building designs. Meanwhile, the other four cities realize 

smaller reductions in carbon emissions than energy use for the ASHRAE 90.1-2007 and 

LEC designs. 

Table 7-8 Average Percentage Change in Carbon Emissions by City, 10-Year, 

Arizona 

Cities Zone Standard Edition 

2001 2004 2007 LEC 

Phoenix 2B 19.5 0.0 -7.1 -27.5
 

Tucson 2B 24.0 0.0 -6.0 -27.2
 

Yuma 2B -3.1 -18.2 -24.1 -40.3 

Prescott 4B -1.6 -18.7 -19.6 -38.7 

Flagstaff 5B 22.9 0.0 -1.6 -22.5 

Winslow 5B -1.7 -18.5 -19.5 -37.9 

Average 10.0 -9.2 -13.0 -32.3 

The data reported in Table 7-9 show that, over a 10-year period, average life-cycle costs 

increase for all cities for the ASHRAE 90.1-2001 design compared to the local energy 

code. For the three cities with no local energy code, adopting the ASHRAE 90.1-2004 

design leads to a percentage increase in life-cycle costs. The additional energy efficiency 

measures increase construction costs and overwhelm lower future energy costs. Adoption 

of the ASHRAE 90.1-2007 design results in average reductions in life-cycle costs for four 

43
 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Arizona 

of the six cities. Adoption of the LEC design realizes the greatest average percentage 

reductions in life-cycle costs for all cities in all climate zones. For the LEC design, 

buildings in warmer climate zones realize greater percentage reductions in life-cycle 

costs. 

Table 7-9 Average Percentage Change in Life-Cycle Costs by City, 10-Year, 

Arizona 

Cities Zone Standard Edition 

2001 2004 2007 LEC 

Phoenix 2B 2.6 0.0 -1.5 -3.0 

Tucson 2B 2.8 0.0 -1.3 -2.5 

Yuma 2B 3.2 0.4 -1.1 -2.9 

Prescott 4B 3.1 0.4 0.1 -1.5 

Flagstaff 5B 2.7 0.0 -0.3 -1.3
 

Winslow 5B 3.1 0.4 0.0 -1.6
 

Average 2.9 0.2 -0.7 -2.1 

7.2 Total Savings 

How much can Arizona save, in terms of energy use, energy costs, and carbon emissions, 

from adopting a more stringent state energy code for commercial buildings? What are the 

life-cycle costs associated with the new energy code adoption? To answer these 

questions, it is necessary to estimate savings per unit of floor area for each building type 

in the state. 

7.2.1 Energy Use 

Table 7-10 reports the average per unit change in annual energy use by building type and 

building design in the state.18 The reduction per m2 (ft2

) is multiplied by the estimated m2 

(ft2) of new construction of each building type, and Table 7-11 reports the estimated 

average annual floor area of new construction and the total annual change in energy use 

for each building type. The weightings within a category (e.g., small, medium, and large 

office buildings) are based on the national average percentage of new building 

construction for the category that is represented by each subcategory.19 

18 A simple average for a state is used because no data for a weighted average is available regarding the
 

amount of new construction on a city-by-city basis.
 

19 State-level subcategory data are not available.
 

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Arizona 

Table 7-10 Average Per Unit Change in Annual Energy Use, Arizona
 

Building Standard Edition 

Type 2001 

kWh/m2 kBtu/ft2 

2004 

kWh/m2 kBtu/ft2 

2007 

kWh/m2 kBtu/ft2 

LEC 

kWh/m2 kBtu/ft2 

APART04 

APART06 

13.8 4.4 

13.8 4.4 

-15.1 -4.8 

-15.2 -4.8 

-22.0 -7.0 

-20.9 -6.6 

-39.4 -12.5 

-40.0 -12.7 

DORMI04 

DORMI06 

9.3 3.0 

13.8 4.4 

-13.8 -4.4 

-17.4 -5.5 

-19.8 -6.3 

-25.7 -8.2 

-34.0 -10.8 

-46.2 -14.7 

HOTEL15 11.0 3.5 -12.6 -4.0 -12.7 -4.0 -31.0 -9.8 

HIGHS02 3.4 1.1 -8.0 -2.5 -21.0 -6.7 -44.9 -14.2 

OFFIC03 

OFFIC08 

OFFIC16 

3.1 1.0 

4.4 1.4 

4.8 1.5 

-6.1 -1.9 

-8.3 -2.6 

-6.7 -2.1 

-17.9 -5.7 

-10.6 -3.4 

-2.8 -0.9 

-35.0 -11.1 

-32.5 -10.3 

-26.9 -8.5 

RETAIL1 6.2 2.0 -10.2 -3.2 -27.4 -8.7 -43.1 -13.7 

RSTRNT1 7.5 2.4 -14.3 -4.5 -30.0 -9.5 -75.5 -23.9 

The annual reduction in energy use, shown in Table 7-11, ranges widely across building 

designs, with ASHRAE 90.1-2001 increasing overall energy use and the other building 

designs decreasing energy use across the state relative to the current state and local codes. 

Adopting the ASHRAE 90.1-2001 design increases total annual energy use for the state 

because the increases in energy use for the cities that have already adopted ASHRAE 

90.1-2004 as their local energy code overwhelm the energy use reductions from the three 

cities with no local energy code. Adopting the ASHRAE 90.1-2004 and ASHRAE 

90.1-2007 designs result in annual decreases of 25.6 GWh (87.6 GBtu) and 54.0 GWh 

(184.5 GBtu), respectively. The adoption of the LEC design as the state’s energy code 

would save energy for all building types and 106.1 GWh (362.1 GBtu) of total energy use 

annually for one year’s worth of new construction for these building types. 

Table 7-11 Statewide Change in Annual Energy Use for One Year of Construction, 

Arizona 

Building 

Type 

Subcat. 

Weight. m 2 

(1000s) 

ft2 

(1000s) 

Standard Edition 

2001 

MWh MBtu 

2004 

MWh MBtu 

2007 

MWh MBtu 

LEC 

MWh MBtu 

APART04 

APART06 

44.9 % 

55.1 % 

94 

115 

1009 

1236 

1292 4410 

1588 5421 

-1413 

-1741 

-4825 

-5944 

-2063 -7043 

-2399 -8191 

-3696 

-4588 

-12 620 

-15 665 

HOTEL15 100.0 % 209 2254 2306 7873 -2632 -8987 -2660 -9083 -6488 -22 154 

HIGHS02 100.0 % 459 4938 1550 5292 -2807 -9585 -8196 -27 984 -16 060 -54 836 

OFFIC03 

OFFIC08 

OFFIC16 

37.4 % 

40.4 % 

22.2 % 

302 

325 

179 

3248 

3502 

1927 

923 3151 

1444 4931 

860 2935 

-2408 

-2693 

-1202 

-8221 

-9194 

-4105 

-6351 -21 684 

-3438 -11 738 

-493 -1685 

-13 540 

-10 571 

-4819 

-46 231 

-36 095 

-16 453 

RETAIL1 100.0 % 978 10 529 6026 20 575 -9978 -34 070 -26 805 -91 525 -42 206 -144 110 

RSTRNT1 100.0 % 54 584 407 1389 -774 -2644 -1627 -5554 -4093 -13 977 

Total 2715 29 227 16 394 55 978 -25 649 -87 575 -54 032 -184 487 -106 062 -362 141 

Note: Dormitories are excluded because no such floor area category is reported in the construction data. 

45
 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Arizona 

Assuming that the buildings considered in this study, which represent 57.1 % of all new 

commercial floor space in the state, are generally representative of the entire new 

commercial building stock in the state, the results can be extrapolated to estimate the total 

statewide savings from adopting the LEC design in new commercial buildings to be 

185.7 GWh (634.2 GBtu) per year. These savings imply 1.9 TWh (6.3 TBtu) in energy 

use savings over the 10-year study period. In comparison, ASHRAE 90.1-2007 would 

save 94.6 GWh (323.1 GBtu) annually or 946.3 GWh (3230.9 GBtu) over the 10-year 

study period. 

The relative statewide changes in energy use across the 9 building types with reported 

floor area data vary across and within the ASHRAE 90.1-2001, -2004, -2007, and LEC 

designs. For the ASHRAE 90.1-2007 and LEC designs, building types that represent the 

greatest amount of new floor area realize the largest changes in aggregate energy use, 

with retail stores and high schools realizing the greatest total reductions in energy use and 

accounting for 36.0 % and 16.9 %, respectively, of the combined new construction in the 

state for the building types in this study. All other building types represent 12.0 % or less 

of new construction. The amount of new construction overwhelms the relative percentage 

changes in energy use, with the retail store and high school ranked 3rd and 10th in 

percentage reduction, respectively, among the 11 building types for the LEC design as 

reported in Table 7-2. 

7.2.2 Energy Costs 

Table 7-12 reports the average per unit change in energy costs by building type and 

building design. Energy costs are calculated using the annual energy use, state average 

energy cost rates, and regional energy price escalation rates as defined in Section 3.2. 

Table 7-12 Average Per Unit Change in Energy Costs, 10-Year, Arizona 

Building Standard Edition 

Type 2001 

$/m2 $/ft2 

2004 

$/m2 $/ft2 

2007 

$/m2 $/ft2 

LEC 

$/m2 $/ft2 

APART04 

APART06 

$12.23 

$12.31 

$1.14 

$1.14 

-$12.83 

-$12.87 

-$1.19 

-$1.20 

-$16.43 

-$15.87 

-$1.53 

-$1.47 

-$30.50 

-$31.80 

-$2.83 

-$2.95 

DORMI04 

DORMI06 

$8.75 

$12.64 

$0.81 

$1.17 

-$11.53 

-$14.71 

-$1.07 

-$1.37 

-$14.22 

-$19.24 

-$1.32 

-$1.79 

-$25.36 

-$36.24 

-$2.36 

-$3.37 

HOTEL15 $10.52 $0.98 -$10.78 -$1.00 -$8.72 -$0.81 -$23.24 -$2.16 

HIGHS02 $2.70 $0.25 -$6.04 -$0.56 -$13.56 -$1.26 -$31.76 -$2.95 

OFFIC03 

OFFIC08 

OFFIC16 

$3.66 

$3.24 

$4.37 

$0.34 

$0.30 

$0.41 

-$5.37 

-$6.11 

-$5.29 

-$0.50 

-$0.57 

-$0.49 

-$12.11 

-$6.85 

-$0.66 

-$1.12 

-$0.64 

-$0.06 

-$28.62 

-$23.22 

-$19.41 

-$2.66 

-$2.16 

-$1.80 

RETAIL1 $5.25 $0.49 -$8.03 -$0.75 -$17.71 -$1.65 -$30.07 -$2.79 

RSTRNT1 $6.87 $0.64 -$11.54 -$1.07 -$18.48 -$1.72 -$53.03 -$4.93 

46
 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Arizona 

Table 7-13 reports the statewide changes in total energy costs by building type and 

building design, which account for one year’s worth of new construction evaluated over 

10 years of building operation. The ASHRAE 90.1-2001 design realizes increases in 

energy costs of $14.6 million. ASHRAE 90.1-2004, ASHRAE 90.1-2007, and the LEC 

design realize decreases in energy costs of $20.6 million, $35.5 million, and 

$77.4 million respectively. 

Assuming that the buildings considered in this study, which represent 57.1 % of all new 

commercial floor space in the state, are generally representative of the entire new 

commercial building stock in the state, the results for the ASHRAE 90.1-2001, ASHRAE 

90.1-2004, ASHRAE 90.1-2007, and LEC designs can be extrapolated to estimate 

statewide changes in energy costs of $25.6 million, -$36.1 million, -$62.2 million, 

and -$135.6 million over the 10-year study period, respectively. 

Table 7-13 Statewide Change in Energy Costs for One Year of Construction, 

10-Year, Arizona 

Building Subcategory m 2 ft2 Standard Edition 

Type Weighting (1000s) (1000s) 2001 2004 2007 LEC 

APART04 44.9 % 94 1009 $1 146 574 -$1 202 456 -$1 540 419 -$2 859 098
 

APART06 55.1 % 115 1236 $1 413 648 -$1 477 542 -$1 821 540 -$3 651 187
 

HOTEL15 100.0 % 209 2254 $2 202 478 -$2 258 356 -$1 826 482 -$4 866 383 

HIGHS02 100.0 % 459 4938 $1 678 824 -$2 463 183 -$5 555 403 -$13 131 758 

OFFIC03 37.4 % 302 3248 $814 701 -$1 822 865 -$4 091 443 -$9 581 207 

OFFIC08 40.4 % 325 3502 $1 053 827 -$1 989 078 -$2 227 792 -$7 553 979 

OFFIC16 22.2 % 179 1927 $781 816 -$947 012 -$118 028 -$3 474 105 

RETAIL1 100.0 % 978 10 529 $5 140 291 -$7 852 851 -$17 328 555 -$29 417 748 

RSTRNT1 100.0 % 54 584 $372 720 -$625 865 -$1 002 068 -$2 874 925 

Total 2715 29 227 $14 604 878 -$20 639 206 -$35 511 728 -$77 410 390 

Note: Dormitories are excluded because no such floor area category is reported in the construction data. 

7.2.3 Energy-related Carbon Emissions 

Table 7-14 reports the average reduction in energy-related carbon emissions over 10 

years, per m 

2 (ft2

), by building type and building design. The carbon emissions estimation 

approach is defined in Section 5.3. 

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Arizona 

Table 7-14 Average Per Unit Change in Carbon Emissions, 10-Year, Arizona
 

Building Standard Edition 

Type 2001 

kg/m2 lb/ft2 

2004 

kg/m2 lb/ft2 

2007 

kg/m2 lb/ft2 

LEC 

kg/m2 lb/ft2 

APART04 

APART06 

137.4 28.1 

138.4 28.3 

-143.0 -29.3 

-143.4 -29.4 

-178.6 -36.6 

-173.0 -35.4 

-333.9 -68.4 

-350.1 -71.7 

DORMI04 

DORMI06 

99.1 20.3 

142.6 29.2 

-128.1 -26.2 

-163.7 -33.5 

-153.2 -31.4 

-209.1 -42.8 

-275.5 -56.4 

-397.8 -81.5 

HOTEL15 119.5 24.5 -120.4 -24.7 -93.0 -19.0 -252.7 -51.8 

HIGHS02 42.4 8.7 -60.2 -12.3 -128.7 -26.4 -316.7 -64.9 

OFFIC03 

OFFIC08 

OFFIC16 

30.3 6.2 

35.0 7.2 

49.3 10.1 

-65.8 -13.5 

-66.3 -13.6 

-58.1 -11.9 

-142.4 -29.2 

-72.0 -14.7 

-3.9 -0.8 

-341.0 -69.8 

-249.8 -51.2 

-209.2 -42.9 

RETAIL1 58.6 12.0 -88.2 -18.1 -186.1 -38.1 -321.8 -65.9 

RSTRNT1 77.6 15.9 -127.4 -26.1 -191.8 -39.3 -568.4 -116.4 

Table 7-15 applies the Table 7-14 results to one year’s worth of new building 

construction in the state to estimate statewide reductions in carbon emissions from 

adoption of more energy efficient codes. The total reduction in carbon emissions ranges 

widely across building designs, but the ASHRAE 90.1-2004, ASHRAE 90.1-2007, and 

LEC designs decrease carbon emissions overall. The adoption of ASHRAE 90.1-2004 and 

ASHRAE 90.1-2007 result in savings of 227 670 metric tons and 374 667 metric tons over 

a 10-year study period, respectively. The adoption of the LEC design as the state’s energy 

code decreases carbon emissions by 836 915 metric tons over the 10-year study period 

for one year’s worth of new commercial construction for these building types. Assuming 

that the buildings considered in this study are generally representative of the entire new 

commercial building stock in the state, the results for the ASHRAE 90.1-2004, ASHRAE 

90.1-2007, and LEC design can be extrapolated to estimate statewide reductions in 

carbon emissions of 341 335 metric tons, 561 719 metric tons, and 1.3 million metric tons 

over the 10-year study period, respectively. 

48
 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Arizona 

Table 7-15 Statewide Change in Total Carbon Emissions for One Year of 

Construction, 10-Year, Arizona – Metric Tons 

Building Subcategory m 2 ft2 Standard Edition 

Type Weighting (1000s) (1000s) 2001 2004 2007 LEC 

APART04 44.9 % 94 1009 12 878 -13 404 -16 736 -31 292 

APART06 55.1 % 115 1236 15 885 -16 463 -19 860 -40 189 

HOTEL15 100.0 % 209 2254 25 038 -25 212 -19 475 -52 921 

HIGHS02 100.0 % 459 4938 19 444 -27 609 -59 055 -145 302 

OFFIC03 37.4 % 302 3248 9141 -19 862 -42 950 -102 875 

OFFIC08 40.4 % 325 3502 11 393 -21 561 -23 421 -81 288 

OFFIC16 22.2 % 179 1927 8817 -10 403 -704 -37 459 

RETAIL1 100.0 % 978 10 529 57 326 -86 246 -182 067 -314 772 

RSTRNT1 100.0 % 54 584 4208 -6910 -10 397 -30 816 

Total 2715 29 227 164 131 -227 670 -374 667 -836 915 

Note: Dormitories are excluded because no such floor area category is reported in the 

construction data. 

7.2.4 Life-Cycle Costs 

Table 7-16 reports the average change in life-cycle cost over 10 years, per m2 (ft2

), by 

building type and building design. As discussed in Section 5.2, life-cycle costs include 

construction costs, maintenance, repair, and replacement costs, energy costs, and residual 

values. 

Table 7-16 Average Per Unit Change in Life-Cycle Costs, 10-Year, Arizona 

Building Standard Edition 

Type 2001 

$/m2 $/ft2 

2004 

$/m2 $/ft2 

2007 

$/m2 $/ft2 

LEC 

$/m2 $/ft2 

APART04 $12.96 $1.20 -$12.42 -$1.15 -$17.22 -$1.60 -$15.53 -$1.44 

APART06 $12.77 $1.19 -$12.77 -$1.19 -$16.56 -$1.54 -$16.36 -$1.52 

DORMI04 $46.77 $4.34 $7.56 $0.70 -$1.60 -$0.15 -$14.68 -$1.36 

DORMI06 $14.86 $1.38 -$16.51 -$1.53 -$21.54 -$2.00 -$24.36 -$2.26 

HOTEL15 $14.46 $1.34 -$13.75 -$1.28 -$11.79 -$1.10 -$9.91 -$0.92 

HIGHS02 $6.28 $0.58 -$2.49 -$0.23 -$11.97 -$1.11 -$21.85 -$2.03 

OFFIC03 $37.21 $3.46 $19.44 $1.81 $3.61 $0.34 -$25.83 -$2.40 

OFFIC08 $41.79 $3.88 $18.18 $1.69 $10.92 $1.01 -$19.33 -$1.80 

OFFIC16 $5.40 $0.50 -$4.75 -$0.44 -$0.29 -$0.03 -$0.31 -$0.03 

RETAIL1 $22.85 $2.12 $2.72 $0.25 -$11.49 -$1.07 -$12.12 -$1.13 

RSTRNT1 $79.36 $7.37 $38.47 $3.57 $9.58 $0.89 -$68.94 -$6.41 

Table 7-17 applies the Table 7-16 results to one year’s worth of new building 

construction in the state to estimate statewide changes in life-cycle costs from adoption of 

more energy-efficient state energy codes for commercial buildings. Total changes in 

life-cycle costs over the 10-year study period vary across building designs. Adoption of 

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Arizona 

the ASHRAE 90.1-2001 design results in an increase in life-cycle costs for all 9 building 

types and increases total life-cycle costs by $61.0 million. Adopting the ASHRAE 

90.1-2004 design results in a decrease in life-cycle costs for 5 of 9 building types, and 

increases total life-cycle costs by $9.0 million. Adopting the ASHRAE 90.1-2007 design 

results in a decrease in life-cycle costs for 6 of 9 building types, and decreases total 

life-cycle costs by $17.6 million. The LEC design decreases life-cycle costs for all 9 

building types, and decreases total life-cycle costs by $45.2 million. For a 10-year study 

period, it is cost-effective to adopt the ASHRAE 90.1-2007 and LEC designs as Arizona’s 

state energy code for commercial buildings. Assuming that the buildings considered in 

this study are generally representative of the entire new commercial building stock in the 

state, the results for the adoption of the ASHRAE 90.1-2001, ASHRAE 90.1-2004, 

ASHRAE 90.1-2007, and LEC design can be extrapolated to estimate statewide changes 

in life-cycle costs of $106.9 million, $15.8 million, -$30.8 million, and -$79.1 million 

over the 10-year study period, respectively. 

Table 7-17 Statewide Change in Life-Cycle Costs for One Year of Construction, 

10-Year, Arizona 

Building Subcategory m 2 ft2 Standard Edition 

Type Weighting (1000s) (1000s) 2001 2004 2007 LEC 

APART04 44.9 % 94 1009 $1 215 168 -$1 164 373 -$1 613 730 -$1 455 445
 

APART06 55.1 % 115 1236 $1 465 974 -$1 466 162 -$1 900 827 -$1 878 440
 

HOTEL15 100.0 % 209 2254 $3 027 829 -$2 879 901 -$2 469 988 -$2 075 366 

HIGHS02 100.0 % 459 4938 $2 881 704 -$1 142 843 -$5 490 030 -$10 024 851 

OFFIC03 37.4 % 302 3248 $11 225 261 $5 864 154 $1 090 044 -$7 792 153 

OFFIC08 40.4 % 325 3502 $13 597 461 $5 915 708 $3 552 387 -$6 290 184 

OFFIC16 22.2 % 179 1927 $966 273 -$849 565 -$52 104 -$56 141 

RETAIL1 100.0 % 978 10 529 $22 350 562 $2 656 358 -$11 242 130 -$11 859 954 

RSTRNT1 100.0 % 54 584 $4 302 906 $2 085 725 $519 321 -$3 738 021 

Total 2715 29 227 $61 033 138 $9 019 100 -$17 607 057 -$45 170 554 

Note: Dormitories are excluded because no such floor area category is reported in the construction data. 

7.3 State Summary 

Arizona is one of three states in the West Census Region that have not yet adopted a state 

energy code for commercial buildings. The impacts on individual cities of adopting a 

state energy code vary significantly across cities in the state because some cities have 

adopted local energy codes. On average, adopting ASHRAE 90.1-2004 leads to reductions 

in energy use, energy costs, and cradle-to-grave energy-related carbon emissions, but not 

in a life-cycle cost-effective manner over 10 years. Adopting ASHRAE 90.1-2007 leads to 

greater reductions than adopting ASHRAE 90.1-2004 while decreasing life-cycle costs. 

Based on the average annual new construction in the state from 2003 to 2007 and a 

10-year study period, adopting ASHRAE 90.1-2007 as the state’s energy code for 

50
 
 

 

 

 

 

 

 

Arizona 

commercial buildings would lead to energy use savings of 946.3 GWh (3230.9 GBtu), 

energy cost savings of $62.2 million, and carbon emissions reductions of 561 719 metric 

tons while decreasing life-cycle costs by $30.8 million for one year’s worth of 

commercial building construction. The adoption of the LEC design leads to even greater 

savings of 1.9 TWh (6.3 TBtu) of energy use, $135.6 million of energy costs, 1.3 million 

metric tons of carbon emissions, and $79.1 million of life-cycle costs for one year’s 

worth of commercial building construction. 

51
 
Arizona 

52 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

8 

California 

California 

California has adopted the California Building Standards Code, otherwise known as 

Title 24. California’s state energy code for commercial buildings is assumed to be 

ASHRAE 90.1-2007 for this study because it is the edition of ASHRAE 90.1 that most 

closely correlates to the requirements in Title 24. California is located in the Pacific 

Census Division, and spans five climate zones and seven subzones (Zone 2B, Zone 3B, 

Zone 3C, Zone 4B, Zone 4C, Zone 5B, and Zone 6B). Simulations are run for cities in 

Zone 3B, Zone 3C, and Zone 4C, which are the subzones that cover most of the state and 

contain the most significant population centers in California. Table 8-1 provides an 

overview of California’s simulated energy use keyed to building types and energy codes. 

Average energy use varies across building types and building designs. The 4-story 

dormitory uses the least amount of energy at 59 kWh/m2 to 71 kWh/m2 (19 kBtu/ft2 to 

23 kBtu/ft2

) annually. The restaurant uses the greatest amount of energy for the ASHRAE 

90.1-1999 design at 125 kWh/m2 (40 kBtu/ft2) annually. The high school uses the 

greatest amount of energy for the LEC design at 108 kWh/m2 (34 kBtu/ft2) annually. 

Table 8-1 Average Annual Energy Use by Building Type and Standard Edition, 

California 

Building 

Type 

Standard Edition 

2007 

kWh/m2 kBtu/ft2 

LEC 

kWh/m2 kBtu/ft2 

APART04 

APART06 

96 31 

97 31 

81 26 

79 25 

DORMI04 

DORMI06 

71 23 

105 33 

59 19 

86 27 

HOTEL15 98 31 81 26 

HIGHS02 124 39 108 34 

OFFIC03 

OFFIC08 

OFFIC16 

92 29 

92 29 

115 36 

69 22 

73 23 

92 29 

RETAIL1 92 29 77 24 

RSTRNT1 125 40 83 26 

The detailed analysis for this state reports the changes in energy use, energy costs, 

energy-related carbon emissions, and life-cycle costs from adoption of the LEC design. 

The results are reported in terms of average percentage savings on a statewide and 

city-by-city basis and as total savings on a statewide basis. 

8.1 Percentage Savings 

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California 

Changes in percentage terms allow for direct comparisons across building types and 

locations within a state. This section discusses the average percentage changes from 

investing in the LEC design in the state of California. 

8.1.1 Statewide Building Comparison 

Table 8-2 shows the percentage changes in energy use, energy costs, energy-related
 

carbon emissions, and life-cycle costs for the LEC design relative to ASHRAE 90.1-2007.
 

There is significant variation in the change in energy use, ranging from -13.7 %
 

to -34.1 % depending on the building type with an overall average of -19.8 %. High
 

schools realize the lowest reduction in energy use while restaurants realize the greatest
 

reduction in energy use.
 

Table 8-2 Average Percentage Change from Adoption of Newer Standard Editions, 

10-Year, California 

Building LEC 

Type Energy Use Energy Cost Carbon LCC 

APART04 -16.1 -22.5 -19.8 0.2 

APART06 -18.2 -26.1 -22.8 -0.1 

DORMI04 -18.2 -22.3 -20.6 -1.3 

DORMI06 -17.9 -26.3 -22.7 -0.4 

HOTEL15 -18.2 -24.5 -21.8 0.0 

HIGHS02 -13.7 -23.4 -19.2 -1.8 

OFFIC03 -24.5 -25.5 -25.1 -3.0 

OFFIC08 -21.4 -21.9 -21.8 -2.8 

OFFIC16 -19.8 -21.8 -21.0 -0.1 

RETAIL1 -16.1 -17.8 -17.1 -0.0 

RSTRNT1 -34.1 -37.5 -36.2 -5.2 

Average -19.8 -24.5 -22.6 -1.3 

There is a significant variation in the average percentage change in energy costs for the 

LEC design relative to ASHRAE 90.1-2007, ranging from -17.8 % to -37.5 % depending 

on the building type with an average of -24.5 % for 10 years of building operation. The 

energy costs are reduced by a greater percentage than energy use because the energy 

efficiency measures decrease electricity consumption by a greater percentage than natural 

gas consumption. In fact, adopting the LEC design leads to an increase in natural gas 

consumption and a decrease in electricity consumption for all 11 building types. The shift 

is most prevalent for the high school, where the increase in natural gas consumption 

offsets 34.4 % of the reduction in electricity consumption, and results in a percentage 

reduction in energy costs that is 1.7 times the percentage reduction in energy use. The 

LEC design incorporates daylighting and overhangs into the building design for cities in 

Zone 2 through Zone 5, which decreases the building’s internal and external heat gains, 

respectively. The shift in energy use from electricity to natural gas consumption to meet 

54
 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

California 

the greater heating loads decreases energy costs because natural gas is cheaper on a per 

unit of energy basis relative to electricity. 

There is significant variation in the average change in energy-related carbon emissions 

across building types for the LEC design relative to ASHRAE 90.1-2007, ranging 

from -17.1 % to -36.2 % with an average of -22.6 %. As mentioned above, the energy 

efficiency measures decrease electricity consumption while increasing natural gas 

consumption for all 11 building types. The combination of the reduction in total energy 

use and the shift in energy use from electricity consumption to natural gas consumption 

leads to greater reductions in carbon emissions than reductions in energy use. 

The percentage change in life-cycle costs varies across building types, ranging 

from -5.2 % to 0.2 % for a 10-year study period. Nine of the 11 building types realize 

reductions in life-cycle costs. Based on the overall average percentage change of -1.3 % 

in life-cycle costs, the LEC design may be cost-effective if the state adopted it as its state 

energy code for commercial buildings. 

8.1.2 City Comparisons 

Simulations are run for eleven cities located in California: Bakersfield, Daggett, Fresno, 

Long Beach, Los Angeles, Riverside, Sacramento, and San Diego in Zone 3B, San 

Francisco and Santa Maria in Zone 3C, and Arcata in Zone 4B. There are no significant 

population centers in the counties of California located in Zone 2B, Zone 3B, Zone 5B, 

and Zone 6B. The results vary across cities within the state for several reasons. First, the 

cities in the state selected for this study cover three climate subzones. The ASHRAE 90.1 

building design requirements vary across climate zones and will impact the relative 

energy efficiency of the building. Second, cities within the same climate zone still have 

some variation in the local climate, which can lead to variation in energy consumption. 

Third, construction material and labor costs vary by locality. 

Table 8-3 shows the percentage changes in energy use, energy costs, energy-related 

carbon emissions, and life-cycle costs for the LEC design relative to ASHRAE 90.1-2007 

for each city in the state. The average percentage changes in energy use for all building 

types from adopting the LEC design vary across cities, ranging from -14.3 % to -24.4 % 

with an overall average of -19.8 %. There is significant variation across climate subzones, 

with cities in Zone 3B realizing greater average percentage reductions in energy use 

(21.1 %) compared to Zone 3C (17.5 %) and Zone 4B (14.3 %). There is also significant 

variation between cities within Zone 3B, ranging from 17.7 % to 25.1 %. The further 

north and inland a city is located, the smaller the percentage reduction in energy use. 

55
 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

California 

Table 8-3 Average Percentage Change from Adoption of Newer Standard Editions 

by City, 10-Year, California 

Cities Zone LEC 

Energy Use Energy Cost Carbon LCC 

Bakersfield 3B -19.1 -22.8 -21.6 -1.4 

Daggett 3B -20.1 -23.0 -22.1 -1.4 

Fresno 3B -18.1 -23.0 -21.2 -1.6 

Long Beach 3B -23.8 -25.9 -25.4 -1.4 

Los Angeles 3B -24.4 -26.5 -26.0 -1.6 

Riverside 3B -20.7 -24.8 -23.4 -1.8 

Sacramento 3B -17.7 -23.4 -21.2 -1.4 

San Diego 3B -25.1 -26.3 -26.1 -1.4 

San Francisco 3C -17.2 -24.6 -21.4 -0.3 

Santa Maria 3C -17.8 -25.4 -22.2 -0.9 

Arcata 4B -14.3 -23.9 -19.4 -1.2 

Average -19.8 -24.5 -22.7 -1.3 

The average percentage change in energy costs for all building types also varies across 

cities, ranging from -22.8 % to -26.5 % for 10 years of operation. For all cities, 

reductions in energy costs are greater than reductions in energy use because the 

percentage reduction in electricity consumption is greater than the reduction in natural 

gas consumption. Repeating the pattern, the average percentage change in carbon 

emissions for all building types also varies across cities, ranging from -19.4 % 

to -26.1 %. Changes in life-cycle costs for all building types vary across cities, with the 

percentage change in life-cycle costs ranging from -1.8 % to -0.3 %. Cities located in 

Zone 3B realize the greatest percentage reductions in life-cycle costs while cities in 

Zone 3C realize the smallest percentage reductions. 

8.2 Total Savings 

How much can California save, in terms of energy use, energy costs, and carbon 

emissions, from adopting a more stringent state energy code for commercial buildings? 

What are the life-cycle costs associated with the new energy code adoption? To answer 

these questions, it is necessary to estimate savings per unit of floor area for each building 

type in the state. 

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California 

8.2.1 Energy Use 

Table 8-4 reports the average per unit change in annual energy use by building type and 

building design in the state.20 The reduction per m2 (ft2

) is multiplied by the estimated m2 

(ft2) of new construction of each building type, and Table 8-5 reports the estimated 

average annual floor area of new construction and the total annual reduction in energy 

use for each building type. The weightings within a category (e.g., small, medium, and 

large office buildings) are based on the national average percentage of new building 

construction for the category that is represented by each subcategory.21 

Table 8-4 Average Per Unit Change in Annual Energy Use, California 

Building Standard Edition 

Type LEC 

kWh/m2 kBtu/ft2 

APART04 -15.4 -4.9 

APART06 -17.6 -5.6 

DORMI04 -12.9 -4.1 

DORMI06 -18.5 -5.9 

HOTEL15 -17.5 -5.6 

HIGHS02 -22.4 -7.1 

OFFIC03 -16.0 -5.1 

OFFIC08 -19.8 -6.3 

OFFIC16 -22.6 -7.2 

RETAIL1 -14.9 -4.7 

RSTRNT1 -42.5 -13.5 

The adoption of the LEC design as the state’s energy code for commercial buildings 

would save energy for all building types and 141.7 GWh (483.7 GBtu) of total energy use 

annually for one year’s worth of new construction for these building types. Assuming that 

the buildings considered in this study, which represent 55.7 % of all new commercial 

floor space in the state, are generally representative of the entire new commercial 

building stock in the state, the results can be extrapolated to estimate statewide savings to 

be 254.3 GWh (868.4 GBtu) per year. These savings imply 2.5 TWh (8.7 TBtu) in energy 

use savings over the 10-year study period. 

The change in energy use varies across building types. The building types that have the 

greatest percentage reductions are not always the same buildings that lead to the greatest 

total reductions for the state. The greatest total reductions are realized by retail stores and 

high schools because they represent 26.3 % and 17.6 %, respectively, of the combined 

new construction in the state for the building types in this study while all other building 

20 A simple average for a state is used because no data for a weighted average is available regarding the
 

amount of new construction on a city-by-city basis.
 

21 State-level subcategory data are not available.
 

57
 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

California 

types represent 13.3 % or less. The amount of new construction overwhelms the relative 

percentage changes in energy use. The building types that lead to the greatest estimated 

reductions in energy use for the LEC design -- retail stores and high schools -- only rank 

10th and 11th in percentage reduction, respectively, among the 11 building types, as 

reported in Table 8-2. 

Table 8-5 Statewide Change in Annual Energy Use for One Year of Construction, 

California 

Building Subcategory m 2 ft2 Standard Edition 

Type Weighting (1000s) (1000s) LEC 

kWh kBtu 

APART04 44.9 % 877 9445 -13 551 088 -46 269 240
 

APART06 55.1 % 1075 11 569 -18 892 097 -64 505 744
 

HOTEL15 100.0 % 626 6736 -10 971 677 -37 462 024 

HIGHS02 100.0 % 1417 15 252 -22 659 386 -77 368 888 

OFFIC03 37.4 % 690 7428 -15 485 457 -52 874 008 

OFFIC08 40.4 % 744 8010 -14 719 305 -50 258 035 

OFFIC16 22.2 % 409 4407 -9 264 539 -31 633 118 

RETAIL1 100.0 % 2125 22 869 -31 580 788 -107 830 389 

RSTRNT1 100.0 % 107 1149 -4 534 187 -15 481 663 

Total 8070 86 866 -141 658 523 -483 683 109 

Note: Dormitories are excluded because no such floor area category is reported 

in the construction data. 

8.2.2 Energy Costs 

Table 8-6 reports the average per unit change in energy costs by building type for the 

LEC design. Energy costs are calculated using the annual energy use, state average 

energy cost rates, and regional energy price escalation rates as defined in Section 3.2. 

58
 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

California 

Table 8-6 Average Per Unit Change in Energy Costs, 10-Year, California
 

Building Standard Edition 

Type LEC 

$/m2 $/ft2 

APART04 -$19.20 -$1.78 

APART06 -$22.50 -$2.09 

DORMI04 -$14.88 -$1.38 

DORMI06 -$24.01 -$2.23 

HOTEL15 -$20.78 -$1.93 

HIGHS02 -$24.14 -$2.24 

OFFIC03 -$24.20 -$2.25 

OFFIC08 -$21.18 -$1.97 

OFFIC16 -$24.75 -$2.30 

RETAIL1 -$16.25 -$1.51 

RSTRNT1 -$45.36 -$4.21 

Table 8-7 reports the statewide changes in total energy costs by building type and 

building design, which account for one year’s worth of new construction evaluated over 

10 years. All building types realize energy cost savings for the LEC design, with a 

statewide reduction in energy costs of $170.2 million for 10 years of building operation. 

Assuming that the buildings considered in this study, which represent 55.7 % of all new 

commercial floor space in the state, are generally representative of the entire new 

commercial building stock in the state, the results for the LEC design can be extrapolated 

to estimate the total statewide energy cost savings of $305.6 million over the 10-year 

study period. 

Table 8-7 Statewide Change in Energy Costs for One Year of Construction, 

10-Year, California 

Building Subcategory m 2 ft2 Standard Edition
 

Type Weighting (1000s) (1000s)
 LEC 

APART04 44.9 % 877 9445 -$16 848 968 

APART06 55.1 % 1075 11 569 -$24 182 352 

HOTEL15 100.0 % 626 6736 -$13 002 075 

HIGHS02 100.0 % 1417 15 252 -$34 288 714 

OFFIC03 37.4 % 690 7428 -$16 656 170 

OFFIC08 40.4 % 744 8010 -$15 759 279 

OFFIC16 22.2 % 409 4407 -$10 132 012 

RETAIL1 100.0 % 2125 22 869 -$34 518 887 

RSTRNT1 100.0 % 107 1149 -$4 843 949 

Total 8070 86 866 -$170 232 407 

Note: Dormitories are excluded because no such floor area category is 

reported in the construction data. 

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California 

8.2.3 Energy-related Carbon Emissions 

Table 8-8 reports the average reduction in energy-related carbon emissions over 10 years, 

per m 2 (ft2

), by building type. The carbon emissions estimation approach is defined in 

Section 5.3. 

Table 8-8 Average Per Unit Change in Carbon Emissions, 10-Year, California 

Building Standard Edition 

Type LEC 

kg/m2 lb/ft2 

APART04 -85.2 -17.5 

APART06 -98.9 -20.3 

DORMI04 -67.7 -13.9 

DORMI06 -105.1 -21.5 

HOTEL15 -93.7 -19.2 

HIGHS02 -101.1 -20.7 

OFFIC03 -112.6 -23.1 

OFFIC08 -99.0 -20.3 

OFFIC16 -114.8 -23.5 

RETAIL1 -75.4 -15.4 

RSTRNT1 -212.2 -43.5 

Table 8-9 applies the Table 8-8 results to one year’s worth of new building construction 

in the state to estimate the statewide reduction in carbon emissions from adoption of the 

LEC design. The total reduction in carbon emissions ranges widely across building 

designs and is highly correlated with the total reduction in energy use. The LEC design 

decreases carbon emissions for all building types. The adoption of the LEC design results 

in savings of 764 202 metric tons over the 10-year study period for one year’s worth of 

new commercial construction for these building types. Assuming that the buildings 

considered in this study are generally representative of the entire new commercial 

building stock in the state, the results for the LEC design can be extrapolated to estimate 

statewide reductions in carbon emissions of 1.4 million metric tons over the 10-year 

study period. 

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California 

Table 8-9 Statewide Change in Total Carbon Emissions for One Year of 

Construction, 10-Year, California – Metric Tons 

Building Subcategory m 2 ft2 Standard Edition
 

Type Weighting (1000s) (1000s)
 LEC 

APART04 44.9 % 877 9445 -74 788 

APART06 55.1 % 1075 11 569 -106 330 

HOTEL15 100.0 % 626 6736 -58 644 

HIGHS02 100.0 % 1417 15 252 -143 296 

OFFIC03 37.4 % 690 7428 -77 714 

OFFIC08 40.4 % 744 8010 -73 652 

OFFIC16 22.2 % 409 4407 -46 992 

RETAIL1 100.0 % 2125 22 869 -160 131 

RSTRNT1 100.0 % 107 1149 -22 656 

Total 8070 86 866 -764 202 

Note: Dormitories are excluded because no such floor area category is 

reported in the construction data. 

8.2.4 Life-Cycle Costs 

Table 8-10 reports the average change in life-cycle cost over 10 years, per m2 (ft2), by 

building type. As discussed in Section 5.2, life-cycle costs include construction costs, 

maintenance, repair, and replacement costs, energy costs, and residual values. 

Table 8-10 Average Per Unit Change in Life-Cycle Costs, 10-Year, California 

Building Standard Edition 

Type LEC 

$/m2 $/ft2 

APART04 $2.70 $0.25 

APART06 -$0.56 -$0.05 

DORMI04 -$14.00 -$1.30 

DORMI06 -$4.84 -$0.45 

HOTEL15 $0.37 $0.03 

HIGHS02 -$16.50 -$1.53 

OFFIC03 -$27.64 -$2.57 

OFFIC08 -$27.10 -$2.52 

OFFIC16 -$1.01 -$0.09 

RETAIL1 -$0.15 -$0.01 

RSTRNT1 -$77.09 -$7.16 

Table 8-11 applies the Table 8-10 results to one year’s worth of new building 

construction in the state to estimate statewide changes in life-cycle costs from adoption of 

the LEC design. Total changes in life-cycle costs over the 10-year study period vary 

across building type, with 7 of 9 building types realizing reductions in life-cycle costs. 

Overall, the LEC design results in a decrease of $69.6 million in statewide life-cycle 

61
 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

California 

costs relative to ASHRAE 90.1-2007. High schools, 8-story office buildings, and 3-story 

office buildings realize the greatest statewide decreases in life-cycle costs ($23.4 million, 

$20.2 million, and $19.1 million, respectively) while 4-story apartment buildings and 

hotels realize an increase in life-cycle costs ($2.4 million and $231 526, respectively). 

Assuming that the buildings considered in this study are generally representative of the 

entire new commercial building stock in the state, the results for the LEC design can be 

extrapolated to estimate a decrease in statewide life-cycle costs of $124.9 million over the 

10-year study period. 

Table 8-11 Statewide Change in Life-Cycle Costs for One Year of Construction, 

10-Year, California 

Building Subcategory m 2 ft2 Standard Edition
 

Type Weighting (1000s) (1000s) LEC
 

APART04 44.9 % 877 9445 $2 372 624 

APART06 55.1 % 1075 11 569 -$598 745 

HOTEL15 100.0 % 626 6736 $231 526 

HIGHS02 100.0 % 1417 15 252 -$23 376 695 

OFFIC03 37.4 % 690 7428 -$19 075 494 

OFFIC08 40.4 % 744 8010 -$20 170 590 

OFFIC16 22.2 % 409 4407 -$415 565 

RETAIL1 100.0 % 2125 22 869 -$320 656 

RSTRNT1 100.0 % 107 1149 -$8 231 538 

Total 8070 86 866 -$69 585 133 

Note: Dormitories are excluded because no such floor area category is 

reported in the construction data. 

8.3 State Summary 

ASHRAE 90.1-2007 is used to represent California’s state energy code for commercial 

buildings (Title 24). On average, adopting the LEC design reduces energy use, energy 

costs, and energy-related carbon emissions, and does so in a cost-effective manner. Based 

on the average annual new construction in the state from 2003 to 2007 and a 10-year 

study period, adopting the LEC design as the state’s energy code for commercial 

buildings would lead to statewide energy use savings of 2.5 TWh (8.7 TBtu), energy cost 

savings of $305.6 million, and carbon emissions reductions of 1.4 million metric tons 

while decreasing life-cycle costs by $124.9 million for one year’s worth of commercial 

building construction. 

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9 

Colorado 

Colorado 

Colorado is the only state in the West Census Region that has adopted ASHRAE 

90.1-2001 as its state energy code for commercial buildings, is located in the Mountain 

Census Division, and spans four climate zones (Zone 4B, Zone 5B, Zone 6B, and Zone 

7). Table 9-1 provides an overview of Colorado’s simulated energy use keyed to building 

types and energy standard editions. Average energy use varies across building types and 

building designs. The 8-story office building uses the least amount of energy at 80 

kWh/m2 to 113 kWh/m2 (25 kBtu/ft2 to 36 kBtu/ft2

) annually. The high school uses the 

greatest amount of energy at 203 kWh/m2 to 228 kWh/m2 (65 kBtu/ft2 to 72 kBtu/ ft2

) 

annually. 

Table 9-1 Average Annual Energy Use by Building Type and Standard Edition, 

Colorado 

Building 

Type 

Standard Edition 

2001 

kWh/m2 kBtu/ft2 

2004 

kWh/m2 kBtu/ft2 

2007 

kWh/m2 kBtu/ft2 

LEC 

kWh/m2 kBtu/ft2 

APART04 

APART06 

163 52 

160 51 

145 46 

141 45 

139 44 

136 43 

124 39 

121 38 

DORMI04 

DORMI06 

128 41 

175 56 

114 36 

156 50 

108 34 

153 49 

93 30 

136 43 

HOTEL15 158 50 142 45 149 47 130 41 

HIGHS02 228 72 224 71 216 69 203 65 

OFFIC03 

OFFIC08 

OFFIC16 

120 38 

113 36 

149 47 

112 35 

103 33 

139 44 

105 33 

99 31 

148 47 

84 27 

80 25 

124 39 

RETAIL1 145 46 134 42 119 38 102 32 

RSTRNT1 201 64 185 59 161 51 118 37 

The detailed analysis for this state reports the changes in energy use, energy costs, 

energy-related carbon emissions, and life-cycle costs from adoption of increasingly 

stringent energy codes. The results are reported in terms of average percentage savings on 

a statewide and city-by-city basis and as total savings on a statewide basis. 

9.1 Percentage Savings 

Changes in percentage terms allow for direct comparisons across building types and 

locations within a state. This section discusses the average percentage changes from 

investing in more energy efficient designs for the state of Colorado. 

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9.1.1 Energy Use 

Table 9-2 shows that the average percentage changes in energy use from adopting the 

ASHRAE 90.1-2004 design relative to ASHRAE 90.1-2001 range from -1.4 % to -9.1 % 

depending on the building type, with an overall average of -6.9 %. The average 

percentage change in energy use from constructing buildings using ASHRAE 90.1-2007 

requirements ranges from 0.3 % to -18.6 %, with an overall average of -10.4 %. 

Table 9-2 Average Percentage Change in Energy Use from Adoption of Newer 

Standard Editions, Colorado 

Building Standard Edition 

Type 2004 2007 LEC 

APART04 -8.8 -12.7 -21.9 

APART06 -9.1 -12.4 -22.5 

DORMI04 -8.3 -13.4 -24.9 

DORMI06 -9.0 -10.6 -20.7 

HOTEL15 -8.3 -3.4 -16.0 

HIGHS02 -1.4 -5.0 -10.6 

OFFIC03 -5.6 -11.3 -29.3 

OFFIC08 -7.5 -10.7 -28.3 

OFFIC16 -5.3 0.3 -15.7 

RETAIL1 -6.5 -17.1 -28.4 

RSTRNT1 -6.4 -18.6 -40.2 

Average -6.9 -10.4 -23.5 

For the high-rise, 100 % glazed buildings (16-story office building and 15-story hotel), 

ASHRAE 90.1-2004 is actually more energy efficient than ASHRAE 90.1-2007 because 

the maximum allowable window SHGC in Zone 5 and Zone 6 is increased from ASHRAE 

90.1-2004 to ASHRAE 90.1-2007 for buildings with fenestration accounting for greater 

than 40 % of total wall surface area. The 100 % glazing amplifies the impact of this 

requirement relaxation enough to overwhelm the energy efficiency gains obtained from 

other measures, such as increased insulation R-values. 

The LEC design realizes the greatest percentage change in energy use relative to 

ASHRAE 90.1-2001, with a range of -10.6 % to -40.2 % and an overall average 

of -23.5 %. Similar to the ASHRAE 90.1-2007 design, smaller reductions in energy use 

for the LEC design occur in the buildings with the greatest window-to-wall ratios. The 

smallest percentage reduction is realized by the high school because of its occupancy 

pattern. Schools are used primarily during the school year with minimal use during the 

summer. Since some of the additional energy efficiency measures (daylighting and 

overhangs) adopted in the LEC design reduce solar heat gains, cooling loads are 

decreased while heating loads are increased. The increase in heating loads is greater than 

the reduction in cooling loads because the building has a low occupancy during the 

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warmest months of the year and the Colorado climate requires significant heating during 

the coldest months. 

9.1.2 Energy Costs 

Table 9-3 shows a significant variation in the average change in energy costs over 10 

years of operation from adopting the ASHRAE 90.1-2004 design relative to ASHRAE 

90.1-2001, ranging from -6.3 % to -19.8 % depending on the building type, with an 

overall average of -14.1 %. The average change in energy costs from constructing 

buildings using ASHRAE 90.1-2007 requirements ranges from -2.4 % to -22.0 %, with an 

overall average of -15.2 %. As with energy use savings, adopting ASHRAE 90.1-2004 

results in greater reductions in energy costs than adopting ASHRAE 90.1-2007 for the two 

high rise buildings (16-story office building and 15-story hotel) because of the 100 % 

glazing in the buildings and the relaxed window SHGC requirements. 

Table 9-3 Average Percentage Change in Energy Costs, 10-Year, Colorado 

Building Standard Edition 

Type 2004 2007 LEC 

APART04 -19.6 -22.0 -36.2 

APART06 -19.8 -21.7 -37.7 

DORMI04 -19.5 -21.8 -36.6 

DORMI06 -19.7 -20.6 -36.0 

HOTEL15 -18.4 -12.8 -28.8 

HIGHS02 -6.3 -8.8 -23.1 

OFFIC03 -8.8 -10.9 -32.1 

OFFIC08 -9.7 -10.6 -29.7 

OFFIC16 -9.1 -2.4 -21.2 

RETAIL1 -11.7 -17.3 -32.0 

RSTRNT1 -12.5 -18.8 -46.3 

Average -14.1 -15.2 -32.7 

The LEC design realizes the greatest percentage changes in energy costs, with the 

average reduction by building type ranging from -23.1 % to -46.3 % and an overall 

average of -32.7 %. The reductions in energy costs are greater than the reductions in 

energy use because the adopted energy efficiency measures decrease electricity 

consumption by a greater percentage than natural gas consumption. The greater relative 

reduction in electricity consumption further decreases energy costs because natural gas is 

cheaper per unit of energy than electricity in Colorado. 

9.1.3 Energy-related Carbon Emissions 

Table 9-4 shows significant changes in average energy-related carbon emissions for 

ASHRAE 90.1-2004 for all building types, ranging from -7.0 % to -21.1 % with an 

average of -15.0 % overall. The average change in carbon emissions from constructing 

buildings using ASHRAE 90.1-2007 requirements is -15.8 % overall with the average 

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change in carbon emissions varying across building types from -2.7 % to -23.1 %. The 

LEC design leads to the greatest average percentage changes in carbon emissions, 

ranging from -21.7 % to -47.0 % depending on the building type with an overall average 

of -33.8 % across all building types. 

Table 9-4 Average Percentage Change in Energy-related Carbon Emissions, 10­

Year, Colorado 

Building Standard Edition 

Type 2004 2007 LEC 

APART04 -21.0 -23.1 -37.9 

APART06 -21.1 -22.8 -39.5 

DORMI04 -20.8 -22.8 -37.9 

DORMI06 -21.0 -21.8 -37.9 

HOTEL15 -19.6 -13.9 -30.3 

HIGHS02 -7.0 -9.3 -25.0 

OFFIC03 -9.2 -10.9 -32.4 

OFFIC08 -9.9 -10.6 -29.9 

OFFIC16 -9.5 -2.7 -21.7 

RETAIL1 -12.3 -17.3 -32.4 

RSTRNT1 -13.2 -18.8 -47.0 

Average -15.0 -15.8 -33.8 

As would be expected, a more energy efficient building design results in greater 

reductions in carbon emissions. However, the percentage reduction in carbon emissions is 

greater than the percentage reduction in energy use because the percentage reduction in 

electricity consumption is greater than the reduction in natural gas consumption. Since 

electricity production in Colorado generates greater emissions per unit of energy 

consumed than natural gas, the greater relative reduction in electricity leads to a greater 

reduction in carbon emissions. 

9.1.4 Life-Cycle Costs 

The most cost-effective building design for each building type is bolded in Table 9-5. 

The ASHRAE 90.1-2004, ASHRAE 90.1-2007, and LEC designs realize the lowest lifecycle costs for one, five, and five building types, respectively. Both ASHRAE 90.1-2004 

and ASHRAE 90.1-2007 realize lower life-cycle costs than ASHRAE 90.1-2001 for all 11 

building types. The LEC design results in significant reductions in life-cycle costs for 10 

of 11 building types. The change in life-cycle costs for the LEC design ranges 

from -7.4 % to 0.1 %. Based on the overall average change of -2.8 % in life-cycle costs, 

the LEC design is likely to be cost-effective if the state adopted it as its state energy code 

for commercial buildings. 

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Table 9-5 Average Percentage Change in Life-Cycle Costs, 10-Year, Colorado
 

Building Standard Edition 

Type 2004 2007 LEC 

APART04 -1.6 -1.9 -1.2 

APART06 -1.5 -1.8 -1.2 

DORMI04 -2.4 -2.9 -4.2 

DORMI06 -2.0 -2.1 -1.8 

HOTEL15 -2.1 -1.6 -1.1 

HIGHS02 -0.8 -1.1 -1.9 

OFFIC03 -2.3 -2.6 -5.5 

OFFIC08 -2.3 -2.6 -5.1 

OFFIC16 -1.0 -0.3 0.1 

RETAIL1 -2.1 -2.9 -2.0 

RSTRNT1 -2.5 -4.5 -7.4 

Average -1.9 -2.2 -2.8 

9.1.5 City Comparisons 

Simulations are run for 6 cities located in Colorado: Boulder, Colorado Springs, Grand 

Junction, and Pueblo in Climate Zone 5B and Alamosa and Eagle in Climate Zone 6B. 

Colorado has no significant population centers located Zone 4B or Zone 7. The results 

vary across cities within the state for several reasons. First, the cities selected for this 

study span two climate zones. The ASHRAE 90.1 building design requirements vary 

across climate zones and will impact the relative energy efficiency of the building. 

Second, cities within the same climate zone still have some variation in the local climate, 

which can lead to variation in energy consumption. Third, construction material and labor 

costs vary by locality. Finally, Grand Junction has adopted a stricter building energy code 

than has the state (ASHRAE 90.1-2004). 

As can be seen in Table 9-6, the average percentage reduction in energy use for all 

building types from adopting newer energy standard editions is generally greater for the 

cities located in Zone 5. For the LEC design, Zone 5 excluding Grand Junction realizes 

an average change in energy use of -25.8 % compared to -22.5 % for Zone 6. Grand 

Junction realizes much lower reductions in energy use for the ASHRAE 90.1-2007 and 

LEC designs because it has already adopted ASHRAE 90.1-2004 as its jurisdictional 

energy code. 

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Colorado 

Table 9-6 Average Percentage Change in Energy Use from Adoption of Newer 

Standard Editions by City, Colorado 

Cities Zone Standard Edition 

2004 2007 LEC 

Boulder 5B -9.4 -12.5 -25.5 

Colorado Springs 5B -9.2 -12.4 -24.9 

Grand Junction 5B 0.0 -3.2 -17.9 

Pueblo 5B -10.5 -13.2 -27.3 

Alamosa 6B -6.6 -11.0 -23.1 

Eagle 6B -5.9 -10.3 -22.2 

Average -6.9 -10.4 -23.5 

The variations in energy cost changes across cities are a result of two factors, the size of 

the reductions in energy use and the fuel source of the reduction. Table 9-7 shows that the 

average reduction in energy costs for all building types is similar across both Zone 5 and 

Zone 6 for both ASHRAE 90.1-2004 and ASHRAE 90.1-2007 if Grand Junction is 

excluded from the analysis. The LEC design realizes nearly twice the percentage 

reduction in energy costs than ASHRAE 90.1-2007, with Zone 5 cities excluding Grand 

Junction realizing an average change in energy costs of -35.7 % compared to -33.2 % for 

Zone 6. The reductions in energy costs are significantly greater than the reductions in 

energy use because the percentage reduction in electricity consumption is greater than the 

reduction in natural gas consumption. Since Grand Junction has already adopted 

ASHRAE 90.1-2004, it realizes much smaller changes in energy costs for the ASHRAE 

90.1-2007 and LEC designs. 

Table 9-7 Average Percentage Change in Energy Costs by City, 10-Year, Colorado 

Cities Zone Standard Edition 

2004 2007 LEC 

Boulder 5B -16.8 -17.6 -35.6 

Colorado Springs 5B -16.9 -17.8 -35.4 

Grand Junction 5B 0.0 -1.1 -22.6 

Pueblo 5B -16.9 -17.7 -36.1 

Alamosa 6B -17.3 -18.9 -33.5 

Eagle 6B -16.7 -18.3 -32.9 

Average -14.1 -15.2 -32.7 

Table 9-8 reports changes in energy-related carbon emissions by city for the state. For all 

cities, the more energy efficient building designs result in greater reductions in carbon 

emissions. As with energy use, the cities in Zone 6 realize slightly lower average 

emission reductions than the cities in Zone 5 (excluding Grand Junction) for all building 

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designs. For both climate zones, adopting the ASHRAE 90.1-2007 and ASHRAE 

90.1-2004 designs would decrease energy-related carbon emissions on average. The LEC 

design realizes the greatest percentage reductions in carbon emissions, with the average 

percentage reduction ranging from -23.8 % to -37.1 % depending on the location. 

Table 9-8 Average Percentage Change in Carbon Emissions by City, 10-Year, 

Colorado 

Cities Zone Standard Edition 

2004 2007 LEC 

Boulder 5B -17.0 -18.0 -36.7 

Colorado Springs 5B -17.1 -18.1 -36.6 

Grand Junction 5B 0.0 -1.3 -23.8 

Pueblo 5B -16.9 -17.9 -37.1 

Alamosa 6B -17.9 -19.5 -34.7 

Eagle 6B -17.3 -19.0 -34.2 

Average -15.0 -15.8 -33.8 

The data reported in Table 9-9 show that, over a 10-year period, the LEC design results in 

the lowest average life-cycle costs for all cities in both Zone 5 and Zone 6. Reductions in 

life-cycle costs are similar across all cities in the state except for Grand Junction, which 

realizes much smaller cost reductions because the city has adopted ASHRAE 90.1-2004. 

Life-cycle costs are reduced by adopting ASHRAE 90.1-2004 or ASHRAE 90.1-2007 

relative to ASHRAE 90.1-2001 for all cities, on average. 

Table 9-9 Average Percentage Change in Life-Cycle Costs by City, 10-Year, 

Colorado 

Cities Zone Standard Edition 

2004 2007 LEC 

Boulder 5B -2.1 -2.4 -2.9 

Colorado Springs 5B -2.1 -2.4 -2.9 

Grand Junction 5B 0.0 -0.4 -1.7 

Pueblo 5B -2.2 -2.6 -3.6 

Alamosa 6B -2.5 -2.8 -3.1 

Eagle 6B -2.4 -2.7 -2.9 

Average -1.9 -2.2 -2.8 

9.2 Total Savings 

How much can Colorado save, in terms of energy use, energy costs, and carbon 

emissions, from adopting a more stringent state energy code for commercial buildings? 

What are the life-cycle costs associated with the new energy code adoption? To answer 

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these questions, it is necessary to estimate savings per unit of floor area for each building 

type in the state. 

9.2.1 Energy Use 

Table 9-10 reports the average per unit change in annual energy use by building type and 

building design in the state.22 The reduction per m2 (ft2

) is multiplied by the estimated 

annual m2 (ft2) of new construction of each building type, and Table 9-11 reports the 

estimated average annual floor area of new construction and the total annual reduction in 

energy use for each building type. The weightings within a category (e.g., small, medium, 

and large office buildings) are based on the national average percentage of new building 

construction for the category that is represented by each subcategory.23 

Table 9-10 Average Per Unit Change in Annual Energy Use, Colorado 

Building Standard Edition 

Type 2004 

kWh/m2 kBtu/ft2 

2007 

kWh/m2 kBtu/ft2 

LEC 

kWh/m2 kBtu/ft2 

APART04 -14.1 -4.5 -20.4 -6.5 -35.0 -11.1 

APART06 -14.3 -4.5 -19.5 -6.2 -35.1 -11.1 

DORMI04 -10.4 -3.3 -16.7 -5.3 -31.1 -9.9 

DORMI06 -15.7 -5.0 -18.5 -5.9 -35.6 -11.3 

HOTEL15 -13.0 -4.1 -5.5 -1.7 -24.8 -7.9 

HIGHS02 -6.7 -2.1 -13.4 -4.3 -34.7 -11.0 

OFFIC03 -3.0 -1.0 -11.1 -3.5 -23.8 -7.5 

OFFIC08 -8.4 -2.7 -12.0 -3.8 -31.5 -10.0 

OFFIC16 -7.8 -2.5 0.4 0.1 -23.1 -7.3 

RETAIL1 -9.4 -3.0 -24.6 -7.8 -40.8 -13.0 

RSTRNT1 -12.7 -4.0 -37.1 -11.8 -79.7 -25.3 

The total annual reduction in energy use ranges widely across building designs, but the 

ASHRAE 90.1-2004, ASHRAE 90.1-2007, and LEC designs all decrease overall energy 

use across the state. Adopting ASHRAE 90.1-2004 results in annual reductions of 18.7 

GWh (63.7 GBtu) while adopting ASHRAE 90.1-2007 saves 32.8 GWh (112.0 GBtu) 

annually. The adoption of the LEC design as the state’s energy code would save energy 

for all building types and 67.2 GWh (229.5 GBtu) of total energy use annually for one 

year’s worth of new construction for these building types. 

22 A simple average for a state is used because no data for a weighted average is available regarding the
 

amount of new construction on a city-by-city basis.
 

23 State-level subcategory data are not available.
 

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Table 9-11 Statewide Change in Annual Energy Use for One Year of Construction, 

Colorado 

Building 

Type 

Subcat. 

Weight. m 2 

(1000s) 

ft2 

(1000s) 

Standard Edition 

2004 

kWh kBtu 

2007 

kWh kBtu 

LEC 

kWh kBtu 

APART04 

APART06 

44.9 % 

55.1 % 

183 

224 

1967 

2410 

-2 581 945 -8 815 869 

-3 204 843 -10 942 711 

-3 724 753 -12 717 908 

-4 358 644 -14 882 284 

-6 401 934 -21 858 955 

-7 860 201 -26 838 104 

HOTEL15 100.0 % 199 2147 -2 601 371 -8 882 201 -1 096 565 -3 744 144 -4 942 031 -16 874 218 

HIGHS02 100.0 % 331 3561 -996 825 -3 403 588 -3 663 683 -12 509 390 -7 870 278 -26 872 513 

OFFIC03 

OFFIC08 

OFFIC16 

37.4 % 

40.4 % 

22.2 % 

162 

174 

96 

1739 

1875 

1032 

-1 082 947 -3 697 645 

-1 465 291 -5 003 132 

-747 292 -2 551 575 

-2 169 553 -7 407 787 

-2 089 987 -7 136 114 

40 723 139 045 

-5 608 663 -19 150 389 

-5 491 202 -18 749 324 

-2 210 409 -7 547 288 

RETAIL1 100.0 % 579 6235 -5 465 300 -18 660 885 -14 251 754 -48 661 618 -23 662 413 -80 793 652 

RSTRNT1 100.0 % 40 428 -506 957 -1 730 969 -1 477 307 -5 044 160 -3 172 792 -10 833 277 

Total 1988 21 394 -18 652 769 -63 688 575 -32 791 523 -111 964 360 -67 219 923 -229 517 720 

Note: Dormitories are excluded because no such floor area category is reported in the construction data. 

Assuming that the buildings considered in this study, which represent 60.4 % of all new 

commercial floor space in the state, are generally representative of the entire new 

commercial building stock in the state, the results for the LEC design can be extrapolated 

to estimate the total statewide energy use savings to be 111.3 GWh (380.0 GBtu) 

annually. Annual savings of 111.3 GWh (380.0 GBtu) implies 1113 GWh (3800.0 GBtu) 

in energy savings over the 10-year study period. In comparison, ASHRAE 90.1-2004 and 

ASHRAE 90.1-2007 would save 30.9 GWh and 54.3 GWh annually, or 308.8 GWh and 

542.9 GWh over the 10-year study period, respectively. 

The statewide change in energy use varies across the 9 building types with reported floor 

area data within a building design. Building types that represent a greater amount of new 

floor area realize the largest total changes in energy use. The building types that have the 

greatest percentage reduction in energy use are not always the same buildings that lead to 

the greatest total reductions for the state. For example, the building types that lead to the 

greatest estimated reductions in energy use for the LEC design -- retail stores, high 

schools, and high-rise apartment buildings -- rank 3rd, 11th , and 6th in percentage 

reduction, respectively, among the 11 building types, as reported in Table 9-2. The two 

high-rise buildings with 100 % window glazing realize the smallest statewide reductions 

in energy use for ASHRAE 90.1-2004 and ASHRAE 90.1-2007 due to the consolidation of 

climate zones from ASHRAE 90.1-2001 to ASHRAE 90.1-2004, which relaxes the 

window U-factor requirements. ASHRAE 90.1-2007 results in a small increase in energy 

use for 16-story office buildings due to relaxation of the window SHGC requirements 

relative to ASHRAE 90.1-2004. 

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9.2.2 Energy Costs 

Table 9-12 reports the average per unit change in energy costs by building type and 

building design. Energy costs are calculated using the annual energy use, energy cost 

rates, and energy price escalation rates as defined in Section 3.2. 

Table 9-12 Average Per Unit Change in Energy Costs, 10-Year, Colorado 

Building Standard Edition 

Type 2004 

$/m2 $/ft2 

2007 

$/m2 $/ft2 

LEC 

$/m2 $/ft2 

APART04 -$15.02 -$1.40 -$16.75 -$1.56 -$27.18 -$2.53 

APART06 -$15.15 -$1.41 -$16.53 -$1.54 -$28.24 -$2.62 

DORMI04 -$12.36 -$1.15 -$13.75 -$1.28 -$22.76 -$2.11 

DORMI06 -$16.54 -$1.54 -$17.28 -$1.60 -$29.72 -$2.76 

HOTEL15 -$14.23 -$1.32 -$10.09 -$0.94 -$21.82 -$2.03 

HIGHS02 -$5.75 -$0.53 -$7.96 -$0.74 -$20.85 -$1.94 

OFFIC03 -$5.87 -$0.55 -$7.24 -$0.67 -$21.21 -$1.97 

OFFIC08 -$6.45 -$0.60 -$7.04 -$0.65 -$19.61 -$1.82 

OFFIC16 -$7.44 -$0.69 -$2.04 -$0.19 -$17.02 -$1.58 

RETAIL1 -$8.50 -$0.79 -$12.52 -$1.16 -$23.00 -$2.14 

RSTRNT1 -$12.57 -$1.17 -$18.75 -$1.74 -$45.76 -$4.25 

Table 9-13 reports the statewide changes in total energy costs by building type and 

building design, which account for one year’s worth of new construction evaluated over 

10 years of building operation. Overall, reductions in energy costs are greater for the 

more energy efficient building designs: $18.5 million, $21.1 million, and $43.9 million 

for adopting ASHRAE 90.1-2004, ASHRAE 90.1-2007, and LEC, respectively. All 

building types realize energy cost savings for all three of these building designs. 

Assuming that the buildings considered in this study are generally representative of the 

entire new commercial building stock in the state, the results for ASHRAE 90.1-2004, 

ASHRAE 90.1-2007, and LEC can be extrapolated to estimate the total statewide energy 

cost savings of $30.6 million, $35.0 million, and $72.7 million over the 10-year study 

period, respectively. 

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Colorado 

Table 9-13 Statewide Change in Energy Costs for One Year of Construction, 10­

Year, Colorado 

Building Subcategory m 2 ft2 Standard Edition 

Type Weighting (1000s) (1000s) 2004 2007 LEC 

APART04 44.9 % 183 1967 -$2 744 758 -$3 060 808 -$4 967 750 

APART06 55.1 % 224 2410 -$3 391 792 -$3 700 430 -$6 321 780 

HOTEL15 100.0 % 199 2147 -$2 839 304 -$2 012 375 -$4 352 321 

HIGHS02 100.0 % 331 2403 -$1 284 340 -$1 776 264 -$4 653 715 

OFFIC03 37.4 % 162 1739 -$948 189 -$1 169 098 -$3 426 305 

OFFIC08 40.4 % 174 1875 -$1 122 606 -$1 226 719 -$3 415 693 

OFFIC16 22.2 % 96 1032 -$712 783 -$195 861 -$1 630 928 

RETAIL1 100.0 % 579 6235 -$4 921 446 -$7 250 291 -$13 324 499 

RSTRNT1 100.0 % 40 428 -$500 117 -$746 212 -$1 821 095 

Total 1988 20 235 -$18 465 334 -$21 138 058 -$43 914 086 

Note: Dormitories are excluded because no such floor area category is reported in the construction 

d t 

9.2.3 Energy-related Carbon Emissions 

Table 9-14 reports the average reduction in energy-related carbon emissions over 10 

years, per m 

2 (ft2

), by building type and building design. The carbon emissions estimation 

approach is defined in Section 5.3. 

Table 9-14 Average Per Unit Change in Carbon Emissions, 10-Year, Colorado 

Building Standard Edition 

Type 2004 

kg/m2 lb/ft2 

2007 

kg/m2 lb/ft2 

LEC 

kg/m2 lb/ft2 

APART04 -239.5 -49.1 -263.1 -53.9 -425.3 -87.1 

APART06 -241.6 -49.5 -260.3 -53.3 -443.0 -90.7 

DORMI04 -198.3 -40.6 -216.0 -44.2 -354.7 -72.6 

DORMI06 -263.8 -54.0 -273.6 -56.0 -467.4 -95.7 

HOTEL15 -227.3 -46.6 -164.4 -33.7 -344.3 -70.5 

HIGHS02 -93.8 -19.2 -123.8 -25.4 -328.9 -67.4 

OFFIC03 -92.6 -19.0 -109.7 -22.5 -325.6 -66.7 

OFFIC08 -100.8 -20.6 -107.7 -22.1 -301.5 -61.7 

OFFIC16 -117.9 -24.2 -34.6 -7.1 -265.3 -54.3 

RETAIL1 -134.3 -27.5 -188.5 -38.6 -350.3 -71.7 

RSTRNT1 -199.6 -40.9 -282.2 -57.8 -698.1 -143.0 

Table 9-15 applies the Table 9-14 results to one year’s worth of new building 

construction in the state to estimate statewide reduction in carbon emissions from 

adoption of more energy efficient codes. The total reduction in carbon emissions ranges 

widely across building designs, but the ASHRAE 90.1-2004, ASHRAE 90.1-2007, and 

LEC designs all decrease carbon emissions. The adoption of ASHRAE 90.1-2004 results 

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Colorado 

in savings of 293 683 metric tons while adopting ASHRAE 90.1-2007 saves 327 025 

metric tons over a 10-year study period. The adoption of the LEC design as the state’s 

energy code decreases carbon emissions by 680 244 metric tons over the 10-year study 

period for one year’s worth of new commercial construction for these building types. 

Assuming that the buildings considered in this study are generally representative of the 

entire new building stock in the state, the results for ASHRAE 90.1-2004, ASHRAE 

90.1-2007, and LEC can be extrapolated to estimate statewide reductions in carbon 

emissions of 486 230 metric tons, 541 432 metric tons, and 1.1 million metric tons over 

the 10-year study period, respectively. 

Table 9-15 Statewide Change in Total Carbon Emissions for One Year of 

Construction, 10-Year, Colorado – Metric Tons 

Building Subcategory m 2 ft2 Standard Edition 

Type Weighting (1000s) (1000s) 2004 2007 LEC 

APART04 44.9 % 183 1967 -43 777 -48 088 -77 740
 

APART06 55.1 % 224 2410 -54 085 -58 262 -99 177
 

HOTEL15 100.0 % 199 2147 -45 345 -32 784 -68 685 

HIGHS02 100.0 % 331 2403 -20 947 -27 639 -73 418 

OFFIC03 37.4 % 162 1739 -14 958 -17 723 -52 588 

OFFIC08 40.4 % 174 1875 -17 552 -18 757 -52 512 

OFFIC16 22.2 % 96 1032 -11 302 -3318 -25 429 

RETAIL1 100.0 % 579 6235 -77 772 -109 222 -202 911 

RSTRNT1 100.0 % 40 428 -7945 -11 232 -27 785 

Total 1988 20 235 -293 683 -327 025 -680 244 

Note: Dormitories are excluded because no such floor area category is reported in 

the construction data. 

9.2.4 Life-Cycle Costs 

Table 9-16 reports the average change in life-cycle cost over 10 years, per m2 (ft2), by 

building type and building design. As discussed in Section 5.2, life-cycle costs include 

construction costs, maintenance, repair, and replacement costs, energy costs, and residual 

values. 

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Colorado 

Table 9-16 Average Per Unit Change in Life-Cycle Costs, 10-Year, Colorado
 

Building Standard Edition 

Type 2004 

$/m2 $/ft2 

2007 

$/m2 $/ft2 

LEC 

$/m2 $/ft2 

APART04 -$15.22 -$1.41 -$18.23 -$1.69 -$12.01 -$1.12 

APART06 -$15.11 -$1.40 -$17.33 -$1.61 -$11.56 -$1.07 

DORMI04 -$22.39 -$2.08 -$26.87 -$2.50 -$39.72 -$3.69 

DORMI06 -$19.81 -$1.84 -$20.91 -$1.94 -$18.12 -$1.68 

HOTEL15 -$20.06 -$1.86 -$15.60 -$1.45 -$10.73 -$1.00 

HIGHS02 -$6.15 -$0.57 -$8.93 -$0.83 -$15.15 -$1.41 

OFFIC03 -$18.67 -$1.73 -$20.70 -$1.92 -$44.11 -$4.10 

OFFIC08 -$19.31 -$1.79 -$21.44 -$1.99 -$42.52 -$3.95 

OFFIC16 -$7.59 -$0.70 -$2.43 -$0.23 $1.10 $0.10 

RETAIL1 -$13.66 -$1.27 -$18.25 -$1.70 -$12.78 -$1.19 

RSTRNT1 -$32.22 -$2.99 -$59.08 -$5.49 -$98.13 -$9.12 

Table 9-17 applies the Table 9-16 results to one year’s worth of new building 

construction in the state to estimate statewide changes in life-cycle costs from adoption of 

more energy-efficient codes. Total reductions in life-cycle costs over the 10-year study 

period vary across building designs. ASHRAE 90.1-2004 and ASHRAE 90.1-2007 result 

in a decrease in life-cycle costs for all 9 building types while the LEC design decreases 

life-cycle costs for 8 of 9 building types. The 16-story office building realizes the 

smallest total reductions in life-cycle costs for all three alternative building designs and, 

for the LEC design, realizes increases in life-cycle costs. ASHRAE 90.1-2007 results in 

greater total reductions in life-cycle costs than ASHRAE 90.1-2004 for the building types 

considered in this study ($32.5 million versus $27.8 million). The LEC design leads to 

the greatest total reductions in life-cycle costs of $36.0 million. 

Assuming that the buildings considered in this study are generally representative of the 

entire new commercial building stock in the state, the results for the ASHRAE 90.1-2004, 

ASHRAE 90.1-2007, and LEC designs can be extrapolated to estimate statewide changes 

in life-cycle costs of $46.1 million, $53.9 million, and $59.7 million over the 10-year 

study period, respectively. 

75
 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

data.

Colorado 

Table 9-17 Statewide Change in Life-Cycle Costs for One Year of Construction, 

10-Year, Colorado 

Building 

Type 

Subcategory 

Weighting 

m 2 

(1000s) 

ft2 

(1000s) 

Standard Edition 

2004 2007 LEC 

APART04 

APART06 

44.9 % 183 1967 -$2 780 914 -$3 331 475 -$2 195 187 

55.1 % 224 2410 -$3 381 651 -$3 878 490 -$2 586 926 

HOTEL15 100.0 % 199 2147 -$4 001 180 -$3 112 617 -$2 139 459 

HIGHS02 100.0 % 331 2403 -$1 373 361 -$1 992 603 -$3 382 270 

OFFIC03 

OFFIC08 

OFFIC16 

37.4 % 162 1739 -$3 015 796 -$3 342 811 -$7 123 855 

40.4 % 174 1875 -$3 363 646 -$3 733 863 -$7 405 617 

22.2 % 96 1032 -$727 029 -$232 930 $105 555 

RETAIL1 100.0 % 579 6235 -$7 915 065 -$10 570 652 -$7 401 280 

RSTRNT1 100.0 % 40 428 -$1 282 163 -$2 351 325 -$3 905 355 

Total 1988 20 235 -$27 840 805 -$32 546 766 -$36 034 394 

Note: Dormitories are excluded because no such floor area category is reported in the construction 

9.3 State Summary 

Colorado is one of the few states that has adopted ASHRAE 90.1-2001 as its state energy 

code for commercial buildings, and represents the Rocky Mountain region of the United 

States. On average, adopting a newer edition of ASHRAE 90.1 leads to reductions in 

energy use, energy costs, and cradle-to-grave energy-related carbon emissions. However, 

adopting ASHRAE 90.1-2007 increases energy use for some location-building type 

combinations, particularly for 16-story office buildings. ASHRAE 90.1-2004 condenses 

the 26 climate zones defined in ASHRAE 90.1-1999/2001 into 8 climate zones. As a 

result, some of the building envelope requirements (window U-factors and insulation Rvalues) are slightly less stringent for some locations. Additionally, ASHRAE 90.1-2007 

further relaxes the window SHGC requirements for some locations. 

Colorado is one of the few states that have at least one city that has adopted a more 

stringent energy standard edition than the state. Grand Junction has adopted ASHRAE 

90.1-2004, which tempers the reductions in energy use, energy costs, and energy-related 

carbon emissions from the adoption of either the ASHRAE 90.1-2007 or LEC designs. 

Despite these factors, the adoption of more efficient building design requirements leads 

to savings in energy use and life-cycle costs. Based on the average annual new 

construction in the state from 2003 to 2007 and a 10-year study period, adopting 

ASHRAE 90.1-2007 as the state’s energy code for commercial buildings would lead to 

energy use savings of 543 GWh, energy cost savings of $35.0 million, life-cycle cost 

savings of $53.9 million, and 541 432 metric tons of carbon emissions reductions for one 

year’s worth of commercial building construction. Adopting the LEC design would be 

even more beneficial for the state with savings of 1113 GWh (3800.0 GBtu), 

76
 
 

 

Colorado 

$72.7 million in energy costs, 1.1 million metric tons of carbon emissions, and life-cycle 

cost savings of $59.7 million. 

77
 
Colorado 

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Hawaii 

10 Hawaii 

Hawaii is one of two states in the West Census Region that have adopted ASHRAE 

90.1-2004 as their state energy code for commercial buildings, and is located in the 

Pacific Census Division and Climate Zone 1. Table 10-1 provides an overview of 

Hawaii’s simulated energy use keyed to building type and energy standard edition. 

Average energy use varies across building types and building designs. The 4-story 

dormitory uses the least amount of energy at 74 kWh/m2 to 95 kWh/m2 (24 kBtu/ ft2 to 

30 kBtu/ft2) annually. The restaurant uses the greatest amount of energy for the ASHRAE 

90.1-1999 design at 157 kWh/m2 (50 kBtu/ft2

) annually. The 6-story dormitory uses the 

greatest amount of energy for the LEC design at 106 kWh/m2 (34 kBtu/ft2) annually. 

Table 10-1 Average Annual Energy Use by Building Type and Standard Edition, 

Hawaii 

Building 

Type 

Standard Edition 

2004 2007 LEC 

kWh/m2 kBtu/ft2 kWh/m2 kBtu/ft2 kWh/m2 kBtu/ft2 

APART04 124 39 121 38 99 31 

APART06 124 39 121 38 99 31 

DORMI04 95 30 93 29 74 24 

DORMI06 138 44 135 43 106 34 

HOTEL15 96 30 98 31 78 25 

HIGHS02 115 37 114 36 84 27 

OFFIC03 119 38 118 37 86 27 

OFFIC08 111 35 109 35 87 28 

OFFIC16 114 36 118 37 95 30 

RETAIL1 121 38 120 38 94 30 

RSTRNT1 157 50 153 49 102 32 

The detailed analysis for this state reports the changes in energy use, energy costs, 

energy-related carbon emissions, and life-cycle costs from adoption of increasingly 

stringent energy codes. The results are reported in terms of average percentage savings on 

a statewide and city-by-city basis, and as total savings on a statewide basis. 

10.1 Percentage Savings 

Changes in percentage terms allow for direct comparisons across building type and 

location within a state. This section discusses the average percentage changes from 

investing in more energy efficient designs in the state of Hawaii. 

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Hawaii 

10.1.1 Energy Use 

Table 10-2 shows a large variation in the percentage change in energy use for ASHRAE 

90.1-2007 relative to ASHRAE 90.1-2004, ranging from 3.1 % to -2.9 % with an average 

of -1.1 %. For the high-rise, 100 % glazed buildings (16-story office building and 

15-story hotel), ASHRAE 90.1-2007 is actually less energy efficient than ASHRAE 

90.1-2004 because the maximum window SHGC requirement in Zone 1 for buildings 

with fenestration accounting for greater than 40 % of wall surface area is less stringent 

for ASHRAE 90.1-2007 relative to ASHRAE 90.1-2004. Buildings in warmer climate 

zones benefit from decreasing external heat gains through fenestration. The resulting 

higher heat gain through fenestration increases cooling load requirements. The 100 % 

glazing amplifies the energy loss enough to overwhelm the energy efficiency gains 

obtained from other measures, such as increased insulation R-value. 

Table 10-2 Average Percentage Change in Energy Use from Adoption of Newer 

Standard Editions, Hawaii 

Building Standard Edition
 

Type
 2007 LEC 

APART04 -2.7 -20.4 

APART06 -2.5 -20.7 

DORMI04 -2.9 -22.1 

DORMI06 -2.3 -23.0 

HOTEL15 2.1 -18.0 

HIGHS02 -1.0 -26.7 

OFFIC03 -1.6 -28.0 

OFFIC08 -1.4 -21.3 

OFFIC16 3.1 -16.4 

RETAIL1 -0.5 -22.3 

RSTRNT1 -2.6 -34.8 

Average -1.1 -23.1 

The LEC design realizes percentage decreases in energy use relative to ASHRAE 

90.1-2004, ranging from -16.4 % to -34.8 % with an average of -23.1 %. Similar to the 

ASHRAE 90.1-2007 design, the smallest reductions in energy use for the LEC design 

occurs in the 16-story office building and hotel. 

10.1.2 Energy Costs 

Table 10-3 shows significant variation in the percentage changes in average energy costs 

for ASHRAE 90.1-2007 relative to ASHRAE 90.1-2004, ranging from 3.1 % to -2.9 % 

depending on the building type, with an average of -1.1 %. As with energy use savings, 

adopting ASHRAE 90.1-2007 results in an increase in energy costs relative to ASHRAE 

90.1-2004 for the two high-rise buildings. The LEC design realizes greater reductions in 

energy costs than the ASHRAE 90.1-2007 design, with the average percentage change by 

80
 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Hawaii 

building type ranging from -16.4 % to -34.8 % with an overall average of -23.1 % for 10 

years of building operation. The percentage reductions in energy costs are nearly 

identical to the reductions in energy use for all building types because electricity 

consumption accounts for nearly 100 % of total energy use. 

Table 10-3 Average Percentage Change in Energy Costs, 10-Year, Hawaii 

Building Standard Edition 

Type 2007 LEC 

APART04 -2.7 -20.4 

APART06 -2.5 -20.7 

DORMI04 -2.9 -22.1 

DORMI06 -2.3 -23.0 

HOTEL15 2.1 -18.1 

HIGHS02 -1.0 -26.7 

OFFIC03 -1.6 -28.0 

OFFIC08 -1.4 -21.3 

OFFIC16 3.1 -16.4 

RETAIL1 -0.5 -22.3 

RSTRNT1 -2.6 -34.8 

Average -1.1 -23.1 

10.1.3 Energy-related Carbon Emissions Reduction 

Table 10-4 shows significant variation in the average percentage change in energy-related 

carbon emissions for the ASHRAE 90.1-2007 design across building types, ranging from 

3.1 % to -2.9 % with an average of -1.1 %. The LEC design leads to significant changes 

in average carbon emissions, ranging from -16.4 % to -34.8 % depending on the building 

type with an average of -23.1 % across all building types. As would be expected, a more 

energy efficient building design results in greater reductions in carbon emissions. The 

percentage reductions in carbon emissions are nearly identical to the reductions in energy 

use for all building types because electricity consumption accounts for nearly 100 % of 

total energy use and, therefore, driving any changes in carbon emissions. 

81
 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Hawaii 

Table 10-4 Average Percentage Change in Energy-related Carbon Emissions, 10­

Year, Hawaii 

Building Standard Edition 

Type 2007 LEC 

APART04 -2.7 -20.4 

APART06 -2.5 -20.7 

DORMI04 -2.9 -22.1 

DORMI06 -2.3 -23.0 

HOTEL15 2.2 -18.1 

HIGHS02 -1.0 -26.7 

OFFIC03 -1.6 -28.0 

OFFIC08 -1.4 -21.3 

OFFIC16 3.1 -16.4 

RETAIL1 -0.5 -22.3 

RSTRNT1 -2.6 -34.8 

Average -1.1 -23.1 

10.1.4 Life-Cycle Costs 

The most cost-effective building design for each building type is bolded in Table 10-5. 

The LEC design is the most life-cycle cost-effective building design for all building 

types. Since the percentage changes in life-cycle costs resulting from the adoption of the 

LEC design range from -6.3 % to -0.6 %, the LEC design is cost effective for the state to 

adopt as its state energy code for commercial buildings. For 9 of 11 building types, 

ASHRAE 90.1-2007 leads to percentage reductions in life-cycle costs relative to ASHRAE 

90.1-2004. The 16-story office building and hotel are the only buildings that realize 

increases in life-cycle costs. Given that nine building types realize a percentage decrease 

in life-cycle costs, it is likely that adopting ASHRAE 90.1-2007 will decrease total lifecycle costs. 

Table 10-5 Average Percentage Change in Life-Cycle Costs, 10-Year, Hawaii 

Building Standard Edition 

Type 2007 LEC 

APART04 -0.5 -1.7 

APART06 -0.4 -1.6 

DORMI04 -0.8 -3.6 

DORMI06 -0.4 -2.5 

HOTEL15 0.3 -0.6 

HIGHS02 -0.1 -4.2 

OFFIC03 -0.3 -5.7 

OFFIC08 -0.3 -3.6 

OFFIC16 0.6 -0.6 

RETAIL1 -0.0 -3.1 

RSTRNT1 -0.6 -6.3 

Average -0.2 -3.1 

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Hawaii 

10.1.5 City Comparisons 

Simulations are run for two cities located in Hawaii, both of which are located in Zone 1: 

Hilo and Honolulu. While the two cities are located in the same climate zone, the results 

may still vary for two reasons. First, cities within the same climate zone may have some 

variation in the local climate, which can lead to variation in energy consumption. Second, 

construction material and labor costs may vary significantly by locality. 

As can be seen in Table 10-6, the average reduction in energy use for all building types 

from adopting newer energy standard editions does not vary significantly across cities. 

For the ASHRAE 90.1-2007 design, the percentage change in average energy use ranges 

minimally from -1.1 % to -1.2 %. For the LEC design, the percentage change in average 

energy use ranges from -22.9 % to -23.2 %. There is not a significant impact from the 

variation in weather across cities in Hawaii. 

Table 10-6 Average Percentage Change in Energy Use from Adoption of Newer 

Standard Editions by City, Hawaii 

Cities Zone Standard Edition 

2007 LEC 

Hilo 1 -1.2 -22.9 

Honolulu 1 -1.1 -23.2 

Average -1.1 -23.1 

The variations in energy costs across cities are a result of two factors, the reduction in 

energy use and the fuel source of the reduction. Table 10-7 shows that the average 

reduction in energy costs for all building types varies marginally between cities. For the 

ASHRAE 90.1-2007 design, the percentage change in average energy costs ranges 

from -1.1 % to -1.2 %. For the LEC design, the percentage change in average energy 

costs ranges from -22.9 % to -23.2 %. 

Table 10-7 Average Percentage Change in Energy Costs by City, 10-Year, Hawaii 

Cities Zone Standard Edition 

2007 LEC 

Hilo 1 -1.2 -22.9 

Honolulu 1 -1.1 -23.2 

Average -1.1 -23.1 

Table 10-8 reports energy-related carbon emissions by city for the state. For both cities, 

the more energy efficient designs result in greater reductions in carbon emissions. The 

average percentage change in carbon emissions varies minimally between cities. 

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Hawaii 

Table 10-8 Average Percentage Change in Carbon Emissions by City, Hawaii
 

Cities Zone Standard Edition 

2007 LEC 

Hilo 1 -1.2 -23.7 

Honolulu 1 -1.1 -24.0 

Average -1.2 -23.9 

The data reported in Table 10-9 show that adoption of the ASHRAE 90.1-2007 design 

decreases life-cycle costs for both cities, with no variation in the change in life-cycle 

costs (-0.1 %). The LEC design realizes the greatest reduction in life-cycle costs between 

cities in the state with minimal variation (-4.1 % to -4.2 %). 

Table 10-9 Average Percentage Change in Life-Cycle Costs by City, 10-Year, 

Hawaii 

Cities Zone Standard Edition 

2007 LEC 

Hilo 1 -0.1 -4.1 

Honolulu 1 -0.1 -4.2 

Average -0.1 -4.1 

10.2 Total Savings 

How much can Hawaii save, in terms of energy use, energy costs, and carbon emissions, 

from adopting a more stringent state energy code for commercial buildings? What are the 

life-cycle costs associated with the new energy code adoption? To answer these 

questions, it is necessary to estimate savings per unit of floor area for each building type 

in the state. 

10.2.1 Energy Use 

Table 10-10 reports the average per unit change in annual energy use by building type 

and building design in the state.24 The reduction per m2 (ft2) is multiplied by the 

estimated m2 (ft2

) of new construction of each building type, and Table 10-11 reports the 

estimated average annual floor area of new construction and the total annual reduction in 

energy use for each building type. The weightings within a category (e.g., small, medium, 

and large office buildings) are based on the national average percentage of new building 

construction for the category that is represented by each subcategory.25 

24 A simple average for a state is used because no data for a weighted average is available regarding the
 

amount of new construction on a city-by-city basis.
 

25 State-level subcategory data are not available.
 

84
 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Hawaii 

Table 10-10 Average Per Unit Change in Annual Energy Use, Hawaii
 

Building Standard Edition 

Type 2007 

kWh/m2 kBtu/ft2 

LEC 

kWh/m2 kBtu/ft2 

APART04 

APART06 

-3.4 -1.1 

-3.1 -1.0 

-25.3 -8.0 

-25.8 -8.2 

DORMI04 

DORMI06 

-2.7 -0.9 

-3.2 -1.0 

-21.0 -6.7 

-31.7 -10.1 

HOTEL15 2.1 0.7 -17.3 -5.5 

HIGHS02 -1.9 -0.6 -33.5 -10.6 

OFFIC03 

OFFIC08 

OFFIC16 

-1.2 -0.4 

-1.6 -0.5 

3.5 1.1 

-30.8 -9.8 

-23.6 -7.5 

-18.7 -5.9 

RETAIL1 -0.6 -0.2 -27.0 -8.6 

RSTRNT1 -4.1 -1.3 -54.8 -17.4 

The annual reduction in energy use shown in Table 10-11 ranges widely across building 

designs, but the ASHRAE 90.1-2007 and LEC designs both decrease total statewide 

energy use. The adoption of the ASHRAE 90.1-2007 design results in reductions of 863.0 

MWh (2.9 GBtu) annually. ASHRAE 90.1-2007 increases total energy use for the two 

high-rise buildings and decreases total energy use for the other seven building types with 

the 6- and 4-story apartment buildings realizing the greatest reductions. The adoption of 

the LEC design as the state’s energy code for commercial buildings would save 9.9 GWh 

(33.7 GBtu) of total statewide energy use annually for one year’s worth of new 

construction for these building types. 

Table 10-11 Statewide Change in Annual Energy Use for One Year of Construction, 

Hawaii 

Building Subcategory m 2 ft2 Standard Edition 

Type Weighting (1000s) (1000s) 2007 LEC 

kWh kBtu kWh kBtu 

APART04 44.9 % 115 1238 -385 506 -1 316 282 -2 906 299 -9 923 355
 

APART06 55.1 % 141 1516 -432 225 -1 475 801 -3 628 358 -12 388 776
 

HOTEL15 100.0 % 18 198 37 835 129 185 -317 386 -1 083 693 

HIGHS02 100.0 % 18 197 -21 597 -73 740 -563 322 -1 923 424 

OFFIC03 37.4 % 13 138 -24 301 -82 973 -428 551 -1 463 257 

OFFIC08 40.4 % 14 148 -21 940 -74 913 -325 800 -1 112 422 

OFFIC16 22.2 % 8 82 26 537 90 608 -142 047 -485 008 

RETAIL1 100.0 % 55 588 -34 571 -118 041 -1 474 736 -5 035 383 

RSTRNT1 100.0 % 2 19 -7278 -24 852 -96 687 -330 132 

Total 383 4124 -863 045 -2 946 808 -9 883 187 -33 745 449 

Note: Dormitories are excluded because no such floor area category is reported in the construction data. 

85
 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Hawaii 

Assuming that the buildings considered in this study, which represent 71.4 % of all new 

commercial floor space in the state, are generally representative of the entire new 

commercial building stock in the state, the results can be extrapolated to estimate the 

statewide savings to be 1.2 GWh (4.1 GBtu) and 13.8 GWh (47.3 GBtu) per year for 

adoption of the ASHRAE 90.1-2007 and LEC designs, respectively. These savings imply 

12.1 GWh (41.3 GBtu) and 138.4 GWh (472.6 GBtu) in energy use savings over the 

10-year study period. 

The relative reduction in energy use across building types in Table 10-11 is consistent 

across building designs. The greatest total reductions are realized by 6- and 4-story 

apartment buildings because they represent 36.8 % and 30.0 %, respectively, of the 

combined new construction in the state for the building types in this study while all other 

building types represent less than 14.3 %. The amount of new construction overwhelms 

the relative percentage changes in energy use. The building types that lead to the greatest 

estimated reductions in energy use for the LEC design – 4- and 6-story apartment 

buildings -- rank 8th and 9th in percentage reduction, respectively, among the 11 building 

types, as reported in Table 10-2. 

10.2.2 Energy Costs 

Table 10-12 reports the average per unit change in energy costs by building type and 

building design. Energy costs are calculated using the annual energy use, state average 

energy cost rates, and regional energy price escalation rates as defined in Section 3.2. 

Table 10-12 Average Per Unit Change in Energy Costs, 10-Year, Hawaii 

Building Standard Edition 

Type 2007 

$/m2 $/ft2 

LEC 

$/m2 $/ft2 

APART04 

APART06 

-$5.80 -$0.54 

-$5.30 -$0.49 

-$43.69 -$4.06 

-$44.53 -$4.14 

DORMI04 

DORMI06 

-$4.75 -$0.44 

-$5.53 -$0.51 

-$36.37 -$3.38 

-$54.86 -$5.10 

HOTEL15 $3.56 $0.33 -$29.87 -$2.78 

HIGHS02 -$3.29 -$0.31 -$57.97 -$5.39 

OFFIC03 

OFFIC08 

OFFIC16 

-$2.04 -$0.19 

-$2.75 -$0.26 

$6.05 $0.56 

-$53.23 -$4.94 

-$40.87 -$3.80 

-$32.39 -$3.01 

RETAIL1 -$1.09 -$0.10 -$46.70 -$4.34 

RSTRNT1 -$7.13 -$0.66 -$94.71 -$8.80 

Table 10-13 reports the statewide changes in total energy costs by building type and 

building design, which account for one year’s worth of new construction evaluated over 

10 years of building operation. Overall, reductions in energy costs are greater for the 

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Hawaii 

more energy efficient building designs: $1.5 million and $17.1 million for adopting the 

ASHRAE 90.1-2007 and LEC design, respectively. The increase in energy use for the 

high-rise buildings leads to an increase in energy costs for those buildings for ASHRAE 

90.1-2007. All building types realize energy cost savings for the LEC design. The energy 

cost savings are highly correlated with the energy use savings. Assuming that the 

buildings considered in this study, which represent 71.4 % of all new commercial floor 

space in the state, are generally representative of the entire new commercial building 

stock in the state, the results for the ASHRAE 90.1-2007 and LEC design can be 

extrapolated to estimate the total statewide energy cost savings of $2.1 million and $23.9 

million over the 10-year study period, respectively. 

Table 10-13 Statewide Change in Energy Costs for One Year of Construction, 

10-Year, Hawaii 

Building Subcategory m 2 ft2 Standard Edition 

Type Weighting (1000s) (1000s) 2007 LEC 

APART04 44.9 % 115 1238 -$666 591 -$5 025 381 

APART06 55.1 % 141 1516 -$747 375 -$6 273 919 

HOTEL15 100.0 % 18 198 $65 458 -$548 923 

HIGHS02 100.0 % 18 197 -$37 361 -$974 138 

OFFIC03 37.4 % 13 138 -$42 019 -$741 022 

OFFIC08 40.4 % 14 148 -$37 937 -$563 352 

OFFIC16 22.2 % 8 82 $45 910 -$245 644 

RETAIL1 100.0 % 55 588 -$59 778 -$2 550 016 

RSTRNT1 100.0 % 2 19 -$12 585 -$167 185 

Total 383 4124 -$1 492 279 -$17 089 580 

Note: Dormitories are excluded because no such floor area category is reported in 

10.2.3 Energy-related Carbon Emissions 

Table 10-14 reports the average reduction in energy-related carbon emissions over 10 

years, per m 

2 (ft2

), by building type and building design. The carbon emissions estimation 

approach is defined in Section 5.3. 

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Hawaii 

Table 10-14 Average Per Unit Change in Carbon Emissions, 10-Year, Hawaii
 

Building Standard Edition 

Type 2007 

kg/m2 lb/ft2 

LEC 

kg/m2 lb/ft2 

APART04 

APART06 

-28.0 -5.7 

-25.6 -5.3 

-211.2 -43.2 

-215.2 -44.1 

DORMI04 

DORMI06 

-23.0 -4.7 

-26.7 -5.5 

-175.8 -36.0 

-265.1 -54.3 

HOTEL15 17.2 3.5 -144.4 -29.6 

HIGHS02 -9.9 -2.0 -257.3 -52.7 

OFFIC03 

OFFIC08 

OFFIC16 

-15.9 -3.3 

-13.3 -2.7 

29.3 6.0 

-280.2 -57.4 

-197.5 -40.5 

-156.5 -32.1 

RETAIL1 -5.3 -1.1 -225.7 -46.2 

RSTRNT1 -34.5 -7.1 -457.8 -93.8 

Table 10-15 applies the Table 10-14 results to one year’s worth of new building 

construction in the state to estimate the statewide reduction in carbon emissions from 

adoption of more energy efficient codes. The total reduction in carbon emissions ranges 

widely across building designs, but the ASHRAE 90.1-2007 and LEC designs decrease 

carbon emissions for the state as a whole. The adoption of ASHRAE 90.1-2007 saves 

7212 metric tons over a 10-year study period. The adoption of the LEC design decreases 

carbon emissions by 82 598 metric tons over the 10-year study period for one year’s 

worth of new commercial construction for these building types. Assuming that the 

buildings considered in this study are generally representative of the entire new 

commercial building stock in the state, the results for the ASHRAE 90.1-2007 and LEC 

designs can be extrapolated to estimate the statewide reduction in carbon emissions of 

10 813 metric tons and 123 836 metric tons over the 10-year study period, respectively. 

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Hawaii 

Table 10-15 Statewide Change in Total Carbon Emissions for One Year of 

Construction, 10-Year, Hawaii – Metric Tons 

Building Subcategory m 2 ft2 Standard Edition
 

Type Weighting (1000s) (1000s) 2007 LEC
 

APART04 44.9 % 115 1238 -3222 -24 289
 

APART06 55.1 % 141 1516 -3612 -30 323
 

HOTEL15 100.0 % 18 198 316 -2653 

HIGHS02 100.0 % 18 197 -181 -4708 

OFFIC03 37.4 % 13 138 -203 -3582 

OFFIC08 40.4 % 14 148 -183 -2723 

OFFIC16 22.2 % 8 82 222 -1187 

RETAIL1 100.0 % 55 588 -289 -12 325 

RSTRNT1 100.0 % 2 19 -61 -808 

Total 383 4124 -7212 -82 598 

Note: Dormitories are excluded because no such floor area category is 

reported in the construction data. 

10.2.4 Life-Cycle Costs 

Table 10-16 reports the average change in life-cycle cost over 10 years, per m2 (ft2

), by 

building type and building design. As discussed in Section 5.2, life-cycle costs include 

construction costs, maintenance, repair, and replacement costs, energy costs, and residual 

values. 

Table 10-16 Average Per Unit Change in Life-Cycle Costs, 10-Year, Hawaii 

Building Standard Edition 

Type 2007 

$/m2 $/ft2 

LEC 

$/m2 $/ft2 

APART04 

APART06 

-$5.99 -$0.56 

-$4.96 -$0.46 

-$21.92 -$2.04 

-$21.75 -$2.02 

DORMI04 

DORMI06 

-$10.52 -$0.98 

-$5.16 -$0.48 

-$46.53 -$4.32 

-$35.23 -$3.27 

HOTEL15 

HIGHS02 

$4.27 $0.40 

-$1.18 -$0.11 

-$6.99 -$0.65 

-$46.61 -$4.33 

OFFIC03 

OFFIC08 

OFFIC16 

-$3.35 -$0.31 

-$3.31 -$0.31 

$6.67 $0.62 

-$66.42 -$6.17 

-$42.72 -$3.97 

-$6.61 -$0.61 

RETAIL1 

RSTRNT1 

-$0.23 -$0.02 

-$11.20 -$1.04 

-$30.57 -$2.84 

-$117.17 -$10.89 

Table 10-17 applies the Table 10-16 results to one year’s worth of new building 

construction in the state to estimate the change in statewide life-cycle costs from adoption 

of more energy-efficient codes. ASHRAE 90.1-2007 results in total reductions in 

life-cycle costs of $1.4 million over the 10-year study period relative to ASHRAE 

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Hawaii 

90.1-2004 for the building types considered in this study. The LEC design leads to a 

decrease in total statewide life-cycle costs of $9.9 million, while reducing life-cycle costs 

for all 9 building types. The ASHRAE 90.1-2007 design both lead to an increase in 

life-cycle costs for hotels and 16-story office buildings. Assuming that the buildings 

considered in this study are generally representative of the entire new commercial 

building stock in the state, the results for ASHRAE 90.1-2007 and LEC design can be 

extrapolated to estimate the total reductions in life-cycle costs of $2.0 million and 

$13.9 million over the 10-year study period, respectively. 

Table 10-17 Statewide Change in Life-Cycle Costs for One Year of Construction, 

10-Year, Hawaii 

Building Subcategory m 2 ft2 Standard Edition
 

Type Weighting (1000s) (1000s) 2007 LEC
 

APART04 44.9 % 115 1238 -$688 775 -$2 521 478 

APART06 55.1 % 141 1516 -$698 930 -$3 064 132 

HOTEL15 100.0 % 18 198 $78 376 -$128 502 

HIGHS02 100.0 % 18 197 -$21 521 -$853 066 

OFFIC03 37.4 % 13 138 -$42 769 -$848 972 

OFFIC08 40.4 % 14 148 -$45 659 -$588 859 

OFFIC16 22.2 % 8 82 $50 621 -$50 100 

RETAIL1 100.0 % 55 588 -$12 661 -$1 669 534 

RSTRNT1 100.0 % 2 19 -$19 766 -$206 818 

Total 383 4124 -$1 401 083 -$9 931 461 

Note: Dormitories are excluded because no such floor area category is reported in the 

construction data. 

10.3 State Summary 

Hawaii is one of two states in the West Census Region that have adopted ASHRAE 

90.1-2004 as their current state energy code for commercial buildings. On average, 

adopting the ASHRAE 90.1-2007 design reduces energy use, energy costs, and 

energy-related carbon emissions, and does so in a cost-effective manner. Based on the 

average annual new construction in the state from 2003 to 2007 and a 10-year study 

period, adopting ASHRAE 90.1-2007 as the state’s energy code would lead to energy use 

savings of 12.1 GWh (41.3 GBtu), energy cost savings of $2.1 million, carbon emissions 

reductions of 10 813 metric tons, and life-cycle cost savings of $2.0 million. The LEC 

design would be lead to even greater impacts for the state with savings of 138.4 GWh 

(472.6 GBtu), energy cost savings of $23.9 million, carbon emissions reductions of 

123 836 metric tons for one year’s worth of commercial building construction while 

decreasing life-cycle costs by $13.9 million. 

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Idaho 

11 Idaho 

Idaho has adopted ASHRAE 90.1-2007 as its state energy code for commercial buildings, 

is located in the Mountain Census Division, and spans two climate zones (Zone 5B and 

Zone 6B). Table 11-1 provides an overview of Idaho’s simulated energy use keyed to 

building types and energy codes. Average energy use varies across building types and 

building designs. The 8-story office building uses the least amount of energy at 

79 kWh/m2 to 98 kWh/m2 (25 kBtu/ft2 to 31 kBtu/ft2

) annually. The high school uses the 

greatest amount of energy at 206 kWh/m2 to 220 kWh/m2 (65 kBtu/ft2 to 70 kBtu/ft2) 

annually. 

Table 11-1 Average Annual Energy Use by Building Type and Standard Edition, 

Idaho 

Building 

Type 

Standard Edition 

2007 

kWh/m2 kBtu/ft2 

LEC 

kWh/m2 kBtu/ft2 

APART04 145 46 130 41 

APART06 143 45 127 40 

DORMI04 113 36 99 31 

DORMI06 159 50 142 45 

HOTEL15 155 49 136 43 

HIGHS02 220 70 206 65 

OFFIC03 106 34 85 27 

OFFIC08 98 31 79 25 

OFFIC16 149 47 126 40 

RETAIL1 117 37 100 32 

RSTRNT1 160 51 118 37 

The detailed analysis for this state reports the changes in energy use, energy costs, 

energy-related carbon emissions, and life-cycle costs from adoption of the LEC design. 

The results are reported in terms of average percentage savings on a statewide and 

city-by-city basis and as total savings on a statewide basis. 

11.1 Percentage Savings 

Changes in percentage terms allow for direct comparisons across building types and 

locations within a state. This section discusses the average percentage changes from 

investing in the LEC design in the state of Idaho. 

11.1.1 Statewide Building Comparison 

Table 11-2 shows the percentage change in energy use, energy costs, energy-related 

carbon emissions, and life-cycle costs for the LEC design relative to ASHRAE 90.1-2007. 

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Idaho 

There is significant variation in the change in energy use for the LEC design relative to 

ASHRAE 90.1-2007, ranging from -6.0 % to -26.0 % depending on the building type with 

an overall average of -14.3 %. High schools realize the lowest reduction in energy use 

while restaurants realize the greatest reduction in energy use. 

Table 11-2 Average Percentage Change from Adoption of Newer Standard 

Editions, 10-Year, Idaho 

Building LEC 

Type Energy Use Energy Cost Carbon LCC 

APART04 -10.2 -14.8 -14.9 0.8 

APART06 -11.1 -16.5 -16.5 0.8 

DORMI04 -12.7 -16.4 -16.5 -1.2 

DORMI06 -10.6 -15.6 -15.7 0.5 

HOTEL15 -12.3 -15.9 -15.9 0.7 

HIGHS02 -6.0 -11.8 -11.9 -0.2 

OFFIC03 -19.7 -22.0 -22.1 -2.7 

OFFIC08 -19.3 -20.4 -20.4 -2.4 

OFFIC16 -15.3 -17.7 -17.8 0.9 

RETAIL1 -14.2 -16.3 -16.3 1.2 

RSTRNT1 -26.0 -30.8 -30.9 -2.7 

Average -14.3 -18.0 -18.1 -0.4 

There is a significant variation in the average percentage change in energy costs for the 

LEC design relative to ASHRAE 90.1-2007, ranging from -11.8 % to -30.8% depending 

on the building type with an average of -18.0 % for 10 years of building operation. The 

energy costs are reduced by a greater percentage than energy use because the energy 

efficiency measures decrease electricity consumption by a greater percentage than natural 

gas consumption. For 5 of the 11 building types, the energy efficiency measures increase 

natural gas consumption while decreasing electricity consumption. The shift is most 

prevalent for the high school, where the increase in natural gas consumption offsets 

41.8 % of the reduction in electricity consumption, and results in a percentage reduction 

in energy costs that is nearly twice the percentage reduction in energy use. The LEC 

design incorporates daylighting into the building design for all climate zones and 

overhangs for cities in Zone 5, which decreases the building’s internal and external heat 

gains, respectively. The shift in energy use from electricity to natural gas consumption to 

meet the greater heating loads decreases energy costs because natural gas is cheaper on a 

per unit of energy basis relative to electricity. 

There is significant variation in the average change in energy-related carbon emissions 

across building types for the LEC design relative to ASHRAE 90.1-2007, ranging 

from -11.9 % to -30.9 % with an average of -18.1 %. For the LEC design, the percentage 

reduction in carbon emissions is greater than the percentage reduction in energy use for 

all 11 building types because the energy efficiency measures decrease electricity 

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Idaho 

consumption by a greater percentage than natural gas consumption. The greater relative 

reduction in electricity leads to a greater reduction in carbon emissions because natural 

gas has a lower average carbon emissions rate than electricity. As mentioned above, the 

energy efficiency measures decrease electricity consumption while increasing natural gas 

consumption for 5 of the 11 building types. The combination of the reduction in total 

energy use and the shift in energy use from electricity consumption to natural gas 

consumption leads to even greater reductions in carbon emissions. 

The percentage change in life-cycle costs varies across building types, ranging 

from -2.7 % to 1.2 % for a 10-year study period. Five of the 11 building types realize 

reductions in life-cycle costs. Based on the overall average percentage change of -0.4 % 

in life-cycle costs, the LEC design may be cost-effective if the state adopted it as its state 

energy code for commercial buildings. 

11.1.2 City Comparisons 

Simulations are run for three cities located in Idaho: Boise and Lewiston in Zone 5B and 

Pocatello in Zone 6B. The results vary across cities within Idaho for several reasons. 

First, the state is covered by two climate zones. The ASHRAE 90.1 building design 

requirements vary across climate zones and may impact the relative energy efficiency of 

the building. Second, cities within the same climate zone still have some variation in the 

local climate, which can lead to variation in energy consumption. Third, construction 

material and labor costs vary by locality. 

Table 11-3 shows the percentage change in energy use, energy costs, energy-related 

carbon emissions, and life-cycle costs for the LEC design relative to ASHRAE 90.1-2007 

for each city in the state. The average percentage change in energy use for all building 

types from adopting the LEC design varies minimally across cities, ranging from -13.7 % 

to -14.7 %. Cities in Zone 5B realize slightly greater reductions than the city in Zone 6B. 

Table 11-3 Average Percentage Change from Adoption of Newer Standard Editions 

by City, 10-Year, Idaho 

Cities Zone LEC 

Energy Use Energy Cost Carbon LCC 

Boise 5B -14.7 -19.1 -19.2 -0.4 

Lewiston 5B -14.6 -18.7 -18.8 -0.8 

Pocatello 6B -13.7 -16.4 -16.5 0.1 

Average -14.3 -18.0 -18.2 -0.4 

The average percentage change in energy costs for all building types also varies slightly 

across cities, ranging from -16.4 % to -19.1 % for 10 years of operation. For all cities, 

reductions in energy costs are greater than reductions in energy use because the 

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Idaho 

percentage reduction in electricity consumption is greater than the reduction in natural 

gas consumption. Repeating the pattern, the average percentage change in carbon 

emissions for all building types also varies slightly across cities, ranging from -16.5 % 

to -19.2 %. Percentage changes in life-cycle costs for all building types vary across cities, 

ranging from 0.1 % to -0.8 %, with the city in Zone 6B (Pocatello) realizing an increase 

and the cities in Zone 5B (Boise and Lewiston) realizing a decrease in life-cycle costs. 

11.2 Total Savings 

How much can Idaho save, in terms of energy use, energy costs, and carbon emissions, 

from adopting a more stringent state energy code for commercial buildings? What are the 

life-cycle costs associated with the new energy code adoption? To answer these 

questions, it is necessary to estimate savings per unit of floor area for each building type 

in the state. 

11.2.1 Energy Use 

Table 11-4 reports the average per unit change in annual energy use by building type and 

building design in the state.26 The reduction per m2 (ft2

) is multiplied by the estimated m2 

(ft2) of new construction of each building type, and Table 11-5 reports the estimated 

average annual floor area of new construction and the total annual reduction in energy 

use for each building type. The weightings within a category (e.g., small, medium, and 

large office buildings) are based on the national average percentage of new building 

construction for the category that is represented by each subcategory.27 

Table 11-4 Average Per Unit Change in Annual Energy Use, Idaho 

Building Standard Edition 

Type LEC 

kWh/m2 kBtu/ft2 

APART04 -14.7 -4.7 

APART06 -15.8 -5.0 

DORMI04 -14.4 -4.6 

DORMI06 -16.7 -5.3 

HOTEL15 -19.0 -6.0 

HIGHS02 -20.9 -6.6 

OFFIC03 -13.3 -4.2 

OFFIC08 -18.9 -6.0 

OFFIC16 -22.7 -7.2 

RETAIL1 -16.8 -5.3 

RSTRNT1 -41.5 -13.2 

26 A simple average for a state is used because no data for a weighted average is available regarding the
 

amount of new construction on a city-by-city basis.
 

27 State-level subcategory data are not available.
 

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Idaho 

The adoption of the LEC design as the state’s energy code for commercial buildings 

would save energy for all building types and 8.9 GWh (30.4 GBtu) of total energy use 

annually for one year’s worth of new construction for these building types. Assuming that 

the buildings considered in this study, which represent 63.6 % of all new commercial 

floor space in the state, are generally representative of the entire new commercial 

building stock in the state, the results can be extrapolated to estimate statewide savings to 

be 14.0 GWh (47.8 GBtu) per year. These savings imply 139.9 GWh (477.7 GBtu) in 

energy use savings over the 10-year study period. 

The change in energy use varies across building types. The building types that have the 

greatest percentage reductions are not always the same buildings that lead to the greatest 

total reductions for the state. Instead the building types that represent a greater amount of 

new floor area realize the largest changes in energy use. The greatest total reductions are 

realized by retail stores and high schools because they represent 27.4 % and 24.9 %, 

respectively, of the combined new construction in the state for the building types in this 

study while all other building types represent 11.3 % or less. The amount of new 

construction overwhelms the relative percentage changes in energy use. The building 

types that lead to the greatest estimated reductions in energy use for the LEC design -­

retail stores and high schools -- only rank 5th and 11th in percentage reduction, 

respectively, among the 11 building types, as reported in Table 11-2. 

Table 11-5 Statewide Change in Annual Energy Use for One Year of Construction, 

Idaho 

Building Subcategory m 2 ft2 Standard Edition 

Type Weighting (1000s) (1000s) LEC 

kWh kBtu 

APART04 44.9 % 21 225 -307 982 -1 051 583
 

APART06 55.1 % 26 276 -405 457 -1 384 405
 

HOTEL15 100.0 % 44 475 -836 589 -2 856 476 

HIGHS02 100.0 % 127 1369 -1 691 060 -5 774 006 

OFFIC03 37.4 % 54 577 -1 119 489 -3 822 416 

OFFIC08 40.4 % 58 622 -1 091 942 -3 728 358 

OFFIC16 22.2 % 32 342 -720 644 -2 460 587 

RETAIL1 100.0 % 140 1505 -2 344 554 -8 005 314 

RSTRNT1 100.0 % 9 99 -380 359 -1 298 710 

Total 510 5490 -8 898 075 -30 381 855 

Note: Dormitories are excluded because no such floor area category is reported 

in the construction data. 

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Idaho 

11.2.2 Energy Costs 

Table 11-6 reports the average per unit change in energy costs by building type for the 

LEC design. Energy costs are calculated using the annual energy use, state average 

energy cost rates, and regional energy price escalation rates as defined in Section 3.2. 

Table 11-6 Average Per Unit Change in Energy Costs, 10-Year, Idaho 

Building Standard Edition 

Type LEC 

$/m2 $/ft2 

APART04 -$8.04 -$0.75 

APART06 -$8.92 -$0.83 

DORMI04 -$7.24 -$0.67 

DORMI06 -$9.36 -$0.87 

HOTEL15 -$9.37 -$0.87 

HIGHS02 -$10.77 -$1.00 

OFFIC03 -$9.32 -$0.87 

OFFIC08 -$9.67 -$0.90 

OFFIC16 -$11.59 -$1.08 

RETAIL1 -$8.23 -$0.76 

RSTRNT1 -$21.05 -$1.96 

Table 11-7 reports the statewide changes in total energy costs by building type and 

building design, which account for one year’s worth of new construction evaluated over 

10 years. All building types realize energy cost savings for the LEC design, with a 

statewide reduction in energy costs of $4.8 million for 10 years of building operation. 

Assuming that the buildings considered in this study, which represent 63.6 % of all new 

commercial floor space in the state, are generally representative of the entire new 

commercial building stock in the state, the results for the LEC design can be extrapolated 

to estimate the total statewide energy cost savings of $7.6 million over the 10-year study 

period. 

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Idaho 

Table 11-7 Statewide Change in Energy Costs for One Year of Construction, 

10-Year, Idaho 

Building Subcategory m 2 ft2 Standard Edition
 

Type Weighting (1000s) (1000s) LEC
 

APART04 44.9 % 21 225 -$168 362 

APART06 55.1 % 26 276 -$228 678 

HOTEL15 100.0 % 44 475 -$413 642 

HIGHS02 100.0 % 127 1369 -$1 185 996 

OFFIC03 37.4 % 54 577 -$576 926 

OFFIC08 40.4 % 58 622 -$558 751 

OFFIC16 22.2 % 32 342 -$368 403 

RETAIL1 100.0 % 140 1505 -$1 150 752 

RSTRNT1 100.0 % 9 99 -$192 788 

Total 510 5490 -$4 844 297 

Note: Dormitories are excluded because no such floor area category is 

reported in the construction data. 

11.2.3 Energy-related Carbon Emissions 

Table 11-8 reports the average reduction in energy-related carbon emissions over 10 

years, per m 

2 (ft2

), by building type. The carbon emissions estimation approach is defined 

in Section 5.3. 

Table 11-8 Average Per Unit Change in Carbon Emissions, 10-Year, Idaho 

Building Standard Edition 

Type LEC 

kg/m2 lb/ft2 

APART04 -77.4 -15.9 

APART06 -85.9 -17.6 

DORMI04 -69.6 -14.3 

DORMI06 -90.1 -18.4 

HOTEL15 -90.2 -18.5 

HIGHS02 -89.9 -18.4 

OFFIC03 -103.6 -21.2 

OFFIC08 -93.1 -19.1 

OFFIC16 -111.5 -22.8 

RETAIL1 -79.2 -16.2 

RSTRNT1 -202.5 -41.5 

Table 11-9 applies the Table 11-8 results to one year’s worth of new building 

construction in the state to estimate the statewide reduction in carbon emissions from 

adoption of the LEC design. The total reduction in carbon emissions ranges widely across 

building designs, and is highly correlated with the total reduction in energy use. The LEC 

design decreases carbon emissions for all building types. The adoption of the LEC design 

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Idaho 

results in savings of 46 630 metric tons over the 10-year study period for one year’s 

worth of new commercial construction for these building types. Assuming that the 

buildings considered in this study are generally representative of the entire new 

commercial building stock in the state, the results for the LEC design can be extrapolated 

to estimate the statewide reduction in carbon emissions of 69 910 metric tons over the 

10-year study period. 

Table 11-9 Statewide Change in Total Carbon Emissions for One Year of 

Construction, 10-Year, Idaho – Metric Tons 

Building Subcategory m 2 ft2 Standard Edition
 

Type Weighting (1000s) (1000s)
 LEC 

APART04 44.9 % 21 225 -1621 

APART06 55.1 % 26 276 -2202 

HOTEL15 100.0 % 44 475 -3979 

HIGHS02 100.0 % 127 1369 -11 434 

OFFIC03 37.4 % 54 577 -5551 

OFFIC08 40.4 % 58 622 -5376 

OFFIC16 22.2 % 32 342 -3545 

RETAIL1 100.0 % 140 1505 -11 068 

RSTRNT1 100.0 % 9 99 -1855 

Total 510 5490 -46 630 

Note: Dormitories are excluded because no such floor area category is 

reported in the construction data. 

11.2.4 Life-Cycle Costs 

Table 11-10 reports the average change in life-cycle cost over 10 years, per m2 (ft2

), by 

building type. As discussed in Section 5.2, life-cycle costs include construction costs, 

maintenance, repair, and replacement costs, energy costs, and residual values. 

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Idaho 

Table 11-10 Average Per Unit Change in Life-Cycle Costs, 10-Year, Idaho
 

Building Standard Edition 

Type LEC 

$/m2 $/ft2 

APART04 $7.74 $0.72 

APART06 $7.69 $0.71 

DORMI04 -$10.73 -$1.00 

DORMI06 $5.20 $0.48 

HOTEL15 $6.58 $0.61 

HIGHS02 -$1.78 -$0.17 

OFFIC03 -$21.36 -$1.98 

OFFIC08 -$19.00 -$1.76 

OFFIC16 $6.45 $0.60 

RETAIL1 $6.99 $0.65 

RSTRNT1 -$34.04 -$3.16 

Table 11-11 applies the Table 11-10 results to one year’s worth of new building 

construction in the state to estimate statewide changes in life-cycle costs from adoption of 

the LEC design. Total changes in life-cycle costs over the 10-year study period vary 

across building type, with 4 of 9 building types realizing reductions in life-cycle costs. 

Overall, the LEC design results in a decrease of $947 944 in statewide life-cycle costs 

relative to ASHRAE 90.1-2007. Three-story and 8-story office buildings realize the 

greatest reductions in life-cycle costs ($1.1 million each). Retail stores realize the greatest 

increase in life-cycle costs ($977 602). Assuming that the buildings considered in this 

study are generally representative of the entire new commercial building stock in the 

state, the results for the LEC design can be extrapolated to estimate a statewide decrease 

in life-cycle costs of $1.5 million over the 10-year study period. 

Table 11-11 Statewide Change in Life-Cycle Costs for One Year of Construction, 

10-Year, Idaho 

Building Subcategory m 2 ft2 Standard Edition
 

Type Weighting (1000s) (1000s) LEC
 

APART04 44.9 % 21 225 $162 002
 

APART06 55.1 % 26 276 $197 018
 

HOTEL15 100.0 % 44 475 $290 222 

HIGHS02 100.0 % 127 1369 -$226 410 

OFFIC03 37.4 % 54 577 -$1 144 028 

OFFIC08 40.4 % 58 622 -$1 097 521 

OFFIC16 22.2 % 32 342 $205 001 

RETAIL1 100.0 % 140 1505 $977 602 

RSTRNT1 100.0 % 9 99 -$311 829 

Total 510 5490 -$947 944 

Note: Dormitories are excluded because no such floor area category is 

reported in the construction data. 

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Idaho 

11.3 State Summary 

Idaho has adopted ASHRAE 90.1-2007 as its state energy code for commercial buildings. 

On average, adopting the LEC design reduces energy use, energy costs, and 

energy-related carbon emissions, and does so in a life-cycle cost-effective manner. Based 

on the average annual new construction in the state from 2003 to 2007 and a 10-year 

study period, adopting the LEC design as the state’s energy code for commercial 

buildings would lead to statewide energy use savings of 139.9 GWh (477.8 GBtu), 

energy cost savings of $7.6 million, and carbon emissions reductions of 69 910 metric 

tons while decreasing life-cycle costs of $1.5 million for one year’s worth of commercial 

building construction. 

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Montana 

12 Montana 

Montana has adopted ASHRAE 90.1-2007 as its state energy code, and is located in the 

Mountain Census Division and Climate Zone 6B. Table 12-1 provides an overview of 

Montana’s simulated energy use keyed to building types and energy codes. Average 

energy use varies across building types and building designs. The 8-story office building 

uses the least amount of energy at 88 kWh/m2 to 106 kWh/m2 (28 kBtu/ft2 to 34 kBtu/ft2) 

annually. The high school uses the greatest amount of energy at 248 kWh/m2 to 

274 kWh/m2 (79 kBtu/ft2 to 87 kBtu/ft2) annually. 

Table 12-1 Average Annual Energy Use by Building Type and Standard Editions, 

Montana 

Building 

Type 

Standard Edition 

2007 

kWh/m2 kBtu/ft2 

LEC 

kWh/m2 kBtu/ft2 

APART04 

APART06 

169 54 

166 53 

153 48 

151 48 

DORMI04 

DORMI06 

137 43 

186 59 

119 38 

170 54 

HOTEL15 183 58 166 53 

HIGHS02 274 87 248 79 

OFFIC03 

OFFIC08 

OFFIC16 

118 38 

106 34 

171 54 

97 31 

88 28 

151 48 

RETAIL1 137 43 115 36 

RSTRNT1 184 58 140 44 

The detailed analysis for this state reports the changes in energy use, energy costs, 

energy-related carbon emissions, and life-cycle costs from adoption of the LEC design. 

The results are reported in terms of average percentage savings on a statewide and 

city-by-city basis and as total savings on a statewide basis. 

12.1 Percentage Savings 

Changes in percentage terms allow for direct comparisons across building types and 

locations within a state. This section discusses the average percentage changes from 

investing in the LEC design in the state of Montana. 

12.1.1 Statewide Building Comparison 

Table 12-2 shows the percentage change in energy use, energy costs, energy-related 

carbon emissions, and life-cycle costs for the LEC design relative to ASHRAE 90.1-2007. 

There is significant variation in the change in energy use for the LEC design relative to 

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ASHRAE 90.1-2007, ranging from -8.6 % to -24.1 % depending on the building type with 

an overall average of -13.3 %. The 6-story dormitory realizes the lowest reduction in 

energy use while restaurants realize the greatest reduction in energy use. 

Table 12-2 Average Percentage Change from Adoption of Standard Editions, 10­

Year, Montana 

Building LEC 

Type Energy Use Energy Cost Carbon LCC 

APART04 -9.6 -15.2 -14.5 0.6 

APART06 -9.5 -15.1 -14.4 0.6 

DORMI04 -12.9 -17.1 -16.6 -1.2 

DORMI06 -8.6 -13.6 -12.9 0.3 

HOTEL15 -9.4 -11.5 -11.3 0.4 

HIGHS02 -9.7 -13.9 -13.3 -0.6 

OFFIC03 -18.0 -20.1 -19.9 -1.9 

OFFIC08 -16.9 -18.1 -18.0 -1.5 

OFFIC16 -11.7 -12.5 -12.5 0.4 

RETAIL1 -16.0 -17.7 -17.5 0.1 

RSTRNT1 -24.1 -28.9 -28.4 -1.4 

Average -13.3 -16.7 -16.3 -0.4 

There is a significant variation in the average percentage change in energy costs for the 

LEC design relative to ASHRAE 90.1-2007, ranging from -11.5 % to -28.9 % depending 

on the building type with an average of -16.7 % for 10 years of building operation. The 

energy costs are reduced by a greater percentage than energy use because the energy 

efficiency measures decrease electricity consumption by a greater percentage than natural 

gas consumption. The greater relative percentage reduction in electricity consumption 

leads to greater decreases energy costs because natural gas is cheaper on a per unit of 

energy basis relative to electricity. 

There is significant variation in the average change in energy-related carbon emissions 

across building types for the LEC design relative to ASHRAE 90.1-2007, ranging 

from -11.3 % to -28.4 % with an average of -16.3 %. For the LEC design, the percentage 

reduction in carbon emissions is greater than the percentage reduction in energy use for 

all 11 building types because the energy efficiency measures decrease electricity 

consumption by a greater percentage than natural gas consumption. The greater relative 

reduction in electricity leads to a greater reduction in carbon emissions because natural 

gas has a lower average carbon emissions rate than electricity. 

The percentage change in life-cycle costs varies across building types, ranging 

from -1.9 % to 0.6 % for a 10-year study period. Five of the 11 building types realize 

reductions in life-cycle costs, with 3-story office buildings realizing the greatest 

percentage reduction in life-cycle costs, while 4- and 6-story apartment buildings realize 

the largest increases in life-cycle costs (0.6 %). Based on the overall average percentage 

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Montana 

change of -0.4 % in life-cycle costs, the LEC design may be cost-effective if the state 

adopted it as its state energy code for commercial buildings. 

12.1.2 City Comparisons 

Simulations are run for nine cities located in Montana, all of which are located in Zone 

6B: Billings, Cut Bank, Glasgow, Great Falls, Helena, Kalispell, Lewistown, Miles City, 

and Missoula. While the nine cities are located in the same climate zone, the results may 

still vary for two reasons. First, cities within the same climate zone may have some 

variation in the local climate, which can lead to variation in energy consumption. Second, 

construction material and labor costs may vary significantly by locality. 

Table 12-3 shows the percentage change in energy use, energy costs, energy-related 

carbon emissions, and life-cycle costs for the LEC design relative to ASHRAE 90.1-2007 

for each city in the state. The average percentage change in energy use for all building 

types from adopting the LEC design varies slightly across cities, ranging from -12.4 % to 

-15.5 % with an overall average of -13.3 %. 

Table 12-3 Average Percentage Change from Adoption of Newer Standard Editions 

by City, 10-Year, Montana 

Cities Zone LEC 

Energy Use Energy Cost Carbon LCC 

Billings 6B -13.7 -17.1 -16.9 -0.6 

Cut Bank 6B -13.1 -16.7 -16.3 -0.3 

Glasgow 6B -12.4 -15.8 -15.5 -0.3 

Great Falls 6B -13.3 -16.7 -16.4 -0.6 

Helena 6B -13.1 -16.8 -16.5 -0.2 

Kalispell 6B -15.5 -17.9 -17.6 -0.1 

Lewistown 6B -13.0 -16.6 -16.3 -0.4 

Miles City 6B -13.0 -16.4 -16.1 -0.6 

Missoula 6B -12.6 -16.4 -16.1 -0.2 

Average -13.3 -16.7 -16.4 -0.4 

The average percentage change in energy costs for all building types varies minimally 

across cities, ranging from -15.8 % to -17.9 % for 10 years of operation. For all cities, 

reductions in energy costs are greater than reductions in energy use because the 

percentage reduction in electricity consumption is greater than the reduction in natural 

gas consumption. Repeating the pattern, the average percentage change in carbon 

emissions for all building types also varies slightly across cities, ranging from -15.5 % 

to -17.6 %. Changes in life-cycle costs for all building types vary slightly across cities, 

ranging from -0.1 % to -0.6 %. 

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Montana 

12.2 Total Savings 

How much can Montana save, in terms of energy use, energy costs, and carbon 

emissions, from adopting a more stringent state energy code for commercial buildings? 

What are the life-cycle costs associated with the new energy code adoption? To answer 

these questions, it is necessary to estimate savings per unit of floor area for each building 

type in the state. 

12.2.1 Energy Use 

Table 12-4 reports the average per unit change in annual energy use by building type and 

building design in the state.28 The reduction per m2 (ft2

) is multiplied by the estimated m2 

(ft2) of new construction of each building type, and Table 12-5 reports the estimated 

average annual floor area of new construction and the total annual reduction in energy 

use for each building type. The weightings within a category (e.g., small, medium, and 

large office buildings) are based on the national average percentage of new building 

construction for the category that is represented by each subcategory.29 

Table 12-4 Average Per Unit Change in Annual Energy Use, Montana 

Building Standard Edition 

Type LEC 

kWh/m2 kBtu/ft2 

APART04 -16.1 -5.1 

APART06 -15.8 -5.0 

DORMI04 -17.5 -5.6 

DORMI06 -15.9 -5.0 

HOTEL15 -17.3 -5.5 

HIGHS02 -21.4 -6.8 

OFFIC03 -26.7 -8.5 

OFFIC08 -17.9 -5.7 

OFFIC16 -19.9 -6.3 

RETAIL1 -21.9 -7.0 

RSTRNT1 -44.3 -14.0 

The adoption of the LEC design as the state’s energy code for commercial buildings 

would save energy for all building types and 3.3 GWh (11.4 GBtu) of total energy use 

annually for one year’s worth of new construction for these building types. Assuming that 

the buildings considered in this study, which represent 63.5 % of all new commercial 

floor space in the state, are generally representative of the entire new commercial 

building stock in the state, the results can be extrapolated to estimate statewide savings to 

28 A simple average for a state is used because no data for a weighted average is available regarding the
 

amount of new construction on a city-by-city basis.
 

29 State-level subcategory data are not available.
 

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Montana 

be 5.2 GWh (17.9 GBtu) per year. These savings imply 52.5 GWh (179.1 GBtu) in 

energy use savings over the 10-year study period. 

The change in energy use varies across building types. The building types that have the 

greatest percentage reductions are not always the same buildings that lead to the greatest 

total reductions for the state. Instead the building types that represent a greater amount of 

new floor area realize larger changes in energy use. The greatest total reductions are 

realized by retail stores and high schools because they represent 33.5 % and 23.0 %, 

respectively, of the combined new construction in the state for the building types in this 

study while all other building types represent 15.5 % or less. The amount of new 

construction overwhelms the relative percentage changes in energy use. The building 

types that lead to the greatest estimated total reductions in energy use for the LEC design 

– retail stores and high schools -- only rank 4th and 7th in percentage reduction, 

respectively, among the 11 building types, as reported in Table 12-2. 

Table 12-5 Statewide Change in Annual Energy Use for One Year of Construction, 

Montana 

Building Subcategory m 2 ft2 Standard Edition 

Type Weighting (1000s) (1000s) LEC 

kWh kBtu 

APART04 44.9 % 4 43 -64 705 -220 931 

APART06 55.1 % 5 53 -77 568 -264 852 

HOTEL15 100.0 % 24 253 -405 658 -1 385 089 

HIGHS02 100.0 % 35 374 -928 840 -3 171 460 

OFFIC03 37.4 % 11 120 -237 944 -812 443 

OFFIC08 40.4 % 12 129 -215 134 -734 561 

OFFIC16 22.2 % 7 71 -131 680 -449 612 

RETAIL1 100.0 % 51 545 -1 109 215 -3 787 336 

RSTRNT1 100.0 % 4 39 -160 404 -547 688 

Total 151 1627 -3 331 148 -11 373 972 

Note: Dormitories are excluded because no such floor area category is reported 

in the construction data. 

12.2.2 Energy Costs 

Table 12-6 reports the average per unit change in energy costs by building type for the 

LEC design. Energy costs are calculated using the annual energy use, state average 

energy cost rates, and regional energy price escalation rates as defined in Section 3.2. 

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Montana 

Table 12-6 Average Per Unit Change in Energy Costs, 10-Year, Montana
 

Building Standard Edition 

Type LEC 

$/m2 $/ft2 

APART04 -$10.29 -$0.96 

APART06 -$10.19 -$0.95 

DORMI04 -$9.70 -$0.90 

DORMI06 -$10.15 -$0.94 

HOTEL15 -$8.71 -$0.81 

HIGHS02 -$12.64 -$1.17 

OFFIC03 -$14.31 -$1.33 

OFFIC08 -$10.97 -$1.02 

OFFIC16 -$10.65 -$0.99 

RETAIL1 -$11.60 -$1.08 

RSTRNT1 -$25.22 -$2.34 

Table 12-7 reports the statewide changes in total energy costs by building type and 

building design, which account for one year’s worth of new construction evaluated over 

10 years. All building types realize energy cost savings for the LEC design, with 

statewide reductions in energy costs of $1.8 million for 10 years of building operation. 

Assuming that the buildings considered in this study, which represent 63.5 % of all new 

commercial floor space in the state, are generally representative of the entire new 

commercial building stock in the state, the results for the LEC design can be extrapolated 

to estimate the total statewide energy cost savings of $2.9 million over the 10-year study 

period. 

Table 12-7 Statewide Change in Energy Costs for One Year of Construction, 

10-Year, Montana 

Building Subcategory m 2 ft2 Standard Edition
 

Type Weighting (1000s) (1000s)
 LEC 

APART04 44.9 % 4 43 -$41 320 

APART06 55.1 % 5 53 -$50 121 

HOTEL15 100.0 % 24 253 -$204 793 

HIGHS02 100.0 % 35 374 -$497 334 

OFFIC03 37.4 % 11 120 -$140 793 

OFFIC08 40.4 % 12 129 -$131 762 

OFFIC16 22.2 % 7 71 -$70 384 

RETAIL1 100.0 % 51 545 -$586 907 

RSTRNT1 100.0 % 4 39 -$91 395 

Total 151 1627 -$1 814 810 

Note: Dormitories are excluded because no such floor area category 

is reported in the construction data. 

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Montana 

12.2.3 Energy-related Carbon Emissions 

Table 12-8 reports the average reduction in energy-related carbon emissions over 10 

years, per m 2 (ft2

), by building type. The carbon emissions estimation approach is defined 

in Section 5.3. 

Table 12-8 Average Per Unit Change in Carbon Emissions, 10-Year, Montana 

Building Standard Edition 

Type LEC 

kg/m2 lb/ft2 

APART04 -89.9 -18.4 

APART06 -88.9 -18.2 

DORMI04 -85.8 -17.6 

DORMI06 -88.7 -18.2 

HOTEL15 -77.8 -15.9 

HIGHS02 -127.0 -26.0 

OFFIC03 -111.1 -22.8 

OFFIC08 -96.2 -19.7 

OFFIC16 -94.5 -19.4 

RETAIL1 -103.1 -21.1 

RSTRNT1 -222.6 -45.6 

Table 12-9 applies the Table 12-8 results to one year’s worth of new building 

construction in the state to estimate statewide reductions in carbon emissions from 

adoption of the LEC design. The total reduction in carbon emissions ranges widely across 

building designs and is highly correlated with total reductions in energy use. The LEC 

design decreases carbon emissions for all building types. The adoption of the LEC design 

results in savings of 16 083 metric tons over the 10-year study period for one year’s 

worth of new commercial construction for these building types. Assuming that the 

buildings considered in this study are generally representative of the entire new 

commercial building stock in the state, the results for the LEC design can be extrapolated 

to estimate statewide reductions in carbon emissions of 24 113 metric tons over the 

10-year study period. 

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Montana 

Table 12-9 Statewide Change in Total Carbon Emissions for One Year of 

Construction, 10-Year, Montana – Metric Tons 

Building Subcategory m 2 ft2 Standard Edition
 

Type Weighting (1000s) (1000s)
 LEC 

APART04 44.9 % 4 43 -361
 

APART06 55.1 % 5 53 -438
 

HOTEL15 100.0 % 24 253 -1829 

HIGHS02 100.0 % 35 374 -4415 

OFFIC03 37.4 % 11 120 -1238 

OFFIC08 40.4 % 12 129 -1155 

OFFIC16 22.2 % 7 71 -625 

RETAIL1 100.0 % 51 545 -5216 

RSTRNT1 100.0 % 4 39 -807 

Total 151 1627 -16 083 

Note: Dormitories are excluded because no such floor area category is 

reported in the construction data. 

12.2.4 Life-Cycle Costs 

Table 12-10 reports the average change in life-cycle cost over 10 years, per m2 (ft2), by 

building type. As discussed in Section 5.2, life-cycle costs include construction costs, 

maintenance, repair, and replacement costs, energy costs, and residual values. 

Table 12-10 Average Per Unit Change in Life-Cycle Costs, 10-Year, Montana 

Building Standard Edition 

Type LEC 

$/m2 $/ft2 

APART04 $5.33 $0.49 

APART06 $5.99 $0.56 

DORMI04 -$10.65 -$0.99 

DORMI06 $3.39 $0.31 

HOTEL15 $3.88 $0.36 

HIGHS02 -$4.53 -$0.42 

OFFIC03 -$14.61 -$1.36 

OFFIC08 -$11.66 -$1.08 

OFFIC16 $2.82 $0.26 

RETAIL1 $0.56 $0.05 

RSTRNT1 -$16.74 -$1.56 

Table 12-11 applies the Table 12-10 results to one year’s worth of new building 

construction in the state to estimate changes in statewide life-cycle costs from adoption of 

the LEC design. Total changes in life-cycle costs over the 10-year study period vary 

across building type, with 4 of 9 building types realizing reductions in life-cycle costs. 

Overall, the LEC design results in a decrease of $332 355 in statewide life-cycle costs 

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Montana 

relative to ASHRAE 90.1-2007. Three-story office buildings, high schools, and 8-story 

office buildings realize the greatest statewide decreases in life-cycle costs 

(-$162 813, -$157 629, and -$140 036, respectively) while hotels realize the largest 

increase in life-cycle costs of $91 122. Assuming that the buildings considered in this 

study are generally representative of the entire new commercial building stock in the 

state, the results for the LEC design can be extrapolated to estimate a statewide decrease 

in life-cycle costs of $523 393 over the 10-year study period. 

Table 12-11 Statewide Change in Life-Cycle Costs for One Year of Construction, 

10-Year, Montana 

Building Subcategory m 2 ft2 Standard Edition
 

Type Weighting (1000s) (1000s) LEC
 

APART04 44.9 % 4 43 $21 395 

APART06 55.1 % 5 53 $29 480 

HOTEL15 100.0 % 24 253 $91 122 

HIGHS02 100.0 % 35 374 -$157 629 

OFFIC03 37.4 % 11 120 -$162 813 

OFFIC08 40.4 % 12 129 -$140 036 

OFFIC16 22.2 % 7 71 $18 650 

RETAIL1 100.0 % 51 545 $28 132 

RSTRNT1 100.0 % 4 39 -$60 656 

Total 151 1627 -$332 355 

Note: Dormitories are excluded because no such floor area category 

is reported in the construction data. 

12.3 State Summary 

Montana has adopted ASHRAE 90.1-2007 as its state energy code for commercial 

buildings. On average, adopting the LEC design reduces energy use, energy costs, and 

energy-related carbon emissions in a cost-effective manner. Based on the average annual 

new construction in the state from 2003 to 2007 and a 10-year study period, adopting the 

LEC design as the state’s energy code for commercial buildings would lead to statewide 

energy use savings of 52.5 GWh (179.1 GBtu), energy cost savings of $2.9 million, and 

carbon emissions reductions of 24 113 metric tons while decreasing life-cycle costs by 

$523 393 million for one year’s worth of commercial building construction. 

109
 
Montana 

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Nevada 

13 Nevada 

Nevada is one of two states in the West Census Region that have adopted ASHRAE 

90.1-2004 as their state energy code for commercial buildings, is located in the Mountain 

Census Division, and spans two climate zones (Zone 3B and Zone 4B). Table 13-1 

provides an overview of Nevada’s simulated energy use keyed to building types and 

energy standard edition. Average energy use varies across building types and building 

designs. The 8-story office building uses the least amount of energy at 79 kWh/m2 to 

102 kWh/m2 (25 kBtu/ ft2 to 32 kBtu/ft2) annually. The high school uses the greatest 

amount of energy at 188 kWh/m2 to 206 kWh/m2 (60 kBtu/ ft2 to 65 kBtu/ft2

) annually. 

Table 13-1 Average Annual Energy Use by Building Type and Standard Editions, 

Nevada 

Building 

Type 

Standard Edition 

2004 2007 LEC 

kWh/m2 kBtu/ft2 kWh/m2 kBtu/ft2 kWh/m2 kBtu/ft2 

APART04 139 44 133 42 119 38 

APART06 136 43 131 42 116 37 

DORMI04 108 34 103 33 90 29 

DORMI06 150 48 146 46 129 41 

HOTEL15 133 42 141 45 121 38 

HIGHS02 206 65 199 63 188 60 

OFFIC03 111 35 104 33 83 26 

OFFIC08 102 32 99 31 79 25 

OFFIC16 134 42 141 45 117 37 

RETAIL1 128 41 115 37 101 32 

RSTRNT1 177 56 156 49 115 36 

The detailed analysis for this state reports the changes in energy use, energy costs, 

energy-related carbon emissions, and life-cycle costs from adoption of increasingly 

stringent energy codes. The results are reported in terms of average percentage savings on 

a statewide and city-by-city basis, and as total savings on a statewide basis. 

13.1 Percentage Savings 

Changes in percentage terms allow for direct comparisons across building type and 

location within a state. This section discusses the average percentage changes from 

investing in more energy efficient designs in the state of Nevada. 

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Nevada 

13.1.1 Energy Use 

Table 13-2 shows a large variation in percentage changes in energy use for ASHRAE 

90.1-2007 relative to ASHRAE 90.1-2004, ranging from 6.0 % to -11.3 % with an average 

of -3.4 %. For the high-rise, 100 % glazed buildings (16-story office building and 

15-story hotel), ASHRAE 90.1-2007 is actually less energy efficient than ASHRAE 

90.1-2004 because the maximum window U-factor and SHGC requirements in Zone 3B 

and Zone 4B for buildings with fenestration accounting for greater than 40 % of wall 

surface area is less stringent for ASHRAE 90.1-2007 relative to ASHRAE 90.1-2004. The 

100 % glazing amplifies the energy loss enough to overwhelm the energy efficiency 

gains obtained from other measures, such as increased insulation R-values. 

Table 13-2 Average Percentage Change in Energy Use from Adoption of Newer 

Standard Editions, Nevada 

Building Standard Edition 

Type 2007 LEC 

APART04 -4.3 -14.5 

APART06 -3.7 -14.9 

DORMI04 -5.0 -17.1 

DORMI06 -2.7 -14.1 

HOTEL15 6.0 -8.8 

HIGHS02 -3.4 -9.5 

OFFIC03 -5.7 -25.3 

OFFIC08 -3.2 -23.0 

OFFIC16 5.8 -12.5 

RETAIL1 -10.0 -21.0 

RSTRNT1 -11.3 -35.1 

Average -3.4 -17.8 

The LEC design realizes percentage changes in energy use relative to ASHRAE 

90.1-2004, ranging from -8.8 % to -35.1 % with an average of -17.8 %. Similar to the 

ASHRAE 90.1-2007 design, the smallest reductions in energy use for the LEC design 

occurs in the 16-story office building and hotel. Additionally, the high school realizes 

smaller reductions in energy use because of its unique occupant activity, significant 

occupancy during the school year and minimal occupancy during the summer. 

13.1.2 Energy Costs 

Table 13-3 shows significant variation in the percentage changes in average energy costs 

for ASHRAE 90.1-2007 relative to ASHRAE 90.1-2004, ranging from 7.0 % to -6.7 % 

depending on the building type, with an average of -1.7 %. As with energy use savings, 

adopting ASHRAE 90.1-2007 results in an increase in energy costs relative to ASHRAE 

90.1-2004 for the two high-rise buildings. For these two building types, the percentage 

increase in energy costs is greater than the increase in energy use because electricity 

consumption increases by a greater percentage than natural gas consumption. The greater 

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Nevada 

relative increase in electricity further increases energy costs because electricity is more 

expensive per unit of energy. The remaining nine building types realize smaller 

percentage reductions in energy costs than the reductions in energy use because adopting 

the ASHRAE 90.1-2007 design decreases natural gas consumption by a greater percentage 

than electricity consumption. 

Table 13-3 Average Percentage Change in Energy Costs, 10-Year, Nevada 

Building Standard Edition 

Type 2007 LEC 

APART04 -3.7 -20.7 

APART06 -3.2 -22.9 

DORMI04 -3.5 -21.1 

DORMI06 -2.6 -22.1 

HOTEL15 6.8 -14.7 

HIGHS02 -2.7 -18.2 

OFFIC03 -2.7 -26.7 

OFFIC08 -1.3 -23.4 

OFFIC16 7.0 -16.0 

RETAIL1 -6.4 -21.9 

RSTRNT1 -6.7 -38.6 

Average -1.7 -22.4 

The LEC design realizes greater reductions in energy costs than the ASHRAE 90.1-2007 

design, with the average percentage change by building type ranging from -14.7 % 

to -38.6 % with an overall average of -22.4 % for 10 years of building operation. The 

reductions in energy costs are greater than the reductions in energy use for all 11 building 

types because electricity consumption is decreased by a greater percentage than natural 

gas consumption. For 6 of the 11 building types, the energy efficiency measures increase 

natural gas consumption while decreasing electricity consumption. The shift is most 

prevalent for the high school, where the increase in natural gas consumption offsets 

30.2 % of the reduction in electricity consumption, and results in a percentage reduction 

in energy costs that is nearly twice the percentage reduction in energy use. The LEC 

design incorporates daylighting into the building design for all climate zones and 

overhangs for cities in Zone 3 and Zone 4, which decreases the building’s internal and 

external heat gains, respectively. The shift in energy use from electricity to natural gas 

consumption to meet the greater heating loads decreases energy costs because natural gas 

is cheaper on a per unit of energy basis relative to electricity. 

13.1.3 Energy-related Carbon Emissions Reduction 

Table 13-4 shows significant variation in the average percentage change in energy-related 

carbon emissions for the ASHRAE 90.1-2007 design across building types, ranging from 

6.7 % to -8.1 % with an average of -2.2 %. As would be expected, a more energy 

efficient building design results in greater reductions in carbon emissions. However, the 

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Nevada 

carbon emissions reductions (increases) are smaller (larger) than the energy use 

reductions (increases) for all 11 building types for the ASHRAE 90.1-2007 design. 

Similar to the reductions in energy costs, this result is due to the fuel source of the 

reductions in energy use. For the nine building types that realize smaller reductions in 

carbon emissions than energy use, the percentage reduction in natural gas consumption is 

greater than the reduction in electricity. For the two building types that realize a greater 

percentage increase in carbon emissions than energy use, natural gas consumption is 

increased by a smaller percentage than electricity consumption. 

The LEC design leads to significant changes in average carbon emissions, ranging 

from -13.0 % to -37.7 % depending on the building type with an average of -21.0 % 

across all building types. The LEC design realizes a greater percentage reduction in 

natural gas consumption than electricity consumption for all 11 building types, which 

leads to additional carbon emissions reductions because natural gas has a lower average 

carbon emissions rate than electricity. 

Table 13-4 Average Percentage Change in Energy-related Carbon Emissions, 10­

Year, Nevada 

Building Standard Edition 

Type 2007 LEC 

APART04 -3.9 -18.8 

APART06 -3.4 -20.5 

DORMI04 -3.9 -19.9 

DORMI06 -2.6 -19.6 

HOTEL15 6.5 -13.0 

HIGHS02 -3.0 -15.4 

OFFIC03 -3.5 -26.3 

OFFIC08 -1.8 -23.3 

OFFIC16 6.7 -15.1 

RETAIL1 -7.4 -21.7 

RSTRNT1 -8.1 -37.7 

Average -2.2 -21.0 

13.1.4 Life-Cycle Costs 

The most cost-effective building design for each building type is bolded in Table 13-5. 

Based on the life-cycle costs over a 10-year study period, the ASHRAE 90.1-2007 design 

realizes the lowest life-cycle costs for three building types while the LEC design has the 

lowest life-cycle costs for six building types. The current state energy code, ASHRAE 

90.1-2004, results in lower life-cycle costs for the hotel and 16-story office building. 

Adopting the ASHRAE 90.1-2007 and LEC designs lead to percentage reductions in lifecycle costs for all building types except the two high-rise buildings. Given that the 

average percentage changes in life-cycle costs are -0.4 % and -1.6 %, respectively, it is 

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Nevada 

possible that both the ASHRAE 90.1-2007 and LEC designs are cost-effective for the state 

to adopt as its state energy code for commercial buildings. 

Table 13-5 Average Percentage Change in Life-Cycle Costs, 10-Year, Nevada 

Building Standard Edition 

Type 2007 LEC 

APART04 -0.4 -0.1 

APART06 -0.3 -0.1 

DORMI04 -0.7 -1.9 

DORMI06 -0.2 -0.4 

HOTEL15 0.6 0.7 

HIGHS02 -0.4 -1.5 

OFFIC03 -0.4 -4.3 

OFFIC08 -0.4 -3.6 

OFFIC16 0.8 0.7 

RETAIL1 -1.2 -0.6 

RSTRNT1 -1.7 -6.0 

Average -0.4 -1.6 

13.1.5 City Comparisons 

Simulations are run for six cities located in Nevada: Las Vegas in Zone 3B and Elko, Ely, 

Reno, Tonopah, and Winnemucca in Zone 4B. The results vary across cities within the 

state for several reasons. First, the state is covered by two climate zones. The ASHRAE 

90.1 building design requirements vary across climate zone, and will impact the relative 

energy efficiency of the building. Second, cities within the same climate zone still have 

some variation in the local climate, which can lead to variation in energy consumption. 

Third, construction material and labor costs vary by locality. 

As can be seen in Table 13-6, the average reduction in energy use for all building types 

from adopting the ASHRAE 90.1-2007 varies little both across and within climate zones. 

For the ASHRAE 90.1-2007 design, the percentage change in average energy use ranges 

from -2.7 % to -4.1 % with an average of -3.4 %. For the LEC design, the percentage 

change varies both within and across climate zones, with average energy use ranging 

from -15.7 % to -21.3 % and an average of -17.8 %. Across both building design 

alternatives, the city in the warmer climate zone (Zone 3B) realizes slightly greater 

reductions in energy use than the cities in the colder climate zone (Zone 4B). 

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Table 13-6 Average Percentage Change in Energy Use from Adoption of Newer 

Standard Editions by City, Nevada 

Cities Zone Standard Edition 

2007 LEC 

Las Vegas 3B -2.7 -21.3 

Elko 4B -4.0 -16.4 

Ely 4B -4.1 -15.7 

Reno 4B -3.1 -17.9 

Tonopah 4B -2.9 -18.3 

Winnemucca 4B -3.6 -17.2 

Average -3.4 -17.8 

The variations in energy costs across cities are a result of two factors, the reductions in 

energy use and the fuel source of the reduction. Table 13-7 shows that the average 

reduction in energy costs for all building types varies across climate zones, but minimally 

within Zone 4B. For the ASHRAE 90.1-2007 design, the percentage change in average 

energy costs ranges from -1.0 % to -3.7 % with an average of -1.7 %. The average 

percentage change in energy costs is greater for the city in Zone 3B (-3.7 %) than the 

cities in Zone 4B (-1.3 %). For the LEC design, the percentage change in average energy 

costs ranges from -21.2 % to -25.0 % with an average of -22.4 %. The city in Zone 3B 

realizes a slightly greater change in energy use (-25.0 %) than the cities in Zone 4B (­

21.9 %). 

Table 13-7 Average Percentage Change in Energy Costs by City, 10-Year, Nevada 

Cities Zone Standard Edition 

2007 LEC 

Las Vegas 3B -3.7 -25.0 

Elko 4B -1.6 -21.2 

Ely 4B -1.6 -20.8 

Reno 4B -1.1 -22.7 

Tonopah 4B -1.0 -22.8 

Winnemucca 4B -1.4 -21.8 

Average -1.7 -22.4 

Table 13-8 reports energy-related carbon emissions by city for the state. For all cities, the 

more energy efficient designs result in greater reductions in carbon emissions. The city in 

Zone 3B realizes a slightly greater average percentage change in carbon emissions than 

the cities in Zone 4B for ASHRAE 90.1-2007, -3.7 % versus -2.4 %. The average 

emissions reduction varies across cities for the LEC design, ranging from 24.5 % to 

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Nevada 

20.1 %. Similar to the ASHRAE 90.1-2007 design, the city in Zone 3B realizes a greater 

reduction than the cities in Zone 4B. 

Table 13-8 Average Percentage Change in Carbon Emissions by City, Nevada 

Cities Zone Standard Edition 

2007 LEC 

Las Vegas 3B -3.7 -24.5 

Elko 4B -2.7 -20.1 

Ely 4B -2.7 -19.6 

Reno 4B -2.0 -21.7 

Tonopah 4B -1.9 -22.0 

Winnemucca 4B -2.4 -20.9 

Average -2.6 -21.4 

The data reported in Table 13-9 show that the ASHRAE 90.1-2007 design decreases 

life-cycle costs across all cities, with changes in life-cycle costs ranging minimally 

from -0.3 % to -0.4 %. The LEC design realizes the greatest reduction in life-cycle costs 

across all cities in the state. There is variation in the average percentage changes in lifecycle costs across climate zones, with Las Vegas in Zone 3B realizing a smaller 

percentage reduction in life-cycle costs than cities in Zone 4B. 

Table 13-9 Average Percentage Change in Life-Cycle Costs by City, 10-Year, 

Nevada 

Cities Zone Standard Edition 

2007 LEC 

Las Vegas 3B -0.4 -1.2 

Elko 4B -0.4 -1.8 

Ely 4B -0.3 -1.6 

Reno 4B -0.4 -1.4 

Tonopah 4B -0.3 -1.7 

Winnemucca 4B -0.4 -1.7 

Average -0.4 -1.6 

13.2 Total Savings 

How much can Nevada save, in terms of energy use, energy costs, and carbon emissions, 

from adopting a more stringent state energy code for commercial buildings? What are the 

life-cycle costs associated with the new energy code adoption? To answer these 

questions, it is necessary to estimate savings per unit of floor area for each building type 

in the state. 

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Nevada 

13.2.1 Energy Use 

Table 13-10 reports the average per unit change in annual energy use by building type 

and building design in the state.30 The reduction per m2 (ft2

) is multiplied by the 

estimated m2 (ft2

) of new construction of each building type, and Table 13-11 reports the 

estimated average annual floor area of new construction and the total annual reduction in 

energy use for each building type. The weightings within a category (e.g., small, medium, 

and large office buildings) are based on the national average percentage of new building 

construction for the category that is represented by each subcategory.31 

Table 13-10 Average Per Unit Change in Annual Energy Use, Nevada 

Building Standard Edition 

Type 2007 

kWh/m2 kBtu/ft2 

LEC 

kWh/m2 kBtu/ft2 

APART04 

APART06 

-5.9 -1.9 

-5.0 -1.6 

-19.8 -6.3 

-19.9 -6.3 

DORMI04 

DORMI06 

-5.4 -1.7 

-3.9 -1.2 

-18.4 -5.8 

-20.7 -6.6 

HOTEL15 7.8 2.5 -11.5 -3.6 

HIGHS02 -6.3 -2.0 -27.9 -8.9 

OFFIC03 

OFFIC08 

OFFIC16 

-7.3 -2.3 

-3.3 -1.0 

7.8 2.5 

-18.4 -5.8 

-23.5 -7.5 

-16.6 -5.3 

RETAIL1 -12.9 -4.1 -26.9 -8.5 

RSTRNT1 -20.5 -6.5 -62.0 -19.7 

The annual reduction in energy use shown in Table 13-11 ranges widely across building 

designs, but the ASHRAE 90.1-2007 and LEC designs both decrease total energy use 

across the state. The adoption of the ASHRAE 90.1-2007 design results in reductions of 

7.3 GWh (24.9 GBtu) annually. ASHRAE 90.1-2007 increases total energy use for the 

two high-rise buildings and decreases total energy use for the other seven building types. 

30 A simple average for a state is used because no data for a weighted average is available regarding the
 

amount of new construction on a city-by-city basis.
 

31 State-level subcategory data are not available.
 

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Nevada 

Table 13-11 Statewide Change in Annual Energy Use for One Year of Construction, 

Nevada 

Building Subcategory m 2 ft2 Standard Edition 

Type Weighting (1000s) (1000s) 2007 LEC 

kWh kBtu kWh kBtu 

APART04 44.9 % 258 2774 -1 530 929 -5 227 248 -5 107 986 -17 440 860
 

APART06 55.1 % 316 3397 -1 562 606 -5 335 407 -6 287 910 -21 469 630
 

HOTEL15 100.0 % 593 6379 4 640 470 15 844 562 -6 815 515 -23 271 098 

HIGHS02 100.0 % 192 2067 -1 399 357 -4 778 006 -3 527 286 -12 043 670 

OFFIC03 37.4 % 122 1310 -768 263 -2 623 181 -3 399 442 -11 607 158 

OFFIC08 40.4 % 131 1413 -433 470 -1 480 054 -3 084 549 -10 531 977 

OFFIC16 22.2 % 72 777 561 639 1 917 676 -1 201 279 -4 101 682 

RETAIL1 100.0 % 476 5129 -6 169 715 -21 066 059 -12 797 093 -43 694 779 

RSTRNT1 100.0 % 31 338 -644 528 -2 200 695 -1 947 196 -6 648 564 

Total 2191 23 585 -7 306 758 -24 948 412 -44 168 256 -150 809 417 

Note: Dormitories are excluded because no such floor area category is reported in the construction data. 

The adoption of the LEC design as the state’s energy code for commercial buildings 

would save 44.2 GWh (150.8 GBtu) of total statewide energy use annually for one year’s 

worth of new construction for these building types. Assuming that the buildings 

considered in this study, which represent 62.3 % of all new commercial floor space in the 

state, are generally representative of the entire new commercial building stock in the 

state, the results can be extrapolated to estimate the statewide savings to be 70.9 GWh 

(242.1 GBtu) per year. These savings imply over 709.0 GWh (2420.7 GBtu) in energy 

savings over the 10-year study period. 

For both building designs, the greatest total changes in energy use are realized by retail 

stores and hotels because they represent 21.7 % and 27.0 %, respectively, of the 

combined new construction in the state for the building types in this study while all other 

building types represent 14.4 % or less. The amount of new construction overwhelms the 

relative percentage changes in energy use. The building types that lead to the greatest 

estimated changes in energy use for the LEC design -- retail stores and hotels -- only rank 

4th and 11th in percentage reduction, respectively, among the 11 building types, as 

reported in Table 13-2. 

13.2.2 Energy Costs 

Table 13-12 reports the average per unit change in energy costs by building type and 

building design. Energy costs are calculated using the annual energy use, state average 

energy cost rates, and regional energy price escalation rates as defined in Section 3.2. 

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Nevada 

Table 13-12 Average Per Unit Change in Energy Costs, 10-Year, Nevada
 

Building Standard Edition 

Type 2007 

$/m2 $/ft2 

LEC 

$/m2 $/ft2 

APART04 

APART06 

-$3.12 -$0.29 

-$2.71 -$0.25 

-$16.76 -$1.56 

-$18.53 -$1.72 

DORMI04 

DORMI06 

-$2.35 -$0.22 

-$2.47 -$0.23 

-$14.02 -$1.30 

-$19.68 -$1.83 

HOTEL15 $5.37 $0.50 -$11.62 -$1.08 

HIGHS02 -$2.20 -$0.20 -$21.57 -$2.00 

OFFIC03 

OFFIC08 

OFFIC16 

-$3.02 -$0.28 

-$1.09 -$0.10 

$6.62 $0.61 

-$19.91 -$1.85 

-$18.55 -$1.72 

-$15.25 -$1.42 

RETAIL1 -$5.40 -$0.50 -$18.40 -$1.71 

RSTRNT1 -$7.67 -$0.71 -$44.11 -$4.10 

Table 13-13 reports the statewide changes in total energy costs by building type and 

building design, which account for one year’s worth of new construction evaluated over 

10 years of building operation. Overall, reductions in energy costs are greater for the 

more energy efficient building designs: $1.8 million and $37.2 million for adopting the 

ASHRAE 90.1-2007 and LEC designs, respectively. The increase in energy use for the 

high-rise buildings leads to an increase in energy costs for those buildings for ASHRAE 

90.1-2007. All building types realize energy cost savings for the LEC design. The energy 

cost savings are highly correlated with the energy use savings. Assuming that the 

buildings considered in this study, which represent 62.3 % of all new commercial floor 

space in the state, are generally representative of the entire new commercial building 

stock in the state, the results for the ASHRAE 90.1-2007 and LEC design can be 

extrapolated to estimate the total statewide energy cost savings of $2.9 million and 

$59.7 million over the 10-year study period, respectively. 

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Nevada 

Table 13-13 Statewide Change in Energy Costs for One Year of Construction, 

10-Year, Nevada 

Building Subcategory m 2 ft2 Standard Edition
 

Type Weighting (1000s) (1000s) 2007 LEC
 

APART04 44.9 % 258 2774 -$803 834 -$4 317 991
 

APART06 55.1 % 316 3397 -$855 198 -$5 847 875
 

HOTEL15 100.0 % 593 6379 $3 184 735 -$6 887 978 

HIGHS02 100.0 % 192 2067 -$579 821 -$3 823 697 

OFFIC03 37.4 % 122 1310 -$267 936 -$2 625 327 

OFFIC08 40.4 % 131 1413 -$142 705 -$2 435 331 

OFFIC16 22.2 % 72 777 $477 927 -$1 101 376 

RETAIL1 100.0 % 476 5129 -$2 571 122 -$8 765 631 

RSTRNT1 100.0 % 31 338 -$240 992 -$1 386 024 

Total 2191 23 585 -$1 798 946 -$37 191 230 

Note: Dormitories are excluded because no such floor area category is reported in 

the construction data. 

13.2.3 Energy-related Carbon Emissions 

Table 13-14 reports the average reduction in energy-related carbon emissions over 10 

years, per m 

2 (ft2

), by building type and building design. The carbon emissions estimation 

approach is defined in Section 5.3. 

Table 13-14 Average Per Unit Change in Carbon Emissions, 10-Year, Nevada 

Building Standard Edition 

Type 2007 

kg/m2 lb/ft2 

LEC 

kg/m2 lb/ft2 

APART04 

APART06 

-20.8 -4.3 

-17.9 -3.7 

-98.2 -20.1 

-106.4 -21.8 

DORMI04 

DORMI06 

-16.7 -3.4 

-15.6 -3.2 

-84.3 -17.3 

-112.5 -23.0 

HOTEL15 33.2 6.8 -65.6 -13.4 

HIGHS02 -21.9 -4.5 -110.9 -22.7 

OFFIC03 

OFFIC08 

OFFIC16 

-17.1 -3.5 

-8.7 -1.8 

38.7 7.9 

-129.2 -26.5 

-110.5 -22.6 

-87.8 -18.0 

RETAIL1 -39.1 -8.0 -113.6 -23.3 

RSTRNT1 -57.9 -11.9 -269.7 -55.2 

Table 13-15 applies the Table 13-14 results to one year’s worth of new building 

construction in the state to estimate statewide reduction in carbon emissions from 

adoption of more energy efficient codes. The total reduction in carbon emissions ranges 

widely across building designs, but the ASHRAE 90.1-2007 and LEC designs decrease 

carbon emissions for the state as a whole. The adoption of ASHRAE 90.1-2007 saves 

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Nevada 

16 408 metric tons over a 10-year study period. The adoption of the LEC design 

decreases carbon emissions by 218 244 metric tons over the 10-year study period for one 

year’s worth of new commercial construction for these building types. Assuming that the 

buildings considered in this study are generally representative of the entire new 

commercial building stock in the state, the results for the ASHRAE 90.1-2007 and LEC 

designs can be extrapolated to estimate statewide reductions in carbon emissions of 

24 600 metric tons and 327 203 metric tons over the 10-year study period, respectively. 

Table 13-15 Statewide Change in Total Carbon Emissions for One Year of 

Construction, 10-Year, Nevada – Metric Tons 

Building Subcategory m 2 ft2 Standard Edition
 

Type Weighting (1000s) (1000s) 2007 LEC
 

APART04 44.9 % 258 2774 -5369 -25 316
 

APART06 55.1 % 316 3397 -5637 -33 573
 

HOTEL15 100.0 % 593 6379 19 660 -38 875 

HIGHS02 100.0 % 192 2067 -4207 -21 291 

OFFIC03 37.4 % 122 1310 -2082 -15 725 

OFFIC08 40.4 % 131 1413 -1136 -14 509 

OFFIC16 22.2 % 72 777 2798 -6342 

RETAIL1 100.0 % 476 5129 -18 615 -54 140 

RSTRNT1 100.0 % 31 338 -1820 -8474 

Total 2191 23 585 -16 408 -218 244 

Note: Dormitories are excluded because no such floor area category is 

reported in the construction data. 

13.2.4 Life-Cycle Costs 

Table 13-16 reports the average change in life-cycle cost over 10 years, per m2 (ft2

), by 

building type and building design. As discussed in Section 5.2, life-cycle costs include 

construction costs, maintenance, repair, and replacement costs, energy costs, and residual 

values. 

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Nevada 

Table 13-16 Average Per Unit Change in Life-Cycle Costs, 10-Year, Nevada
 

Building Standard Edition 

Type 2007 

$/m2 $/ft2 

LEC 

$/m2 $/ft2 

APART04 

APART06 

-$4.01 -$0.37 

-$3.33 -$0.31 

-$0.86 

-$1.49 

-$0.08 

-$0.14 

DORMI04 

DORMI06 

-$6.86 -$0.64 

-$2.73 -$0.25 

-$18.49 

-$4.21 

-$1.72 

-$0.39 

HOTEL15 

HIGHS02 

$5.81 $0.54 

-$2.95 -$0.27 

$7.08 

-$12.71 

$0.66 

-$1.18 

OFFIC03 

OFFIC08 

OFFIC16 

-$3.59 -$0.33 

-$3.36 -$0.31 

$6.19 $0.58 

-$34.35 

-$30.18 

$5.45 

-$3.19 

-$2.80 

$0.51 

RETAIL1 -$7.59 -$0.71 -$4.04 -$0.38 

RSTRNT1 -$21.87 -$2.03 -$79.92 -$7.43 

Table 13-17 applies the Table 13-16 results to one year’s worth of new building 

construction in the state to estimate the change in statewide life-cycle costs from adoption 

of more energy-efficient codes. ASHRAE 90.1-2007 results in total reductions in 

life-cycle costs of $3.9 million over the 10-year study period relative to ASHRAE 

90.1-2004 for the building types considered in this study. The LEC design leads to a 

decrease in total statewide life-cycle costs of $11.1 million, while reducing life-cycle 

costs for 7 of 9 building types. The ASHRAE 90.1-2007 and LEC designs lead to an 

increase in life-cycle costs for hotels and 16-story office buildings. Assuming that the 

buildings considered in this study are generally representative of the entire new 

commercial building stock in the state, the results for the ASHRAE 90.1-2007 and LEC 

designs can be extrapolated to estimate total reductions in life-cycle costs of $6.3 million 

and $17.9 million over the 10-year study period, respectively. 

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Nevada 

Table 13-17 Statewide Change in Life-Cycle Costs for One Year of Construction, 

10-Year, Nevada 

Building Subcategory m 2 ft2 Standard Edition
 

Type Weighting (1000s) (1000s) 2007 LEC
 

APART04 44.9 % 258 2774 -$1 032 318 -$222 870 

APART06 55.1 % 316 3397 -$1 049 523 -$471 027 

HOTEL15 100.0 % 593 6379 $3 445 646 $4 194 240 

HIGHS02 100.0 % 192 2067 -$566 368 -$2 440 774 

OFFIC03 37.4 % 122 1310 -$436 650 -$4 181 010 

OFFIC08 40.4 % 131 1413 -$440 493 -$3 962 275 

OFFIC16 22.2 % 72 777 $447 185 $393 917 

RETAIL1 100.0 % 476 5129 -$3 617 242 -$1 924 864 

RSTRNT1 100.0 % 31 338 -$687 082 -$2 511 213 

Total 2191 23 585 -$3 936 845 -$11 125 878 

Note: Dormitories are excluded because no such floor area category is reported in the 

construction data. 

13.3 State Summary 

Nevada is one of two states in the West Census Region that have adopted ASHRAE 

90.1-2004 as their current state energy code for commercial buildings. On average, 

adopting ASHRAE 90.1-2007 leads to reductions in energy use, energy costs, and 

energy-related carbon emissions, and does so in a cost-effective manner. Based on the 

average annual new construction in the state from 2003 to 2007 and a 10-year study 

period, adopting ASHRAE 90.1-2007 as the state’s energy code would lead to energy 

savings of 117.3 GWh (400.5 GBtu), energy cost savings of $2.9 million, carbon 

emissions reductions of 24 600 metric tons, and life-cycle cost savings of $6.3 million. 

The life-cycle cost savings are greater than the energy cost savings. The relaxation of the 

U-factor and SHGC requirements from ASHRAE 90.1-2004 to ASHRAE 90.1-2007 

decreases the costs of construction by a greater amount than the other energy efficiency 

measures increase construction costs, while still reducing total energy costs. The LEC 

design would lead to even greater impacts for the state with savings of 709.0 GWh 

(2420.7 GBtu), energy cost savings of $59.7 million, and carbon emissions reductions of 

327 203 metric tons for one year’s worth of commercial building construction while 

decreasing life-cycle costs by $17.9 million. 

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New Mexico 

14 New Mexico 

New Mexico has adopted ASHRAE 90.1-2007 as its state energy code, is located in the 

Mountain Census Division, and spans three climate zones (Zone 3B, Zone 4B, and 

Zone 5B). Table 14-1 provides an overview of New Mexico’s simulated energy use 

keyed to building types and energy codes. Average energy use varies across building 

types and building designs. The 4-story dormitory uses the least amount of energy at 77 

kWh/m2 to 91 kWh/m2 (24 kBtu/ft2 to 29 kBtu/ft2

) annually. The high school uses the 

greatest amount of energy at 145 kWh/m2 to 161 kWh/m2 (46 kBtu/ft2 to 51 kBtu/ft2) 

annually. 

Table 14-1 Average Annual Energy Use by Building Type and Standard Edition, 

New Mexico 

Building 

Type 

Standard Edition 

2007 

kWh/m2 kBtu/ft2 

LEC 

kWh/m2 kBtu/ft2 

APART04 

APART06 

118 37 

117 37 

102 32 

100 32 

DORMI04 

DORMI06 

91 29 

131 42 

77 24 

111 35 

HOTEL15 124 39 104 33 

HIGHS02 161 51 145 46 

OFFIC03 

OFFIC08 

OFFIC16 

101 32 

99 31 

134 42 

78 25 

78 25 

108 34 

RETAIL1 105 33 89 28 

RSTRNT1 151 48 104 33 

The detailed analysis for this state reports the changes in energy use, energy costs, 

energy-related carbon emissions, and life-cycle costs from adoption of the LEC design. 

The results are reported in terms of average percentage savings on a statewide and 

city-by-city basis and as total savings on a statewide basis. 

14.1 Percentage Savings 

Changes in percentage terms allow for direct comparisons across building types and 

locations within a state. This section discusses the average percentage changes from 

investing in the LEC design in the state of New Mexico. 

14.1.1 Statewide Building Comparison 

Table 14-2 shows the percentage change in energy use, energy costs, energy-related 

carbon emissions, and life-cycle costs for the LEC design relative to ASHRAE 90.1-2007. 

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New Mexico 

There is significant variation in the change in energy use for the LEC design relative to 

ASHRAE 90.1-2007, ranging from -9.6 % to -31.4 % depending on the building type with 

an overall average of -17.7 %. High schools realize the lowest reductions in energy use 

while restaurants realize the greatest reductions in energy use. 

Table 14-2 Average Percentage Change from Adoption of Newer Standard 

Editions, 10-Year, New Mexico 

Building LEC 

Type Energy Use Energy Cost Carbon LCC 

APART04 -13.6 -20.0 -20.0 0.5 

APART06 -15.1 -23.0 -23.0 0.3 

DORMI04 -15.3 -19.8 -19.8 -1.6 

DORMI06 -15.2 -22.8 -22.9 -0.1 

HOTEL15 -15.7 -21.1 -21.1 0.4 

HIGHS02 -9.6 -19.8 -19.9 -1.0 

OFFIC03 -23.3 -25.5 -25.6 -3.1 

OFFIC08 -21.4 -22.5 -22.5 -2.8 

OFFIC16 -18.9 -21.7 -21.7 0.3 

RETAIL1 -15.6 -18.9 -18.9 0.1 

RSTRNT1 -31.4 -36.6 -36.6 -4.3 

Average -17.7 -22.9 -22.9 -1.0 

There is a significant variation in the average percentage change in energy costs for the 

LEC design relative to ASHRAE 90.1-2007, ranging from -18.9 % to -36.6 % depending 

on the building type with an average of -22.9 % for 10 years of building operation. The 

energy costs are reduced by a greater percentage than energy use because the energy 

efficiency measures decrease electricity consumption by a greater percentage than natural 

gas consumption. In fact, adopting the LEC design leads to an increase in natural gas 

consumption and a decrease in electricity consumption for all 11 building types. The shift 

is most prevalent for the high school, where the increase in natural gas consumption 

offsets 39.7 % of the reduction in electricity consumption, and results in a percentage 

reduction in energy costs that is over twice the percentage reduction in energy use. The 

LEC design incorporates daylighting and overhangs into the building design for cities in 

Zone 3, Zone 4, and Zone 5, which decreases the building’s internal and external heat 

gains, respectively. The shift in energy use from electricity to natural gas consumption to 

meet the greater heating loads decreases energy costs because natural gas is cheaper on a 

per unit of energy basis relative to electricity. 

There is significant variation in the average change in energy-related carbon emissions 

across building types for the LEC design relative to ASHRAE 90.1-2007, ranging 

from -18.9 % to -36.6 % with an overall average of -22.9 %. As mentioned above, the 

energy efficiency measures decrease electricity consumption while increasing natural gas 

consumption for all 11 building types. The combination of the reduction in total energy 

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New Mexico 

use and the shift in energy use from electricity consumption to natural gas consumption 

leads to greater reductions in carbon emissions than reductions in energy use. 

The percentage change in life-cycle costs varies across building types, ranging 

from -4.3 % to 0.5 % for a 10-year study period. Six of the 11 building types realize 

reductions in life-cycle costs. Based on the overall average percentage change of -1.0 % 

in life-cycle costs, the LEC design may be cost-effective if the state adopted it as its state 

energy code for commercial buildings. 

14.1.2 City Comparisons 

Simulations are run for three cities located in New Mexico: Roswell in Zone 3B and 

Albuquerque and Tucumcari in Zone 4B. New Mexico has no significant population 

centers located in Zone 5B. The results may vary across cities within New Mexico for 

several reasons. First, the cities selected for the state cover two climate zones. The 

ASHRAE 90.1 building design requirements vary across climate zones and may impact 

the relative energy efficiency of the building. Second, cities within the same climate zone 

still have some variation in the local climate, which can lead to variation in energy 

consumption. Third, construction material and labor costs vary by locality. 

Table 14-3 shows the percentage change in energy use, energy costs, energy-related 

carbon emissions, and life-cycle costs for the LEC design relative to ASHRAE 90.1-2007 

for each city in the state. The average percentage changes in energy use for all building 

types from adopting the LEC design vary minimally across cities, ranging from -16.7 % 

to -18.3 % with an overall average of -17.7 %. The city located in Zone 3B realizes 

slightly lower reductions in energy use relative to cities in Zone 4B. 

Table 14-3 Average Percentage Change from Adoption of Newer Standard Editions 

by City, 10-Year, New Mexico 

Cities Zone LEC 

Energy Use Energy Cost Carbon LCC 

Roswell 3B -16.7 -21.7 -22.0 -0.9 

Albuquerque 4B -18.2 -23.7 -23.9 -1.2 

Tucumcari 4B -18.3 -23.2 -23.5 -1.0 

Average -17.7 -22.9 -23.1 -1.0 

The average percentage change in energy costs for all building types also varies 

minimally across cities, ranging from -21.7 % to -23.7 % for 10 years of operation. For 

all cities, percentage reductions in energy costs are greater than percentage reductions in 

energy use because the percentage reduction in electricity consumption is greater than the 

reduction in natural gas consumption. Repeating the pattern, the average percentage 

change in carbon emissions for all building types also varies minimally across cities, 

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New Mexico 

ranging from -22.0 % to -23.9 %. Reductions in life-cycle costs for all building types 

vary minimally across cities, with the percentage change in life-cycle costs ranging 

from -0.9 % to -1.2 %. 

14.2 Total Savings 

How much can New Mexico save, in terms of energy use, energy costs, and carbon 

emissions, from adopting a more stringent state energy code for commercial buildings? 

What are the life-cycle costs associated with the new energy code adoption? To answer 

these questions, it is necessary to estimate savings per unit of floor area for each building 

type in the state. 

14.2.1 Energy Use 

Table 14-4 reports the average per unit change in annual energy use by building type and 

building design in the state.32 The reduction per m2 (ft2

) is multiplied by the estimated m2 

(ft2) of new construction of each building type, and Table 14-5 reports the estimated 

average annual floor area of new construction and the total annual reduction in energy 

use for each building type. The weightings within a category (e.g., small, medium, and 

large office buildings) are based on the national average percentage of new building 

construction for the category that is represented by each subcategory.33 

Table 14-4 Average Per Unit Change in Annual Energy Use, New Mexico 

Building Standard Edition 

Type LEC 

kWh/m2 kBtu/ft2 

APART04 -16.0 -5.1 

APART06 -17.7 -5.6 

DORMI04 -13.8 -4.4 

DORMI06 -19.9 -6.3 

HOTEL15 -19.4 -6.1 

HIGHS02 -23.6 -7.5 

OFFIC03 -15.4 -4.9 

OFFIC08 -21.2 -6.7 

OFFIC16 -25.3 -8.0 

RETAIL1 -16.3 -5.2 

RSTRNT1 -47.5 -15.1 

The adoption of the LEC design as the state’s energy code for commercial buildings 

would save energy for all building types and 10.2 GWh (34.8 GBtu) of total energy use 

32 A simple average for a state is used because no data for a weighted average is available regarding the
 

amount of new construction on a city-by-city basis.
 

33 State-level subcategory data are not available.
 

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New Mexico 

annually for one year’s worth of new construction for these building types. Assuming that 

the buildings considered in this study, which represent 66.2 % of all new commercial 

floor space in the state, are generally representative of the entire new commercial 

building stock in the state, the results can be extrapolated to estimate statewide savings to 

be 15.4 GWh (52.5 GBtu) per year. These savings imply 153.7 GWh (525.0 GBtu) in 

energy use savings over the 10-year study period. 

The total change in energy use varies across building types. The building types that have 

the greatest percentage reductions in energy use are not always the same buildings that 

lead to the greatest total reductions for the state. Instead the building types that represent 

a greater amount of new floor area realize the largest reductions in energy use. The 

greatest total reductions are realized by high schools and retail stores because they 

represent 28.3 % and 27.8 %, respectively, of the combined new construction in the state 

for the building types in this study while all other building types represent 15.5 % or less. 

The amount of new construction overwhelms the relative percentage changes in energy 

use. The building types that lead to the greatest estimated reduction in energy use for the 

LEC design -- retail stores and high schools -- only rank 6th and 11th in percentage 

reduction, respectively, among the 11 building types, as reported in Table 14-2. 

Table 14-5 Statewide Change in Annual Energy Use for One Year of Construction, 

New Mexico 

Building Subcategory m 2 ft2 Standard Edition 

Type Weighting (1000s) (1000s) LEC 

kWh kBtu 

APART04 44.9 % 8 86 -128 185 -437 677
 

APART06 55.1 % 10 105 -173 748 -593 249
 

HOTEL15 100.0 % 84 900 -1 620 405 -5 532 758 

HIGHS02 100.0 % 150 1619 -2 323 480 -7 933 361 

OFFIC03 37.4 % 46 497 -1 090 572 -3 723 681 

OFFIC08 40.4 % 50 536 -1 057 242 -3 609 880 

OFFIC16 22.2 % 27 295 -692 784 -2 365 461 

RETAIL1 100.0 % 153 1647 -2 500 657 -8 538 319 

RSTRNT1 100.0 % 12 134 -590 866 -2 017 472 

Total 541 5819 -10 177 939 -34 751 859 

Note: Dormitories are excluded because no such floor area category is reported 

in the construction data. 

14.2.2 Energy Costs 

Table 14-6 reports the average per unit change in energy costs by building type for the 

LEC design. Energy costs are calculated using the annual energy use, state average 

energy cost rates, and regional energy price escalation rates as defined in Section 3.2. 

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New Mexico 

Table 14-6 Average Per Unit Change in Energy Costs, 10-Year, New Mexico
 

Building Standard Edition 

Type LEC 

$/m2 $/ft2 

APART04 -$12.07 -$1.12 

APART06 -$14.04 -$1.30 

DORMI04 -$9.79 -$0.91 

DORMI06 -$15.44 -$1.43 

HOTEL15 -$13.55 -$1.26 

HIGHS02 -$16.22 -$1.51 

OFFIC03 -$15.05 -$1.40 

OFFIC08 -$14.35 -$1.33 

OFFIC16 -$17.48 -$1.62 

RETAIL1 -$11.57 -$1.07 

RSTRNT1 -$31.62 -$2.94 

Table 14-7 reports the statewide changes in total energy costs by building type and 

building design, which account for one year’s worth of new construction evaluated over 

10 years. All building types realize energy cost savings for the LEC design, with a 

statewide reduction in energy costs of $7.7 million for 10 years of building operation. 

Assuming that the buildings considered in this study, which represent 66.2 % of all new 

commercial floor space in the state, are generally representative of the entire new 

commercial building stock in the state, the results for the LEC design can be extrapolated 

to estimate the total statewide energy cost savings of $11.7 million over the 10-year study 

period. 

Table 14-7 Statewide Change in Energy Costs for One Year of Construction, 

10-Year, New Mexico 

Building Subcategory m 2 ft2 Standard Edition
 

Type Weighting (1000s) (1000s)
 LEC 

APART04 44.9 % 8 86 -$96 487 

APART06 55.1 % 10 105 -$137 422 

HOTEL15 100.0 % 84 900 -$1 132 771 

HIGHS02 100.0 % 150 1619 -$2 263 571 

OFFIC03 37.4 % 46 497 -$748 677 

OFFIC08 40.4 % 50 536 -$714 142 

OFFIC16 22.2 % 27 295 -$478 623 

RETAIL1 100.0 % 153 1647 -$1 769 882 

RSTRNT1 100.0 % 12 134 -$393 624 

Total 541 5819 -$7 735 199 

Note: Dormitories are excluded because no such floor area category 

is reported in the construction data. 

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New Mexico 

14.2.3 Energy-related Carbon Emissions 

Table 14-8 reports the average reduction in energy-related carbon emissions over 10 

years, per m 2 (ft2

), by building type. The carbon emissions estimation approach is defined 

in Section 5.3. 

Table 14-8 Average Per Unit Change in Carbon Emissions, 10-Year, New Mexico 

Building Standard Edition 

Type LEC 

kg/m2 lb/ft2 

APART04 -151.9 -31.1 

APART06 -176.7 -36.2 

DORMI04 -123.2 -25.2 

DORMI06 -194.4 -39.8 

HOTEL15 -170.5 -34.9 

HIGHS02 -189.6 -38.8 

OFFIC03 -204.1 -41.8 

OFFIC08 -180.5 -37.0 

OFFIC16 -219.9 -45.0 

RETAIL1 -145.5 -29.8 

RSTRNT1 -397.7 -81.4 

Table 14-9 applies the Table 14-8 results to one year’s worth of new building 

construction in the state to estimate the statewide reduction in carbon emissions from 

adoption of the LEC design. The total reduction in carbon emissions ranges widely across 

building designs and is highly correlated with the total reduction in energy use. The LEC 

design decreases carbon emissions for all building types. The adoption of the LEC design 

results in savings of 97 353 metric tons over the 10-year study period for one year’s 

worth of new commercial construction for these building types. Assuming that the 

buildings considered in this study are generally representative of the entire new 

commercial building stock in the state, the results for the LEC design can be extrapolated 

to estimate statewide reductions in carbon emissions of 145 956 metric tons over the 

10-year study period. 

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New Mexico 

Table 14-9 Statewide Change in Total Carbon Emissions for One Year of 

Construction, 10-Year, New Mexico – Metric Tons 

Building Subcategory m 2 ft2 Standard Edition
 

Type Weighting (1000s) (1000s)
 LEC 

APART04 44.9 % 8 86 -1214 

APART06 55.1 % 10 105 -1730 

HOTEL15 100.0 % 84 900 -14 251 

HIGHS02 100.0 % 150 1619 -28 520 

OFFIC03 37.4 % 46 497 -9418 

OFFIC08 40.4 % 50 536 -8982 

OFFIC16 22.2 % 27 295 -6021 

RETAIL1 100.0 % 153 1647 -22 267 

RSTRNT1 100.0 % 12 134 -4951 

Total 541 5819 -97 353 

Note: Dormitories are excluded because no such floor area category is 

reported in the construction data. 

14.2.4 Life-Cycle Costs 

Table 14-10 reports the average change in life-cycle cost over 10 years, per m2 (ft2), by 

building type. As discussed in Section 5.2, life-cycle costs include construction costs, 

maintenance, repair, and replacement costs, energy costs, and residual values. 

Table 14-10 Average Per Unit Change in Life-Cycle Costs, 10-Year, New Mexico 

Building Standard Edition 

Type LEC 

$/m2 $/ft2 

APART04 $4.41 $0.41 

APART06 $2.89 $0.27 

DORMI04 -$14.37 -$1.33 

DORMI06 -$0.49 -$0.05 

HOTEL15 $3.51 $0.33 

HIGHS02 -$8.07 -$0.75 

OFFIC03 -$23.77 -$2.21 

OFFIC08 -$22.22 -$2.06 

OFFIC16 $2.21 $0.21 

RETAIL1 $0.39 $0.04 

RSTRNT1 -$54.62 -$5.07 

Table 14-11 applies the Table 14-10 results to one year’s worth of new building 

construction in the state to estimate changes in statewide life-cycle costs from adoption of 

the LEC design. Total changes in life-cycle costs over the 10-year study period vary 

across building type, with 4 of 9 building types realizing reductions in life-cycle costs. 

Overall, the LEC design results in a decrease of $3.6 million in statewide life-cycle costs 

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New Mexico 

relative to ASHRAE 90.1-2007. High schools realize the greatest statewide decreases in 

life-cycle costs ($1.2 million) while hotels, 16-story office buildings, and retail stores 

realize the greatest increases in life-cycle costs ($293 252, $60 502, and 59 978, 

respectively). Assuming that the buildings considered in this study are generally 

representative of the entire new commercial building stock in the state, the results for the 

LEC design can be extrapolated to estimate a statewide decrease in life-cycle costs of 

$5.5 million over the 10-year study period. 

Table 14-11 Statewide Change in Life-Cycle Costs for One Year of Construction, 

10-Year, New Mexico 

Building Subcategory m 2 ft2 Standard Edition
 

Type Weighting (1000s) (1000s) LEC
 

APART04 44.9 % 8 86 $35 278
 

APART06 55.1 % 10 105 $28 293
 

HOTEL15 100.0 % 84 900 $293 252 

HIGHS02 100.0 % 150 1619 -$1 213 908 

OFFIC03 37.4 % 46 497 -$1 096 795 

OFFIC08 40.4 % 50 536 -$1 105 995 

OFFIC16 22.2 % 27 295 $60 502 

RETAIL1 100.0 % 153 1647 $59 978 

RSTRNT1 100.0 % 12 134 -$680 003 

Total 541 5819 -$3 619 397 

Note: Dormitories are excluded because no such floor area category is 

reported in the construction data. 

14.3 State Summary 

New Mexico has adopted ASHRAE 90.1-2007 as its state energy code for commercial 

buildings. On average, adopting the LEC design reduces energy use, energy costs, and 

energy-related carbon emissions, and does so in a cost-effective manner. Based on the 

average annual new construction in the state from 2003 to 2007 and a 10-year study 

period, adopting the LEC design as the state’s energy code for commercial buildings 

would lead to statewide energy use savings of 153.7 GWh (525.0 GBtu), energy cost 

savings of $11.7 million, and carbon emissions reductions of 145 956 metric tons while 

decreasing life-cycle costs by $5.5 million for one year’s worth of commercial building 

construction. 

133
 
New Mexico 

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Oregon 

15 Oregon 

Oregon has adopted ASHRAE 90.1-2007 as its state energy code, is located in the Pacific 

Census Division, and spans two climate zones (Zone 4C and Zone 5B). Table 15-1 

provides an overview of Oregon’s simulated energy use keyed to building types and 

energy codes. Average energy use varies across building types and building designs. The 

8-story office building uses the least amount of energy at 72 kWh/m2 to 91 kWh/m2 (23 

kBtu/ft2 to 29 kBtu/ft2

) annually. The high school uses the greatest amount of energy at 

179 kWh/m2 to 188 kWh/m2 (57 kBtu/ft2 to 60 kBtu/ft2). 

Table 15-1 Average Annual Energy Use by Building Type and Standard Edition, 

Oregon 

Building 

Type 

Standard Edition 

2007 

kWh/m2 kBtu/ft2 

LEC 

kWh/m2 kBtu/ft2 

APART04 

APART06 

124 39 

125 40 

112 35 

111 35 

DORMI04 

DORMI06 

96 30 

136 43 

84 27 

122 39 

HOTEL15 133 42 115 37 

HIGHS02 188 60 179 57 

OFFIC03 

OFFIC08 

OFFIC16 

96 30 

91 29 

132 42 

76 24 

72 23 

109 34 

RETAIL1 104 33 90 29 

RSTRNT1 142 45 102 32 

The detailed analysis for this state reports the changes in energy use, energy costs, 

energy-related carbon emissions, and life-cycle costs from adoption of a more stringent 

energy code for commercial buildings. The results are reported in terms of average 

percentage savings on a statewide and city-by-city basis and as total savings on a 

statewide basis. 

15.1 Percentage Savings 

Changes in percentage terms allow for direct comparisons across building types and 

locations within a state. This section discusses the average percentage changes from 

investing in a more energy efficient design in the state of Oregon. 

15.1.1 Statewide Building Comparison 

Table 15-2 shows the percentage change in energy use, energy costs, energy-related 

carbon emissions, and life-cycle costs for the LEC design relative to ASHRAE 90.1-2007. 

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Oregon 

There is significant variation in the percentage change in energy use for the LEC design 

relative to ASHRAE 90.1-2007, ranging from -4.9 % to -28.5 % depending on the 

building type with an overall average of -15.0 %. 

Table 15-2 Average Percentage Change in Energy Use from Adoption of a Newer 

Standard Edition, 10-Year, Oregon 

Building LEC 

Type Energy Use Energy Cost Carbon LCC 

APART04 -10.0 -15.0 -15.4 1.1 

APART06 -10.9 -17.1 -17.7 1.0 

DORMI04 -12.7 -16.7 -17.0 -1.0 

DORMI06 -10.6 -16.7 -17.1 0.7 

HOTEL15 -13.8 -18.4 -18.8 0.9 

HIGHS02 -4.9 -11.5 -12.1 -0.0 

OFFIC03 -21.2 -23.5 -23.6 -3.5 

OFFIC08 -20.9 -22.0 -22.0 -3.0 

OFFIC16 -17.8 -20.9 -21.1 1.0 

RETAIL1 -13.2 -15.3 -15.4 0.8 

RSTRNT1 -28.5 -33.0 -33.4 -4.5 

Average -15.0 -19.1 -19.4 -0.6 

There is a significant variation in the average percentage change in energy costs for the 

LEC design, ranging from -11.5 % to -33.0 % depending on the building type, with an 

average of -19.1 % for 10 years of building operation. The energy costs are reduced by a 

greater percentage than energy use because the energy efficiency measures decrease 

electricity consumption by a greater percentage than natural gas consumption. In fact, for 

all 11 building types the energy efficiency measures increase natural gas consumption 

while decreasing electricity consumption. The shift is most prevalent for the high school, 

where the increase in natural gas consumption offsets 59.9 % of the reduction in 

electricity consumption, and results in a percentage reduction in energy costs that is over 

two times greater than the percentage reduction in energy use. The LEC design 

incorporates daylighting and overhangs into the building design for cities in Zone 4 and 

Zone 5, which decreases the building’s internal and external heat gains, respectively. The 

shift in energy use from electricity to natural gas consumption to meet the greater heating 

loads decreases energy costs because natural gas is cheaper on a per unit of energy basis 

relative to electricity. 

There is significant variation in the average percentage change in energy-related carbon 

emissions for the LEC design across building types, ranging from -12.1 % to -33.4 % 

with an average of -19.4 %. As mentioned above, the energy efficiency measures 

decrease electricity consumption while increasing natural gas consumption for all 11 

building types. The combination of the reduction in total energy use and the shift in 

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Oregon 

energy use from electricity consumption to natural gas consumption leads to greater 

reductions in carbon emissions than reductions in energy use. 

The LEC design results in significant variations in life-cycle costs across building types. 

Of the 11 building types, 5 realize a reduction in life-cycle costs for a 10-year study 

period. The percentage change in life-cycle costs for the LEC design ranges from -4.5 % 

to 1.1 %. Based on the overall average change of -0.6 % in life-cycle costs, the LEC 

design may be cost-effective if the state adopted it as its state energy code for commercial 

buildings. 

15.1.2 City Comparisons 

Simulations are run for 9 cities located in Oregon: Astoria, Eugene, Medford, North 

Bend, Portland, and Salem in Climate Zone 4C and Burns, Pendleton, and Redmond in 

Climate Zone 5B. The results vary across cities within the state for several reasons. First, 

the state is covered by two climate zones. The LEC design requirements vary across 

climate zones and will impact the relative energy efficiency of the building. Second, 

cities within the same climate zone still have some variation in the local climate, which 

can lead to variation in energy consumption. Third, construction material and labor costs 

vary by locality. 

Table 15-3 shows the percentage change in energy use, energy costs, energy-related 

carbon emissions, and life-cycle costs for the LEC design relative to ASHRAE 90.1-2007 

for each city in the state. 

Table 15-3 Average Percentage Change in Energy Use from Adoption of Newer 

Standard Editions by City, 10-Year, Oregon 

Cities Zone LEC 

Energy Use Energy Cost Carbon LCC 

Astoria 4C -14.2 -18.5 -18.8 -0.5 

Eugene 4C -15.6 -19.6 -20.0 -0.7 

Medford 4C -15.6 -19.6 -20.0 -0.9 

North Bend 4C -16.2 -20.6 -20.8 -0.3 

Portland 4C -16.0 -19.7 -20.0 -0.2 

Salem 4C -15.3 -19.3 -19.7 -0.7 

Burns 5B -12.9 -17.4 -17.8 -0.8 

Pendleton 5B -15.1 -19.0 -19.5 -0.9 

Redmond 5B -13.7 -18.2 -18.7 -0.6 

Average -15.0 -19.1 -19.5 -0.6 

The average percentage change in energy use for all building types from adopting the 

LEC design varies across cities from -12.9 % to -16.2 %. Cities in Zone 4C realize 

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Oregon 

slightly greater reductions in energy use relative to Zone 5B. The average change in 

energy costs for all building types varies across cities, from -17.4 % to -20.6 %, with 

Zone 4C realizing a slightly larger change than Zone 5B for 10 years of building 

operation. For all cities, the LEC design results in percentage changes in carbon 

emissions ranging from -17.8 % to -20.8 % with an overall average of -19.5 %. 

Reductions in energy costs and carbon emissions are larger than the reductions in energy 

use because electricity consumption decreases while natural gas consumption increases. 

Adoption of the LEC design results in average percentage reductions in life-cycle costs 

for all cities for a 10-year study period, ranging from -0.2 % to -0.9 %. 

15.2 Total Savings 

How much can Oregon save, in terms of energy use, energy costs, and carbon emissions, 

from adopting a more stringent state energy code for commercial buildings? What are the 

life-cycle costs associated with the new energy code adoption? To answer these 

questions, it is necessary to estimate savings per unit of floor area for each building type 

in the state. 

15.2.1 Energy Use 

Table 15-4 reports the average per unit change in annual energy use by building type in 

the state.34 The reduction per m2 (ft2

) is multiplied by the estimated m2 (ft2) of new 

construction of each building type, and Table 15-5 reports the estimated average annual 

floor area of new construction and the total annual reduction in energy use for each 

building type. The weightings within a category (e.g., small, medium, and large office 

buildings) are based on the national average percentage of new building construction for 

the category that is represented by each subcategory.35 

34 A simple average for a state is used because no data for a weighted average is available regarding the
 

amount of new construction on a city-by-city basis.
 

35 State-level subcategory data are not available.
 

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Oregon 

Table 15-4 Average Per Unit Change in Annual Energy Use, Oregon
 

Building Standard Edition 

Type LEC 

kWh/m2 kBtu/ft2 

APART04 -12.4 -3.9 

APART06 -13.6 -4.3 

DORMI04 -12.0 -3.8 

DORMI06 -14.4 -4.6 

HOTEL15 -18.2 -5.8 

HIGHS02 -20.2 -6.4 

OFFIC03 -9.3 -2.9 

OFFIC08 -19.1 -6.0 

OFFIC16 -23.4 -7.4 

RETAIL1 -13.6 -4.3 

RSTRNT1 -40.3 -12.8 

The LEC design decreases overall energy use across the state. The adoption of the LEC 

design as the state’s energy code saves energy for all building types and 13.9 GWh (47.4 

GBtu) of total energy use annually for one year’s worth of new construction for these 

building types. Assuming that the buildings considered in this study, which represent 

53.1 % of all new commercial floor space in the state, are generally representative of the 

entire new commercial building stock in the state, the results can be extrapolated to 

estimate the total statewide savings to be 26.1 GWh (89.2 GBtu) in energy savings per 

year. These savings imply 261.4 GWh (892.4 GBtu) in energy savings over the 10-year 

study period. 

Table 15-5 Statewide Change in Annual Energy Use for One Year of Construction, 

Oregon 

Building Subcategory m 2 ft2 Standard Edition 

Type Weighting (1000s) (1000s) LEC 

kWh kBtu 

APART04 44.9 % 113 1213 -1 394 046 -4 759 872
 

APART06 55.1 % 138 1486 -1 871 932 -6 391 581
 

HOTEL15 100.0 % 72 776 -1 314 161 -4 487 110 

HIGHS02 100.0 % 130 1401 -1 208 058 -4 124 830 

OFFIC03 37.4 % 69 743 -1 397 542 -4 771 808 

OFFIC08 40.4 % 74 801 -1 418 430 -4 843 130 

OFFIC16 22.2 % 41 441 -957 706 -3 270 019 

RETAIL1 100.0 % 276 2976 -3 771 343 -12 876 986 

RSTRNT1 100.0 % 14 146 -544 826 -1 860 269 

Total 927 9982 -13 878 043 -47 385 606 

Note: Dormitories are excluded because no such floor area category is reported 

in the construction data. 

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Oregon 

The statewide change in total energy use varies across building types. Building types that 

represent a greater amount of new floor area realize the largest changes in energy use. 

The building types that have the greatest percentage reduction in energy use are not 

always the same buildings that lead to the greatest total reductions for the state. For 

example, the building types that lead to the greatest estimated reductions in energy use 

for the LEC design -- retail stores and 6-story apartment buildings -- only rank 6th and 8th 

in percentage reduction, respectively, among the 11 building types, as reported in Table 

15-2. 

15.2.2 Energy Costs 

Table 15-6 reports the average per unit change in energy costs by building type. Energy 

costs are calculated using the annual energy use, state average energy cost rates, and 

regional energy price escalation rates as defined in Section 3.2. 

Table 15-6 Average Per Unit Change in Energy Costs, 10-Year, Oregon 

Building Standard Edition 

Type LEC 

$/m2 $/ft2 

APART04 -$8.38 -$0.78 

APART06 -$9.70 -$0.90 

DORMI03 -$7.51 -$0.70 

DORMI06 -$10.26 -$0.95 

HOTEL15 -$11.33 -$1.05 

HIGHS02 -$9.48 -$0.88 

OFFIC03 -$12.39 -$1.15 

OFFIC08 -$11.44 -$1.06 

OFFIC16 -$14.61 -$1.36 

RETAIL1 -$8.25 -$0.77 

RSTRNT1 -$24.09 -$2.24 

Table 15-7 reports the statewide changes in total energy costs by building type and 

building design, which account for one year’s worth of new construction evaluated over 

10 years of building operation. The LEC design leads to statewide reductions in energy 

costs of $9.2 million. All building types realize energy cost savings, ranging from 

$325 917 to $2.3 million. The total reductions in energy costs are correlated with total 

reductions in energy use, but there is some variation due to the variation in the energy 

source of the reductions. 

Assuming that the buildings considered in this study, which represent 53.1 % of all new 

commercial floor space in the state, are generally representative of the entire new 

commercial building stock in the state, the results for the LEC design can be extrapolated 

140
 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Oregon 

to estimate the total statewide energy cost savings of $17.4 million over the 10-year study 

period. 

Table 15-7 Statewide Change in Energy Costs for One Year of Construction, 

10-Year, Oregon 

Building Subcategory m 2 ft2 Standard Edition 

Type Weighting (1000s) (1000s) LEC 

APART04 44.9 % 113 1213 -$944 794 

APART06 55.1 % 138 1486 -$1 338 087 

HOTEL15 100.0 % 72 776 -$816 090 

HIGHS02 67.5 % 130 1401 -$1 233 331 

OFFIC03 37.4 % 69 743 -$855 651 

OFFIC08 40.4 % 74 801 -$851 595 

OFFIC16 22.2 % 41 441 -$598 644 

RETAIL1 100.0 % 276 2976 -$2 281 802 

RSTRNT1 100.0 % 14 146 -$325 917 

Total 927 9982 -$9 245 909 

Note: Dormitories are excluded because no such floor area category 

is reported in the construction data. 

15.2.3 Energy-related Carbon Emissions 

Table 15-8 reports the average reduction in energy-related carbon emissions over 10 

years, per m 

2 (ft2

), by building type and building design. The carbon emissions estimation 

approach is defined in Section 5.3. 

Table 15-8 Average Per Unit Change in Carbon Emissions, 10-Year, Oregon 

Building Standard Edition 

Type LEC 

kg/m2 lb/ft2 

APART04 -70.4 -14.4 

APART06 -81.7 -16.7 

DORMI04 -62.8 -12.9 

DORMI06 -86.4 -17.7 

HOTEL15 -94.7 -19.4 

HIGHS02 -81.0 -16.6 

OFFIC03 -103.5 -21.2 

OFFIC08 -95.4 -19.5 

OFFIC16 -122.2 -25.0 

RETAIL1 -68.9 -14.1 

RSTRNT1 -201.0 -41.2 

Table 15-9 applies the Table 15-8 results to one year’s worth of new building 

construction in the state to estimate statewide total reduction in carbon emissions from 

141 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Oregon 

adoption of a more energy efficient code. Adoption of the LEC design as the state’s 

energy code decreases carbon emissions by 77 601 metric tons over the 10-year study 

period for one year’s worth of new commercial construction for these building types. 

Assuming that the buildings considered in this study are generally representative of the 

entire new commercial building stock in the state, the results for the LEC design can be 

extrapolated to estimate the total statewide reduction in carbon emissions of 

146 141 metric tons over the 10-year study period. The total reduction in carbon 

emissions for each building type is correlated with its total reduction in energy use. 

Table 15-9 Statewide Change in Total Carbon Emissions for One Year of 

Construction, 10-Year, Oregon – Metric Tons 

Building Subcategory m 2 ft2 Standard Edition
 

Type Weighting (1000s) (1000s) LEC
 

APART04 44.9 % 113 1213 -7 937
 

APART06 55.1 % 138 1486 -11 272
 

HOTEL15 100.0 % 72 776 -6823 

HIGHS02 67.5 % 130 1401 -10 544 

OFFIC03 37.4 % 69 743 -7148 

OFFIC08 40.4 % 74 801 -7105 

OFFIC16 22.2 % 41 441 -5007 

RETAIL1 100.0 % 276 2976 -19 047 

RSTRNT1 100.0 % 14 146 -2719 

Total 927 9982 -77 601 

Note: Dormitories are excluded because no such floor area category is 

reported in the construction data. 

15.2.4 Life-Cycle Costs 

Table 15-10 reports the average change in life-cycle cost over 10 years, per m2 (ft2), by 

building type. As discussed in Section 5.2, life-cycle costs include construction costs, 

maintenance, repair, and replacement costs, energy costs, and residual values. 

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reported in the construction data .

Oregon 

Table 15-10 Average Per Unit Change in Life-Cycle Costs, 10-Year, Oregon
 

Building Standard Edition 

Type LEC 

$/m2 $/ft2 

APART04 $10.86 $1.01 

APART06 $9.96 $0.93 

DORMI04 -$9.75 -$0.91 

DORMI06 $7.11 $0.66 

HOTEL15 $8.64 $0.80 

HIGHS02 -$0.13 -$0.01 

OFFIC03 -$28.91 -$2.69 

OFFIC08 -$26.16 -$2.43 

OFFIC16 $8.19 $0.76 

RETAIL1 $5.27 $0.49 

RSTRNT1 -$62.04 -$5.76 

Table 15-11 applies the Table 15-10 results to one year’s worth of new building 

construction in the state to estimate the change in statewide life-cycle costs from adoption 

of a more energy-efficient code. The LEC design leads to an increase in statewide lifecycle costs of $213 782 and increases life-cycle costs for 5 of 9 building types. Retail 

stores and hotels account for a $2.1 million ($1.5 million and $622 209, respectively) 

increase in life-cycle costs. 

Assuming that the buildings considered in this study are generally representative of the 

entire new building stock in the state, the results for the LEC design can be extrapolated 

to estimate the increase in total statewide life-cycle costs of $402 602 over the 10-year 

study period. 

Table 15-11 Statewide Change in Life-Cycle Costs for One Year of Construction, 

10-Year, Oregon 

Building Subcategory m 2 ft2 Standard Edition
 

Type Weighting (1000s) (1000s) LEC
 

APART04 44.9 % 113 1213 $1 223 170
 

APART06 55.1 % 138 1486 $1 374 597
 

HOTEL15 100.0 % 72 776 $622 209 

HIGHS02 100.0 % 130 1401 -$17 512 

OFFIC03 37.4 % 69 743 -$1 995 630 

OFFIC08 40.4 % 74 801 -$1 947 568 

OFFIC16 22.2 % 41 441 $335 656 

RETAIL1 100.0 % 276 2976 $1 458 084 

RSTRNT1 100.0 % 14 146 -$839 223 

Total 927 9982 $213 782 

Note: Dormitories are excluded because no such floor area category is 

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Oregon 

15.3 State Summary 

Oregon has adopted ASHRAE 90.1-2007 as its state commercial building energy code. On 

average, adopting the LEC design reduces energy use, energy costs, and energy-related 

carbon emissions, but does not do so in a cost-effective manner. Based on the average 

annual new commercial construction in the state from 2003 to 2007 and a 10-year study 

period, adopting the LEC design as the state’s energy code would lead to statewide 

energy savings of 261.4 GWh (892.4 GBtu), energy cost savings of $17.4 million, and 

carbon emissions reductions of 146 141 metric tons at a life-cycle cost of $402 602 for 

one year’s worth of commercial building construction. Oregon is one of two states in this 

report that realize an increase in life-cycle costs from adopting the LEC design. 

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Utah 

16 Utah 

Utah has adopted ASHRAE 90.1-2007 as its state energy code for commercial buildings, 

is located in the Mountain Census Division, and spans three climate zones (Zone 3B, 

Zone 5B, and Zone 6B). Table 16-1 provides an overview of Utah’s simulated energy use 

keyed to building types and energy codes. Average energy use varies across building 

types and building designs. The 8-story office building uses the least amount of energy at 

78 kWh/m2 to 98 kWh/m2 (25 kBtu/ft2 to 31 kBtu/ft2

) annually. The high school uses the 

greatest amount of energy at 188 kWh/m2 to 199 kWh/m2 (60 kBtu/ft2 to 63 kBtu/ft2) 

annually. 

Table 16-1 Average Annual Energy Use by Building Type and Standard Edition, 

Utah 

Building 

Type 

Standard Edition 

2007 

kWh/m2 kBtu/ft2 

LEC 

kWh/m2 kBtu/ft2 

APART04 

APART06 

134 42 

132 42 

119 38 

116 37 

DORMI04 

DORMI06 

104 33 

147 47 

90 29 

130 41 

HOTEL15 142 45 122 39 

HIGHS02 199 63 188 60 

OFFIC03 

OFFIC08 

OFFIC16 

104 33 

98 31 

143 45 

82 26 

78 25 

118 37 

RETAIL1 112 36 98 31 

RSTRNT1 155 49 113 36 

The detailed analysis for this state reports the changes in energy use, energy costs, 

energy-related carbon emissions, and life-cycle costs from adoption of the LEC design. 

The results are reported in terms of average percentage savings on a statewide and 

city-by-city basis and as total savings on a statewide basis. 

16.1 Percentage Savings 

Changes in percentage terms allow for direct comparisons across building types and 

locations within a state. This section discusses the average percentage changes from 

investing in the LEC design in the state of Utah. 

16.1.1 Statewide Building Comparison 

Table 16-2 shows the percentage change in energy use, energy costs, energy-related 

carbon emissions, and life-cycle costs for the LEC design relative to ASHRAE 90.1-2007. 

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Utah 

There is significant variation in the change in energy use for the LEC design relative to 

ASHRAE 90.1-2007, ranging from -5.9 % to -27.1 % depending on the building type with 

an overall average of -15.1 %. High schools realize the lowest reduction in energy use 

while restaurants realize the greatest reduction in energy use. 

Table 16-2 Average Percentage Change from Adoption of Newer Standard 

Editions, 10-Year, Utah 

Building LEC 

Type Energy Use Energy Cost Carbon LCC 

APART04 -10.7 -17.6 -15.7 0.7 

APART06 -11.9 -20.5 -18.2 0.6 

DORMI04 -12.8 -18.2 -16.8 -1.2 

DORMI06 -12.0 -20.1 -18.0 0.3 

HOTEL15 -14.2 -20.2 -18.6 0.6 

HIGHS02 -5.9 -15.6 -12.8 -0.8 

OFFIC03 -20.8 -24.6 -23.7 -3.0 

OFFIC08 -20.7 -22.5 -22.1 -2.6 

OFFIC16 -17.5 -21.7 -20.8 0.6 

RETAIL1 -13.0 -17.3 -16.3 1.2 

RSTRNT1 -27.1 -34.7 -32.9 -3.8 

Average -15.1 -21.2 -19.6 -0.7 

There is a significant variation in the average percentage change in energy costs for the 

LEC design relative to ASHRAE 90.1-2007, ranging from -15.6 % to -34.7 % depending 

on the building type with an average of -21.2 % for 10 years of building operation. The 

energy costs are reduced by a greater percentage than energy use because the energy 

efficiency measures decrease electricity consumption by a greater percentage than natural 

gas consumption. In fact, adopting the LEC design leads to an increase in natural gas 

consumption and a decrease in electricity consumption for all 11 building types. The shift 

is most prevalent for the high school, where the increase in natural gas consumption 

offsets 52.3 % of the reduction in electricity consumption, and results in a percentage 

reduction in energy costs that is 2.6 times the percentage reduction in energy use. The 

LEC design incorporates daylighting and overhangs into the building design for cities in 

Zone 3 and Zone 5, which decreases the building’s internal and external heat gains, 

respectively. The shift in energy use from electricity to natural gas consumption to meet 

the greater heating loads decreases energy costs because natural gas is cheaper on a per 

unit of energy basis relative to electricity. 

There is significant variation in the average change in energy-related carbon emissions 

across building types for the LEC design relative to ASHRAE 90.1-2007, ranging 

from -12.8 % to -32.9 % with an average of -19.6 %. As mentioned above, the energy 

efficiency measures decrease electricity consumption while increasing natural gas 

consumption for all 11 building types. The combination of the reduction in total energy 

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Utah 

use and the shift in energy use from electricity consumption to natural gas consumption 

leads to greater reductions in carbon emissions than reductions in energy use. 

The percentage change in life-cycle costs varies across building types, ranging 

from -3.8 % to 1.2 % for a 10-year study period. Five of the 11 building types realize 

reductions in life-cycle costs. Based on the overall average percentage change of -0.7 % 

in life-cycle costs, the LEC design may be cost-effective if the state adopted it as its state 

energy code for commercial buildings. 

16.1.2 City Comparisons 

Simulations are run for two cities located in Utah, both of which are located in Zone 5B: 

Cedar City and Salt Lake City. Utah has no significant population centers located in Zone 

3B or Zone 6B. While the two cities are located in the same climate zone, the results may 

still vary for two reasons. First, cities within the same climate zone may have some 

variation in the local climate, which can lead to variation in energy consumption. Second, 

construction material and labor costs may vary significantly by locality. 

Table 16-3 shows the percentage change in energy use, energy costs, energy-related 

carbon emissions, and life-cycle costs for the LEC design relative to ASHRAE 90.1-2007 

for each city in the state. The average percentage change in energy use for all building 

types from adopting the LEC design varies minimally between cities, ranging from ­

14.9 % to -15.4 %. Any variation in local climate appears to have minimal effects on 

energy consumption. 

Table 16-3 Average Percentage Change from Adoption of Newer Standard Editions 

by City, 10-Year, Utah 

Cities Zone LEC 

Energy Use Energy Cost Carbon LCC 

Cedar City 5B -14.9 -21.2 -19.7 -0.7 

Salt Lake City 5B -15.4 -21.2 -19.8 -0.6 

Average -15.1 -21.2 -19.7 -0.7 

The average percentage change in energy costs for all building types does not vary 

between cities (-21.2 %) for 10 years of operation. The average percentage change in 

carbon emissions for all building types varies minimally, with a difference of 

0.1 percentage point. For both cities, reductions in energy costs and carbon emissions are 

greater than reductions in energy use because of the shift from electricity to natural gas 

consumption. The percentage change in life-cycle costs for all building types only varies 

by 0.1 percentage point. 

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Utah 

16.2 Total Savings 

How much can Utah save, in terms of energy use, energy costs, and carbon emissions, 

from adopting a more stringent state energy code for commercial buildings? What are the 

life-cycle costs associated with the new energy code adoption? To answer these 

questions, it is necessary to estimate savings per unit of floor area for each building type 

in the state. 

16.2.1 Energy Use 

Table 16-4 reports the average per unit change in annual energy use by building type and 

building design in the state.36 The reduction per m2 (ft2

) is multiplied by the estimated m2 

(ft2) of new construction of each building type, and Table 16-5 reports the estimated 

average annual floor area of new construction and the total annual reduction in energy 

use for each building type. The weightings within a category (e.g., small, medium, and 

large office buildings) are based on the national average percentage of new building 

construction for the category that is represented by each subcategory.37 

Table 16-4 Average Per Unit Change in Annual Energy Use, Utah 

Building Standard Edition 

Type LEC 

kWh/m2 kBtu/ft2 

APART04 -14.3 -4.5 

APART06 -15.7 -5.0 

DORMI04 -13.3 -4.2 

DORMI06 -17.7 -5.6 

HOTEL15 -20.1 -6.4 

HIGHS02 -21.5 -6.8 

OFFIC03 -11.8 -3.8 

OFFIC08 -20.3 -6.4 

OFFIC16 -25.1 -8.0 

RETAIL1 -14.6 -4.6 

RSTRNT1 -42.1 -13.3 

The adoption of the LEC design as the state’s energy code for commercial buildings 

would save energy for all building types and 16.9 GWh (57.7 GBtu) of total energy use 

annually for one year’s worth of new construction for these building types. Assuming that 

the buildings considered in this study, which represent 59.0 % of all new commercial 

floor space in the state, are generally representative of the entire new commercial 

building stock in the state, the results can be extrapolated to estimate statewide savings to 

36 A simple average for a state is used because no data for a weighted average is available regarding the
 

amount of new construction on a city-by-city basis.
 

37 State-level subcategory data are not available.
 

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Utah 

be 28.7 GWh (97.8 GBtu) per year. These savings imply 286.6 GWh (978.5 GBtu) in 

energy use savings over the 10-year study period. 

The change in energy use varies across building types. The building types that have the 

greatest percentage reductions are not always the same buildings that lead to the greatest 

total reductions for the state. Instead the building types that represent a greater amount of 

new floor area realize the largest changes in energy use. The greatest total reductions are 

realized by retail stores and high schools because they represent 28.1 % and 25.0 %, 

respectively, of the combined new construction in the state for the building types in this 

study while all other building types represent 10.9 % or less. The amount of new 

construction overwhelms the relative percentage changes in energy use. The building 

types that lead to the greatest estimated reductions in energy use for the LEC design -­

retail stores and high schools -- only rank 6th and 11th in percentage reduction, 

respectively, among the 11 building types, as reported in Table 16-2. 

Table 16-5 Statewide Change in Annual Energy Use for One Year of Construction, 

Utah 

Building Subcategory m 2 ft2 Standard Edition 

Type Weighting (1000s) (1000s) LEC 

kWh kBtu 

APART04 44.9 % 56 602 -801 445 -2 736 477 

APART06 55.1 % 68 737 -1 078 497 -3 682 451 

HOTEL15 100.0 % 63 677 -1 266 599 -4 324 712 

HIGHS02 100.0 % 254 2731 -3 004 218 -10 257 691 

OFFIC03 37.4 % 102 1100 -2 198 593 -7 506 942 

OFFIC08 40.4 % 110 1187 -2 234 967 -7 631 137 

OFFIC16 22.2 % 61 653 -1 520 873 -5 192 914 

RETAIL1 100.0 % 285 3066 -4 160 002 -14 204 037 

RSTRNT1 100.0 % 15 164 -642 556 -2 193 962 

Total 1014 10 917 -16 907 748 -57 730 322 

Note: Dormitories are excluded because no such floor area category is reported 

in the construction data. 

16.2.2 Energy Costs 

Table 16-6 reports the average per unit change in energy costs by building type for the 

LEC design. Energy costs are calculated using the annual energy use, state average 

energy cost rates, and regional energy price escalation rates as defined in Section 3.2. 

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Utah 

Table 16-6 Average Per Unit Change in Energy Costs, 10-Year, Utah
 

Building Standard Edition 

Type LEC 

$/m2 $/ft2 

APART04 -$9.01 -$0.84 

APART06 -$10.55 -$0.98 

DORMI04 -$7.70 -$0.72 

DORMI06 -$11.55 -$1.07 

HOTEL15 -$11.45 -$1.06 

HIGHS02 -$12.62 -$1.17 

OFFIC03 -$11.13 -$1.03 

OFFIC08 -$11.48 -$1.07 

OFFIC16 -$14.72 -$1.37 

RETAIL1 -$8.81 -$0.82 

RSTRNT1 -$24.33 -$2.26 

Table 16-7 reports the statewide changes in total energy costs by building type and 

building design, which account for one year’s worth of new construction evaluated over 

10 years. All building types realize energy cost savings for the LEC design, with a 

statewide reduction in energy costs of $11.1 million for 10 years of building operation. 

Assuming that the buildings considered in this study, which represent 59.0 % of all new 

commercial floor space in the state, are generally representative of the entire new 

commercial building stock in the state, the results for the LEC design can be extrapolated 

to estimate total statewide energy cost savings of $18.8 million over the 10-year study 

period. 

Table 16-7 Statewide Change in Energy Costs for One Year of Construction, 

10-Year, Utah 

Building Subcategory m 2 ft2 Standard Edition
 

Type Weighting (1000s) (1000s)
 LEC 

APART04 44.9 % 56 602 -$503 505 

APART06 55.1 % 68 737 -$722 168 

HOTEL15 100.0 % 63 677 -$719 951 

HIGHS02 100.0 % 254 2731 -$2 824 295 

OFFIC03 37.4 % 102 1100 -$1 289 985 

OFFIC08 40.4 % 110 1187 -$1 265 313 

OFFIC16 22.2 % 61 653 -$893 037 

RETAIL1 100.0 % 285 3066 -$2 508 674 

RSTRNT1 100.0 % 15 164 -$371 550 

Total 1014 10 917 -$11 098 478 

Note: Dormitories are excluded because no such floor area category 

is reported in the construction data. 

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Utah 

16.2.3 Energy-related Carbon Emissions 

Table 16-8 reports the average reduction in energy-related carbon emissions over 10 

years, per m 2 (ft2

), by building type. The carbon emissions estimation approach is defined 

in Section 5.3. 

Table 16-8 Average Per Unit Change in Carbon Emissions, 10-Year, Utah 

Building Standard Edition 

Type LEC 

kg/m2 lb/ft2 

APART04 -78.7 -16.1 

APART06 -91.2 -18.7 

DORMI04 -68.4 -14.0 

DORMI06 -100.3 -20.5 

HOTEL15 -102.1 -20.9 

HIGHS02 -91.4 -18.7 

OFFIC03 -111.8 -22.9 

OFFIC08 -102.4 -21.0 

OFFIC16 -130.4 -26.7 

RETAIL1 -77.6 -15.9 

RSTRNT1 -216.1 -44.3 

Table 16-9 applies the Table 16-8 results to one year’s worth of new building 

construction in the state to estimate the statewide reduction in carbon emissions from 

adoption of the LEC design. The total reduction in carbon emissions ranges widely across 

building designs, and is highly correlated with the total reduction in energy use. The LEC 

design decreases carbon emissions for all building types. The adoption of the LEC design 

results in savings of 96 278 metric tons over the 10-year study period for one year’s 

worth of new commercial construction for these building types. Assuming that the 

buildings considered in this study are generally representative of the entire new 

commercial building stock in the state, the results for the LEC design can be extrapolated 

to estimate the statewide reduction in carbon emissions of 144 345 metric tons over the 

10-year study period. 

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Utah 

Table 16-9 Statewide Change in Total Carbon Emissions for One Year of 

Construction, 10-Year, Utah – Metric Tons 

Building Subcategory m 2 ft2 Standard Edition
 

Type Weighting (1000s) (1000s)
 LEC 

APART04 44.9 % 56 602 -4403 

APART06 55.1 % 68 737 -6243 

HOTEL15 100.0 % 63 677 -6418 

HIGHS02 100.0 % 254 2731 -23 184 

OFFIC03 37.4 % 102 1100 -11 427 

OFFIC08 40.4 % 110 1187 -11 288 

OFFIC16 22.2 % 61 653 -7910 

RETAIL1 100.0 % 285 3066 -22 105 

RSTRNT1 100.0 % 15 164 -3301 

Total 1014 10 917 -96 278 

Note: Dormitories are excluded because no such floor area category 

is reported in the construction data. 

16.2.4 Life-Cycle Costs 

Table 16-10 reports the average change in life-cycle cost over 10 years, per m2 (ft2

), by 

building type. As discussed in Section 5.2, life-cycle costs include construction costs, 

maintenance, repair, and replacement costs, energy costs, and residual values. 

Table 16-10 Average Per Unit Change in Life-Cycle Costs, 10-Year, Utah 

Building Standard Edition 

Type LEC 

$/m2 $/ft2 

APART04 $5.81 $0.54 

APART06 $5.14 $0.48 

DORMI04 -$9.82 -$0.91 

DORMI06 $2.49 $0.23 

HOTEL15 $5.02 $0.47 

HIGHS02 -$5.47 -$0.51 

OFFIC03 -$20.86 -$1.94 

OFFIC08 -$18.89 -$1.75 

OFFIC16 $4.34 $0.40 

RETAIL1 $6.47 $0.60 

RSTRNT1 -$42.98 -$3.99 

Table 16-11 applies the Table 16-10 results to one year’s worth of new building 

construction in the state to estimate statewide changes in life-cycle costs from adoption of 

the LEC design. Total changes in life-cycle costs over the 10-year study period vary 

across building type, with 4 of 9 building types realizing reductions in life-cycle costs. 

Overall, the LEC design results in a decrease of $3.2 million in statewide life-cycle costs 

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Utah 

relative to ASHRAE 90.1-2007. Three-story and 8-story office buildings realize the 

greatest reduction in life-cycle costs (both at $2.1 million). Retail stores realize the 

greatest increase in life-cycle costs ($1.8 million). Assuming that the buildings 

considered in this study are generally representative of the entire new commercial 

building stock in the state, the results for the LEC design can be extrapolated to estimate 

a statewide decrease in life-cycle costs of $5.4 million over the 10-year study period. 

Table 16-11 Statewide Change in Life-Cycle Costs for One Year of Construction, 

10-Year, Utah 

Building Subcategory m 2 ft2 Standard Edition 

Type Weighting (1000s) (1000s) LEC 

APART04 44.9 % 56 602 $324 756
 

APART06 55.1 % 68 737 $352 146
 

HOTEL15 100.0 % 63 677 $315 489 

HIGHS02 100.0 % 254 2731 -$1 387 265 

OFFIC03 37.4 % 102 1100 -$2 132 105 

OFFIC08 40.4 % 110 1187 -$2 081 708 

OFFIC16 22.2 % 61 653 $263 132 

RETAIL1 100.0 % 285 3066 $1 843 106 

RSTRNT1 100.0 % 15 164 -$656 404 

Total 1014 10 917 -$3 158 854 

Note: Dormitories are excluded because no such floor area category 

is reported in the construction data. 

16.3 State Summary 

Utah has adopted ASHRAE 90.1-2007 as its state energy code for commercial buildings. 

On average, adopting the LEC design reduces energy use, energy costs, and energyrelated carbon emissions, and does so in a life-cycle cost-effective manner. Based on the 

average annual new construction in the state from 2003 to 2007 and a 10-year study 

period, adopting the LEC design as the state’s energy code for commercial buildings 

would lead to statewide energy use savings of 286.6 GWh (978.5 GBtu), energy cost 

savings of $18.8 million, and carbon emissions reductions of 144 345 metric tons while 

decreasing life-cycle costs of $5.4 million for one year’s worth of commercial building 

construction. 

153
 
Utah 

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Washington 

17 Washington 

Washington has adopted ASHRAE 90.1-2007 as its state energy code for commercial 

buildings, is located in the Pacific Census Division, and spans three climate zones 

(Zone 4C, Zone 5B, and Zone 6B). Table 17-1 provides an overview of Washington’s 

simulated energy use keyed to building types and energy standard editions. Average 

energy use varies across building types and building designs. The 8-story office building 

uses the least amount of energy at 73 kWh/m2 to 91 kWh/m2 (23 kBtu/ft2 to 29 kBtu/ft2

) 

annually. The high school uses the greatest amount of energy at 197 kWh/m2 to 206 

kWh/m2 (63 kBtu/ft2 to 65 kBtu/ ft2

) annually. 

Table 17-1 Average Annual Energy Use by Building Type and Standard Edition, 

Washington 

Building 

Type 

Standard Edition 

2007 

kWh/m2 kBtu/ft2 

LEC 

kWh/m2 kBtu/ft2 

APART04 

APART06 

134 42 

134 42 

122 39 

121 38 

DORMI04 

DORMI06 

105 33 

146 46 

93 29 

132 42 

HOTEL15 144 46 126 40 

HIGHS02 206 65 197 63 

OFFIC03 

OFFIC08 

OFFIC16 

98 31 

91 29 

138 44 

79 25 

73 23 

115 37 

RETAIL1 107 34 94 30 

RSTRNT1 147 47 108 34 

The detailed analysis for this state reports changes in energy use, energy costs, 

energy-related carbon emissions, and life-cycle costs from adoption of the LEC design 

beyond the current state energy code. The results are reported in terms of average 

percentage savings on a statewide and city-by-city basis and as total savings on a 

statewide basis. 

17.1 Percentage Savings 

Changes in percentage terms allow for direct comparisons across building types and 

locations within a state. This section discusses the average percentage changes from 

investing in the LEC design for the state of Washington. 

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Washington 

17.1.1 Statewide Building Comparison 

Table 17-2 shows the percentage change in energy use, energy costs, energy-related 

carbon emissions, and life-cycle costs for the LEC design relative to ASHRAE 90.1-2007. 

The LEC design realizes changes in energy use ranging from -4.2 % to -26.4 %, with an 

average of -13.6 %. The lowest reduction in energy use for the LEC design occurs in the 

high school while the greatest reduction in energy use occurs in restaurants. 

Table 17-2 Average Percentage Change from Adoption of a Newer Standard 

Edition, 10-Year, Washington 

Building LEC 

Type Energy Use Energy Costs Carbon LCC 

APART04 -8.8 -12.8 -14.0 1.2 

APART06 -9.4 -14.4 -15.8 1.2 

DORMI04 -11.6 -15.0 -16.0 -0.5 

DORMI06 -9.2 -14.1 -15.5 0.9 

HOTEL15 -12.3 -16.2 -17.2 1.1 

HIGHS02 -4.2 -9.4 -10.9 0.2 

OFFIC03 -19.6 -21.9 -22.4 -2.7 

OFFIC08 -20.0 -21.1 -21.3 -2.3 

OFFIC16 -16.2 -19.1 -19.8 1.4 

RETAIL1 -12.3 -13.9 -14.3 1.1 

RSTRNT1 -26.4 -30.6 -31.6 -3.9 

Average -13.6 -17.1 -18.1 -0.2 

The LEC design realizes average percentage changes in energy costs over 10 years of 

building operation ranging from -9.4 % to -30.6 % depending on the building type, with 

an average of -17.1 % overall. The energy costs are reduced by a greater percentage than 

energy use because the energy efficiency measures decrease electricity consumption by a 

greater percentage than natural gas consumption. For 10 of the 11 building types, the 

energy efficiency measures increase natural gas consumption while decreasing electricity 

consumption. The shift is most prevalent for the high school, where the increase in 

natural gas consumption offsets 60.8 % of the reduction in electricity consumption, and 

results in a percentage reduction in energy costs that is over twice the percentage 

reduction in energy use. The LEC design incorporates daylighting into the building 

design for all climate zones and overhangs for cities in Zone 4 and Zone 5, which 

decreases the building’s internal and external heat gains, respectively. The shift in energy 

use from electricity to natural gas consumption to meet the greater heating loads 

decreases energy costs because natural gas is cheaper on a per unit of energy basis 

relative to electricity. 

The LEC design leads to average percentage changes in energy-related carbon emissions 

ranging from -10.9 % to -31.6 %, depending on the building type, with an average 

of -18.1 % across all building types. For the LEC design, the percentage reduction in 

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Washington 

carbon emissions is greater than the percentage reduction in energy use for all 11 building 

types because the energy efficiency measures decrease electricity consumption by a 

greater percentage than natural gas consumption. The greater relative reduction in 

electricity leads to a greater reduction in carbon emissions because natural gas has a 

lower average carbon emissions rate than electricity. As mentioned above, the energy 

efficiency measures decrease electricity consumption while increasing natural gas 

consumption for 10 of the 11 building types. The combination of the reduction in total 

energy use and the shift in energy use from electricity consumption to natural gas 

consumption leads to even greater reductions in carbon emissions. 

The LEC design results in average reductions in life-cycle costs for a 10-year study 

period for 4 of 11 building types. The average percentage change in life-cycle costs for 

the LEC design ranges from -3.9 % to 1.4 %. The restaurant and 3- and 8-story office 

buildings realize the greatest average percentage reductions in life-cycle costs while the 

16-story office building and 4- and 6-story apartment buildings realize the greatest 

average percentage increases in life-cycle costs. Based on the overall average percentage 

reduction in life-cycle costs of -0.2 %, the LEC design may be cost-effective if the state 

adopted it as its state energy code for commercial buildings. 

17.1.2 City Comparisons 

Simulations are run for five cities located in Washington: Olympia, Quillayute, and 

Seattle in Climate Zone 4C, and Spokane and Yakima in Climate Zone 5B. Washington 

has no significant population centers located in Zone 6B. The results may vary across 

cities within the state for several reasons. First, the cities selected for the state cover two 

climate zones. The ASHRAE 90.1 building design requirements vary across climate zones 

and will impact the relative energy efficiency of the building. Second, cities within the 

same climate zone still have some variation in the local climate, which can lead to 

variation in energy consumption. Third, construction material and labor costs vary by 

locality. 

As can be seen in Table 17-3, the average percentage change in energy use for all 

building types from adopting the LEC design varies slightly across cities in the state, 

ranging from 12.5 % to 14.9 %. There is no distinct trend in energy use across climate 

zones or based on geographic location. The average reductions in energy costs and 

carbon emissions for all building types vary slightly across cities throughout the state, 

and are correlated with the reductions in energy use. 

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Washington 

Table 17-3 Average Percentage Change from Adoption of Newer Standard Editions 

by City, 10-Year, Washington 

Cities Zone LEC 

Energy Use Energy Cost Carbon LCC 

Olympia 4C -13.7 -16.9 -18.2 -0.1 

Quillayute 4C -12.5 -15.8 -17.1 -0.3 

Seattle 4C -14.9 -17.9 -19.1 -0.0 

Spokane 5B -12.8 -16.0 -17.3 -0.4 

Yakima 5B -14.3 -17.5 -18.9 -0.2 

Average -13.6 -16.8 -18.1 -0.2 

The LEC design results in an average percentage reduction in life-cycle costs relative to 

ASHRAE 90.1-2007 across all cities in the state, ranging from 0.0 % to 0.4 %. These cost 

variations are probably a result of the variation in building envelope design requirements 

across climate zones combined with different local construction costs across the state. 

Cities located further north realize smaller percentage reductions in life-cycle costs. 

17.2 Total Savings 

How much can Washington save, in terms of energy use, energy costs, and carbon 

emissions, from adopting a more stringent state energy code for commercial buildings? 

What are the life-cycle costs associated with the new energy code adoption? To answer 

these questions, it is necessary to estimate savings per unit of floor area for each building 

type in the state. 

17.2.1 Energy Use 

Table 17-4 reports the average per unit change in annual energy use by building type for 

the LEC design in the state.38 The reduction per m2 (ft2

) is multiplied by the estimated m2 

(ft2) of new construction of each building type, and Table 17-5 reports the estimated 

average annual floor area of new construction and the total annual reduction in energy 

use for each building type. The weightings within a category (e.g., small, medium, and 

large office buildings) are based on the national average percentage of new building 

construction for the category that is represented by each subcategory.39 

38 A simple average for a state is used because no data for a weighted average is available regarding the 

amount of new construction on a city-by-city basis. 

39 State-level subcategory data are not available. 

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Washington 

Table 17-4 Average Per Unit Change in Annual Energy Use, Washington
 

Building Standard Edition 

Type LEC 

kWh/m2 kBtu/ft2 

APART04 -11.7 -3.7 

APART06 -12.6 -4.0 

DORMI04 -12.1 -3.8 

DORMI06 -13.5 -4.3 

HIGHS02 -17.8 -5.6 

HOTEL15 -19.2 -6.1 

OFFIC03 -8.7 -2.8 

OFFIC08 -18.2 -5.8 

OFFIC16 -22.2 -7.0 

RETAIL1 -13.2 -4.2 

RSTRNT1 -38.6 -12.2 

The annual reduction in energy use shown in Table 17-5 ranges widely across building 

types, but the LEC design decreases overall energy use across the state relative to 

ASHRAE 90.1-2007. The adoption of the LEC design as the state’s energy code would 

save energy for all building types, and 31.6 GWh (107.7 GBtu) of total energy use 

annually for one year’s worth of new construction for these building types. Assuming that 

the buildings considered in this study, which represent 60.1 % of all new commercial 

floor space in the state, are generally representative of the entire new commercial 

building stock in the state, the results can be extrapolated to estimate total statewide 

savings to be 52.5 GWh (179.3 GBtu) per year. These savings imply 525.0 GWh 

(1792.7 GBtu) in energy savings over the 10-year study period. 

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Washington 

Table 17-5 Statewide Change in Annual Energy Use for One Year of Construction, 

Washington 

Building Subcategory m 2 ft2 Standard Edition 

Type Weighting (1000s) (1000s) LEC 

kWh kBtu 

APART04 44.9 % 305 3287 -3 584 523 -12 239 103
 

APART06 55.1 % 374 4026 -4 714 266 -16 096 532
 

HOTEL15 100.0 % 174 1876 -3 099 194 -10 581 980 

HIGHS02 100.0 % 368 3963 -3 213 703 -10 972 965 

OFFIC03 37.4 % 182 1962 -3 504 914 -11 967 283 

OFFIC08 40.4 % 197 2116 -3 580 610 -12 225 744 

OFFIC16 22.2 % 108 1164 -2 401 406 -8 199 434 

RETAIL1 100.0 % 501 5391 -6 633 348 -22 649 103 

RSTRNT1 100.0 % 21 229 -822 281 -2 807 620 

Total 2231 24 014 -31 554 246 -107 739 765 

Note: Dormitories are excluded because no such floor area category is reported in 

the construction data. 

The change in energy use varies across the 9 building types with reported floor area data. 

The building types that have the greatest percentage reductions in energy use are not 

always the same buildings that lead to the greatest total reductions for the state. Instead 

the building types that represent a greater amount of new floor area realize the largest 

changes in energy use. The amount of new construction overwhelms the relative 

percentage changes in energy use. The building types that lead to the greatest estimated 

reduction in energy use for the LEC design -- retail stores and 8-story office buildings -­

only rank 5th and 2nd in percentage reduction, respectively, among the 11 building types, 

as reported in Table 17-2. 

17.2.2 Energy Costs 

Table 17-6 reports the average per unit change in energy costs by building type. Energy 

costs are calculated using the annual energy use, state average energy cost rates, and 

regional energy price escalation rates as defined in Section 3.2. 

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Washington 

Table 17-6 Average Per Unit Change in Energy Costs, 10-Year, Washington
 

Building Standard Edition 

Type LEC 

$/m2 $/ft2 

APART04 -$7.26 -$0.67 

APART06 -$8.18 -$0.76 

DORMI04 -$6.88 -$0.64 

DORMI06 -$8.74 -$0.81 

HIGHS02 -$10.05 -$0.93 

HOTEL15 -$10.89 -$1.01 

OFFIC03 -$7.97 -$0.74 

OFFIC08 -$10.14 -$0.94 

OFFIC16 -$12.80 -$1.19 

RETAIL1 -$7.24 -$0.67 

RSTRNT1 -$21.36 -$1.98 

Table 17-7 reports the statewide changes in total energy costs by building type, which 

account for one year’s worth of new construction evaluated over 10 years of building 

operation. Overall, the reduction in energy costs total $19.4 million for adopting the LEC 

design relative to ASHRAE 90.1-2007. All building types realize energy cost savings for 

the LEC design. The greatest energy cost savings are realized by the retail stores, 6-story 

apartment buildings, and high schools. The smallest reductions in energy costs are 

realized by restaurants. Assuming that the buildings considered in this study, which 

represent 60.1 % of all new floor space in the state, are generally representative of the 

entire new commercial building stock in the state, the results for the LEC design can be 

extrapolated to estimate total statewide energy cost savings of $32.3 million over the 10­

year study period. 

Table 17-7 Statewide Change in Energy Costs for One Year of Construction, 

10-Year, Washington 

Building Subcategory m 2 ft2 Standard Edition
 

Type Weighting (1000s) (1000s) LEC
 

APART04 44.9 % 305 3287 -$2 215 913
 

APART06 55.1 % 374 4026 -$3 061 508
 

HOTEL15 100.0 % 174 1876 -$1 750 958 

HIGHS02 100.0 % 368 3963 -$2 935 810 

OFFIC03 37.4 % 182 1962 -$1 985 464 

OFFIC08 40.4 % 197 2116 -$1 992 427 

OFFIC16 22.2 % 108 1164 -$1 384 175 

RETAIL1 100 % 501 5391 -$3 626 508 

RSTRNT1 100 % 21 229 -$455 238 

Total 2231 24 014 -$19 408 003 

Note: Dormitories are excluded because no such floor area category is 

reported in the construction data. 

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Washington 

17.2.3 Energy-related Carbon Emissions 

Table 17-8 reports the average energy-related reduction in carbon emissions over 10 

years, per m 2 (ft2), by building type. The carbon emissions estimation approach is defined 

in Section 5.3. 

Table 17-8 Average Per Unit Change in Carbon Emissions, 10-Year, Washington 

Building Standard Edition 

Type LEC 

kg/m2 lb/ft2 

APART04 -66.6 -13.6 

APART06 -75.7 -15.5 

DORMI04 -62.1 -12.7 

DORMI06 -80.8 -16.6 

HOTEL15 -90.6 -18.6 

HIGHS02 -77.4 -15.8 

OFFIC03 -98.3 -20.1 

OFFIC08 -91.1 -18.7 

OFFIC16 -115.9 -23.7 

RETAIL1 -64.9 -13.3 

RSTRNT1 -191.9 -39.3 

Table 17-9 applies the Table 17-8 results to one year’s worth of new building 

construction in the state to estimate statewide energy-related reductions in carbon 

emissions from adoption of the LEC design. The total reduction in carbon emissions 

ranges widely across building types, and is correlated with the reductions in energy use. 

The adoption of the LEC design as the state’s energy code for commercial buildings 

decreases carbon emissions by 177 881 metric tons over the 10-year study period for one 

year’s worth of new commercial construction for these building types. Assuming that the 

buildings considered in this study are generally representative of the entire new building 

stock in the state, the results for the LEC design can be extrapolated to estimate total 

statewide reductions in carbon emissions of 266 687 metric tons over the 10-year study 

period. 

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Washington 

Table 17-9 Statewide Change in Total Carbon Emissions (t) for One Year of 

Construction, 10-Year, Washington – Metric Tons 

Building Subcategory m 2 ft2 Standard Edition
 

Type Weighting (1000s) (1000s) LEC
 

APART04 44.9 % 305 3287 -20 328
 

APART06 55.1 % 374 4026 -28 327
 

HOTEL15 100.0 % 174 1876 -15 792 

HIGHS02 100.0 % 368 3963 -28 491 

OFFIC03 37.4 % 182 1962 -17 916 

OFFIC08 40.4 % 197 2116 -17 915 

OFFIC16 22.2 % 108 1164 -12 533 

RETAIL1 100.0 % 501 5391 -32 490 

RSTRNT1 100.0 % 21 229 -4089 

Total 2231 24 014 -177 881 

Note: Dormitories are excluded because no such floor area category is 

reported in the construction data. 

17.2.4 Life-Cycle Costs 

Table 17-10 reports the average change in life-cycle cost over 10 years, per m2 (ft2

), by 

building type. As discussed in Section 5.2, life-cycle costs include construction costs, 

maintenance, repair, and replacement costs, energy costs, and residual values. The 

average change in life-cycle costs per unit of floor area varies significantly across 

building types. 

Table 17-10 Average Per Unit Change in Life-Cycle Costs, 10-Year, Washington 

Building Standard Edition 

Type LEC 

$/m2 $/ft2 

APART04 $12.15 $1.13 

APART06 $11.94 $1.11 

DORMI03 -$4.56 -$0.42 

DORMI06 $9.12 $0.85 

HOTEL15 $10.67 $0.99 

HIGHS02 $1.92 $0.18 

OFFIC03 -$21.78 -$2.02 

OFFIC08 -$18.87 -$1.75 

OFFIC16 $11.08 $1.03 

RETAIL1 $7.41 $0.69 

RSTRNT1 -$50.53 -$4.69 

Table 17-11 applies the Table 17-10 results to one year’s worth of new building 

construction in the state to estimate statewide change in total life-cycle costs from 

adoption of the LEC design. Adopting the LEC design increases total life-cycle costs by 

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Washington 

$6.9 million, and reduces costs for three of the nine building types. Three-story and 

8-story office buildings realize the greatest reductions in life-cycle costs while the 

apartment buildings and retail stores realize the greatest increases in life-cycle costs. 

Assuming that the buildings considered in this study are generally representative of the 

entire new building stock in the state, the results for the LEC design can be extrapolated 

to estimate an increase in total statewide life-cycle costs of $11.5 million over the 10-year 

study period. 

Table 17-11 Statewide Change in Life-Cycle Costs for One Year of Construction, 

10-Year, Washington 

Building Subcategory m 2 ft2 Standard Edition
 

Type Weighting (1000s) (1000s) LEC
 

APART04 44.9 % 305 3287 $3 709 628 

APART06 55.1 % 374 4026 $4 465 686 

HOTEL15 100.0 % 174 1876 $1 859 063 

HIGHS02 100.0 % 368 3963 $705 477 

OFFIC03 37.4 % 182 1962 -$3 969 185 

OFFIC08 40.4 % 197 2116 -$3 709 139 

OFFIC16 22.2 % 108 1164 $1 197 957 

RETAIL1 100.0 % 501 5391 $3 710 487 

RSTRNT1 100.0 % 21 229 -$1 076 982 

Total 2231 24 014 $6 892 993 

Note: Dormitories are excluded because no such floor area category is 

reported in the construction data. 

17.3 State Summary 

Washington has adopted ASHRAE 90.1-2007 as its state energy code for commercial 

buildings. The adoption of the LEC design, which goes beyond ASHRAE 90.1-2007, 

leads to sizeable total energy use, energy cost, and carbon emissions reductions while 

increasing life-cycle costs. Based on the average annual new commercial construction in 

the state from 2003 to 2007 and a 10-year study period, adopting the LEC design as the 

state’s energy code for commercial buildings would lead to energy savings of 525.0 GWh 

(1792.7 GBtu), energy cost savings of $32.3 million, and carbon emissions savings of 

266 687 metric tons while increasing life-cycle costs by $11.5 million for one year’s 

worth of commercial building construction. Washington is one of two states in this report 

that realize an increase in life-cycle costs from adopting the LEC design. 

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Wyoming 

18 Wyoming 

Wyoming is located in the Mountain Census Division and spans three climate zones 

(Zone 5B, Zone 6B, and Zone 7). The state does not have a commercial building energy 

code, and is assumed to build to the current minimum industry practices represented by 

ASHRAE 90.1-1999 requirements. Table 18-1 provides an overview of Wyoming’s 

simulated energy use keyed to building types and energy standard editions. Average 

energy use varies across building types and building designs. The 8-story office building 

uses the least amount of energy at 82 kWh/m2 to 116 kWh/m2 (26 kBtu/ft2 to 37 kBtu/ft2

) 

annually. The high school uses the greatest amount of energy at 227 kWh/m2 to 257 

kWh/m2 (72 kBtu/ft2 to 81 kBtu/ft2) annually. 

Table 18-1 Average Annual Energy Use by Building Type and Standard Edition, 

Wyoming 

Building 

Type 

Standard Edition 

1999 

kWh/m2 kBtu/ft2 

2001 

kWh/m2 kBtu/ft2 

2004 

kWh/m2 kBtu/ft2 

2007 

kWh/m2 kBtu/ft2 

LEC 

kWh/m2 kBtu/ft2 

APART04 

APART06 

175 56 

171 54 

175 55 

171 54 

160 51 

156 49 

151 48 

149 47 

135 43 

133 42 

DORMI04 

DORMI06 

140 45 

187 59 

139 44 

186 59 

129 41 

170 54 

120 38 

167 53 

103 33 

151 48 

HOTEL15 171 54 170 54 156 49 164 52 147 47 

HIGHS02 257 81 256 81 252 80 243 77 227 72 

OFFIC03 

OFFIC08 

OFFIC16 

126 40 

116 37 

157 50 

124 39 

114 36 

156 49 

117 37 

105 33 

147 47 

109 35 

100 32 

156 50 

88 28 

82 26 

137 43 

RETAIL1 153 48 152 48 142 45 127 40 106 34 

RSTRNT1 216 69 213 68 200 63 168 53 125 40 

The detailed analysis for this state reports the changes in energy use, energy costs, 

energy-related carbon emissions, and life-cycle costs from adoption of increasingly 

stringent energy standard editions. The results are reported in terms of average 

percentage savings on a statewide and city-by-city basis and as total savings on a 

statewide basis. 

18.1 Percentage Savings 

Changes in percentage terms allow for direct comparisons across building types and 

locations within a state. This section discusses the average percentage changes from 

investing in more energy efficient designs for the state of Wyoming. 

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Wyoming 

18.1.1 Energy Use 

Table 18-2 shows a small change in energy use from adopting ASHRAE 90.1-2001 

relative to ASHRAE 90.1-1999, with all 11 building types realizing a reduction of 1.8 % 

or less. There is significant variation in the decrease in energy use across the 11 building 

types from adopting the ASHRAE 90.1-2004 design, with the percentage ranging 

from -1.8 % to -9.8 % with an average of -7.6 %. 

Table 18-2 Average Percentage Change in Energy Use from Adoption of Newer 

Standard Editions, Wyoming 

Building Standard Edition 

Type 2001 2004 2007 LEC 

APART04 -0.4 -8.8 -13.7 -22.7 

APART06 -0.4 -9.1 -13.3 -22.5 

DORMI04 -1.1 -8.4 -14.9 -26.9 

DORMI06 -0.4 -8.9 -10.6 -19.1 

HOTEL15 -0.7 -8.9 -4.0 -13.8 

HIGHS02 -0.4 -1.8 -5.2 -11.5 

OFFIC03 -1.4 -7.1 -13.3 -30.1 

OFFIC08 -1.8 -9.8 -13.7 -29.2 

OFFIC16 -0.8 -6.1 -0.4 -12.8 

RETAIL1 -0.7 -7.2 -16.9 -30.5 

RSTRNT1 -1.4 -7.4 -22.4 -42.3 

Average -0.9 -7.6 -11.7 -23.8 

The average change in energy use from constructing buildings using ASHRAE 90.1-2007 

requirements ranges from -0.4 % to -22.4 %, with an overall average of -11.7 %. For the 

high-rise, 100 % glazed buildings (16-story office building and 15-story hotel), ASHRAE 

90.1-2004 is actually more energy efficient than ASHRAE 90.1-2007 because the 

maximum allowable window SHGC in Zone 6 is increased from ASHRAE 90.1-2004 to 

ASHRAE 90.1-2007 for buildings with fenestration accounting for greater than 40 % of 

total wall surface area. The 100 % glazing amplifies the impact of this requirement 

relaxation enough to overwhelm the energy efficiency gains obtained from other 

measures, such as increased insulation R-values. 

The LEC design realizes the greatest reductions in energy use, with the change in energy 

use relative to ASHRAE 90.1-1999 ranging from -11.5 % to -42.3 % with an average 

of -23.8 %. The smallest reduction for the LEC design occurs in the high school, 16-story 

office building, and hotel. For the high-rise buildings, these small reductions are a result 

of the 100 % glazing combined with the relaxed SHGC requirement. The high school 

realizes small reductions in energy use because of its unique occupant activity, significant 

occupancy during the school year and minimal occupancy during the summer. 

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Wyoming 

18.1.2 Energy Costs 

Table 18-3 shows a small percentage change in energy costs over 10 years from adopting 

ASHRAE 90.1-2001 (-0.5 % to -2.0 %), which mirrors the energy use results described 

above. There is a significant variation in the percentage change in average energy costs 

for ASHRAE 90.1-2004, ranging from -6.9 % to -21.2 % depending on the building type 

with an average of -15.7 %. The average change in energy costs from constructing 

buildings using ASHRAE 90.1-2007 requirements ranges from -3.8 % to -24.6 %, with an 

overall average of -17.4 %. The LEC design realizes the greatest change in energy costs, 

ranging from -16.2 % to -46.2 % with an average of -31.7 % overall. 

Table 18-3 Average Percentage Change in Energy Costs, 10-Year, Wyoming 

Building Standard Edition 

Type 2001 2004 2007 LEC 

APART04 -0.5 -21.0 -24.0 -36.6 

APART06 -0.6 -21.2 -23.7 -36.3 

DORMI04 -1.5 -21.2 -24.6 -38.4 

DORMI06 -0.6 -20.8 -21.8 -33.4 

HOTEL15 -0.9 -19.9 -14.3 -24.7 

HIGHS02 -0.6 -6.9 -9.4 -21.2 

OFFIC03 -1.6 -11.0 -13.6 -31.8 

OFFIC08 -2.0 -12.6 -14.0 -30.1 

OFFIC16 -1.0 -10.2 -3.8 -16.2 

RETAIL1 -0.9 -13.4 -18.9 -34.0 

RSTRNT1 -1.8 -14.7 -22.9 -46.2 

Average -1.1 -15.7 -17.4 -31.7 

Adoption of the ASHRAE 90.1-2004, ASHRAE 90.1-2007, and LEC designs lead to 

average reductions in energy costs that are greater than the reductions in energy use for 

all 11 building types. Each of these building types realizes a greater percentage reduction 

in electricity consumption than natural gas consumption. Since electricity is more 

expensive than natural gas on a per unit of energy basis, the average reduction in energy 

costs is increased for the building. 

18.1.3 Energy-related Carbon Emissions 

Minimal change in energy use leads to small percentage reductions (2.0 % or less) in 

cradle-to-grave energy-related carbon emissions for the ASHRAE 90.1-2001 design 

across all building types. Table 18-4 shows a significant change in average energy-related 

carbon emissions for ASHRAE 90.1-2004 for all building types, ranging from -6.8 % 

to -21.1 % with an average of -15.6 %. The ASHRAE 90.1-2007 design leads to slightly 

greater reductions overall than ASHRAE 90.1-2004, with the average change in carbon 

emissions ranging from -3.7 % to -24.5 % with an overall average of -17.3 %. The LEC 

design leads to the greatest average changes in carbon emissions, ranging from -16.1 % 

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Wyoming 

to -46.1 % depending on the building type with an average of -31.6 % across all building 

types. 

Table 18-4 Average Percentage Change in Energy-related Carbon Emissions, 10­

Year, Wyoming 

Building Standard Edition 

Type 2001 2004 2007 LEC 

APART04 -0.5 -20.8 -23.9 -36.4 

APART06 -0.6 -21.1 -23.6 -36.2 

DORMI04 -1.4 -21.1 -24.5 -38.3 

DORMI06 -0.6 -20.7 -21.7 -33.2 

HOTEL15 -0.9 -19.7 -14.2 -24.6 

HIGHS02 -0.6 -6.8 -9.3 -21.1 

OFFIC03 -1.6 -10.9 -13.6 -31.8 

OFFIC08 -2.0 -12.6 -14.0 -30.0 

OFFIC16 -1.0 -10.1 -3.7 -16.1 

RETAIL1 -0.9 -13.4 -18.9 -34.0 

RSTRNT1 -1.8 -14.6 -22.9 -46.1 

Average -1.1 -15.6 -17.3 -31.6 

As would be expected, a more energy efficient building design results in greater 

reductions in carbon emissions. Similar to energy costs, all building types realize greater 

percentage reductions in carbon emissions than the percentage changes in energy use 

because the energy efficiency measures decrease electricity consumption by a greater 

percentage than natural gas consumption. The relatively greater reduction in electricity 

increases the overall average emissions rate per unit of reduction in energy use. 

18.1.4 Life-Cycle Costs 

The most cost-effective building design for each building type is bolded in Table 18-5. 

Life-cycle costs increase for the ASHRAE 90.1-2001 design compared to ASHRAE 

90.1-1999 for all 11 building types over a 10-year study period. The current state energy 

code is the lowest cost option for three building types. ASHRAE 90.1-2004 and ASHRAE 

90.1-2007 are the lowest cost building design for two and four building types, 

respectively. The change in life-cycle costs for ASHRAE 90.1-2004 and -2007 range 

from -2.3 % to 4.0 % depending on building type. The LEC design is the lowest cost 

building design for two building types and realizes a reduction in life-cycle costs for 6 of 

11 building types, with the change in life-cycle costs ranging from -1.8 % to 1.3 %. 

Based on the overall average percentage change in life-cycle costs of -0.5 %, the LEC 

design may be cost-effective if the state adopted it as its state energy code for commercial 

buildings. 

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Table 18-5 Average Percentage Change in Life-Cycle Costs, 10-Year, Wyoming 

Building Standard Edition 

Type 2001 2004 2007 LEC 

APART04 0.1 -1.6 -2.0 -1.4 

APART06 0.0 -1.6 -1.9 -1.3 

DORMI04 3.5 0.9 0.4 -0.9 

DORMI06 0.0 -2.1 -2.2 -1.8 

HOTEL15 0.0 -2.3 -1.8 -1.3 

HIGHS02 0.6 -0.1 -0.6 -1.3 

OFFIC03 5.1 2.5 2.2 0.3 

OFFIC08 5.2 2.5 2.2 0.7 

OFFIC16 0.0 -1.0 -0.4 0.1 

RETAIL1 2.7 0.3 -0.9 0.4 

RSTRNT1 6.8 4.0 1.6 1.3 

Average 2.2 0.1 -0.3 -0.5 

18.1.5 City Comparisons 

Simulations are run for five cities located in Wyoming, all of which are located in 

Zone 6B: Casper, Cheyenne, Lander, Rock Springs, and Sheridan. There are no 

significant population centers in the counties of Wyoming located in Zone 5B or 

Zone 7.While the cities are all located in Zone 6B, the results may still vary for two 

reasons. First, cities within the same climate zone may have some variation in the local 

climate, which can lead to variation in energy consumption. Second, construction 

material and labor costs may vary significantly by locality. 

As can be seen in Table 18-6, average reductions in energy use for all building types 

from adopting newer energy standard editions vary minimally within the climate zone. 

The variation between cities from adopting the ASHRAE 90.1-2001, -2004, -2007, and 

LEC designs is 0.1, 1.7, 1.2, and 1.8 percentage points, respectively. There is minimal 

impact on energy use from variation in weather within the climate zone. 

Table 18-6 Average Percentage Change in Energy Use from Adoption of Newer 

Standard Editions by City, Wyoming 

Cities Zone Standard Edition 

2001 2004 2007 LEC 

Casper 6B -0.8 -7.6 -11.6 -23.7 

Cheyenne 6B -0.8 -8.3 -12.3 -24.9 

Lander 6B -0.9 -8.0 -11.9 -24.0 

Rock Springs 6B -0.9 -6.6 -11.1 -23.2 

Sheridan 6B -0.9 -7.5 -11.4 -23.1 

Average -0.9 -7.6 -11.7 -23.8 

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The variations in energy costs across cities are a result of two factors, the reductions in 

energy use and the fuel source of the reductions. Table 18-7 shows that percentage 

reductions in energy costs are greater than percentage reductions in energy use because 

the percentage reduction in electricity consumption is greater than the reduction in natural 

gas consumption. Similar to energy use, there is minimal variation in energy costs across 

cities in Wyoming for all building designs. 

Table 18-7 Average Percentage Change in Energy Costs by City, 10-Year, 

Wyoming 

Cities Zone Standard Edition 

2001 2004 2007 LEC 

Casper 6B -1.1 -15.4 -17.0 -31.3 

Cheyenne 6B -1.0 -16.1 -17.6 -32.3 

Lander 6B -1.1 -15.6 -17.1 -31.5 

Rock Springs 6B -1.1 -16.4 -18.3 -32.5 

Sheridan 6B -1.1 -15.2 -16.8 -30.9 

Average -1.1 -15.7 -17.4 -31.7 

Table 18-8 reports changes in energy-related carbon emissions by city for Wyoming. For 

all cities, the more stringent standard editions result in greater reductions in carbon 

emissions. Similar to energy costs, the percentage reductions in carbon emissions are 

greater than percentage reductions in energy use because the percentage reduction in 

electricity consumption is greater than the reduction in natural gas consumption. There is 

minimal variation in carbon emissions across cities in Wyoming for all building designs. 

Table 18-8 Average Percentage Change in Carbon Emissions by City, 10-Year, 

Wyoming 

Cities Zone Standard Edition 

2001 2004 2007 LEC 

Casper 6B -1.0 -14.6 -16.6 -31.1 

Cheyenne 6B -0.9 -15.3 -17.2 -32.1 

Lander 6B -1.0 -14.8 -16.7 -31.3 

Rock Springs 6B -1.0 -15.5 -17.8 -32.2 

Sheridan 6B -1.0 -14.5 -16.4 -30.7 

Average -1.0 -15.0 -17.0 -31.5 

The data reported in Table 18-9 show that, over a 10-year period, average life-cycle costs 

increase for all cities for the ASHRAE 90.1-2001 design and four of five cities for the 

ASHRAE 90.1-2004 design compared to ASHRAE 90.1-1999. Adoption of the ASHRAE 

90.1-2007 and LEC designs results in average reductions in life-cycle costs for all cities 

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relative to ASHRAE 90.1-1999. Adoption of the LEC design realizes the greatest average 

percentage reductions in life-cycle costs for all cities. Rock Springs realizes greater 

percentage reductions in life-cycle costs relative to the other four cities, which may be a 

result of variation in local construction costs. 

Table 18-9 Average Percentage Change in Life-Cycle Costs by City, 10-Year, 

Wyoming 

Cities Zone Standard Edition 

2001 2004 2007 LEC 

Casper 6B 2.2 0.2 -0.2 -0.4 

Cheyenne 6B 2.1 0.2 -0.3 -0.3 

Lander 6B 2.2 0.2 -0.2 -0.4 

Rock Springs 6B 2.3 -0.2 -0.6 -0.9 

Sheridan 6B 2.1 0.2 -0.2 -0.4 

Average 2.2 0.1 -0.3 -0.5 

18.2 Total Savings 

How much can Wyoming save, in terms of energy use, energy costs, and carbon 

emissions, from adopting a more stringent state energy code for commercial buildings? 

What are the life-cycle costs associated with the new energy code adoption? To answer 

these questions, it is necessary to estimate savings per unit of floor area for each building 

type in the state. 

18.2.1 Energy Use 

Table 18-10 reports the average per unit change in annual energy use by building type 

and building design in the state.40 The reduction per m2 (ft2

) is multiplied by the 

estimated m2 (ft2) of new construction of each building type, and Table 18-11 reports the 

estimated average annual floor area of new construction and the total annual change in 

energy use for each building type. The weightings within a category (e.g., small, medium, 

and large office buildings) are based on the national average percentage of new building 

construction for the category that is represented by each subcategory.41 

40 A simple average for a state is used because no data for a weighted average is available regarding the
 

amount of new construction on a city-by-city basis.
 

41 State-level subcategory data are not available.
 

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Table 18-10 Average Per Unit Change in Annual Energy Use, Wyoming
 

Building Standard Edition 

Type 2001 

kWh/m2 kBtu/ft2 

2004 

kWh/m2 kBtu/ft2 

2007 

kWh/m2 kBtu/ft2 

LEC 

kWh/m2 kBtu/ft2 

APART04 

APART06 

-0.7 -0.2 

-0.7 -0.2 

-15.4 -4.9 

-15.6 -4.9 

-24.0 -7.6 

-22.9 -7.3 

-39.8 -12.6 

-38.5 -12.2 

DORMI04 

DORMI06 

-1.5 -0.5 

-0.8 -0.3 

-11.7 -3.7 

-16.6 -5.3 

-20.9 -6.6 

-19.7 -6.3 

-37.8 -12.0 

-35.7 -11.3 

HOTEL15 -1.1 -0.4 -15.1 -4.8 -6.7 -2.1 -23.6 -7.5 

HIGHS02 -1.0 -0.3 -8.9 -2.8 -16.8 -5.3 -37.8 -12.0 

OFFIC03 

OFFIC08 

OFFIC16 

-1.7 -0.5 

-2.1 -0.7 

-1.2 -0.4 

-4.6 -1.5 

-11.3 -3.6 

-9.6 -3.0 

-13.4 -4.3 

-15.9 -5.0 

-0.6 -0.2 

-29.5 -9.4 

-33.8 -10.7 

-20.1 -6.4 

RETAIL1 -1.1 -0.3 -11.0 -3.5 -25.8 -8.2 -46.7 -14.8 

RSTRNT1 -3.0 -1.0 -16.1 -5.1 -48.3 -15.3 -91.4 -29.0 

The annual reduction in energy use shown in Table 18-11 ranges widely across building 

designs, but all building designs decrease overall energy use across the state relative to 

ASHRAE 90.1-1999. Adopting the ASHRAE 90.1-2001, ASHRAE 90.1-2004, and 

ASHRAE 90.1-2007 designs result in annual decreases of 152 MWh (520 MBtu), 1.3 

GWh (4.3 GBtu), and 2.0 GWh (6.8 GBtu), respectively. The adoption of the LEC design 

as the state’s energy code would save energy for all building types and 4.4 GWh 

(14.9 GBtu) of total energy use annually for one year’s worth of new construction for 

these building types. 

Table 18-11 Statewide Change in Annual Energy Use for One Year of Construction, 

Wyoming 

Building 

Type 

Subcat. 

Weight. m 2 

(1000s) 

ft2 

(1000s) 

Standard Edition 

2001 

MWh MBtu 

2004 

MWh MBtu 

2007 

kWh kBtu 

LEC 

kWh kBtu 

APART04 

APART06 

44.9 % 

55.1 % 

0 

0 

4 

5 

-0 -1 

-0 -1 

-5 -18 

-7 -23 

-8 -29 

-10 -34 

-14 -48 

-17 -56 

HOTEL15 100.0 % 33 357 -37 -128 -503 -1717 -224 -765 -784 -2676 

HIGHS02 100.0 % 51 547 -51 -173 -235 -802 -684 -2335 -1499 -5120 

OFFIC03 

OFFIC08 

OFFIC16 

37.4 % 

40.4 % 

22.2 % 

5 

5 

3 

53 

58 

32 

-8 -29 

-11 -39 

-4 -12 

-44 -151 

-60 -207 

-28 -97 

-83 -284 

-85 -291 

-2 -6 

-188 -640 

-181 -618 

-59 -202 

RETAIL1 100.0 % 32 339 -35 -118 -347 -1183 -812 -2772 -1470 -5020 

RSTRNT1 100.0 % 2 19 -5 -19 -29 -99 -87 -297 -165 -563 

Total 131 1414 -152 -520 -1258 -4296 -1995 -6812 -4376 -14 942 

Note: Dormitories are excluded because no such floor area category is reported in the construction data. 

Assuming that the buildings considered in this study, which represent 57.1% of all new 

commercial floor space in the state, are generally representative of the entire new 

commercial building stock in the state, the results can be extrapolated to estimate the total 

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statewide savings from adopting the LEC design in new commercial buildings to be 

7.7 GWh (26.2 GBtu) per year. These savings imply 76.6 GWh (261.7 GBtu) in energy 

use savings over the 10-year study period. In comparison, ASHRAE 90.1-2007 would 

save 3.5 GWh (11.9 GBtu) annually or 34.9 GWh (119.3 GBtu) over the 10-year study 

period. 

The statewide change in energy use across the 9 building types with reported floor area 

data varies across and within building designs. The building types that represent the 

greatest amount of new floor area have a greater impact on aggregate reductions in 

energy use regardless of their relative percentage reductions. The greatest total reductions 

are realized by retail stores, high schools, and hotels because they represent 24.0 %, 

38.7 %, and 25.3 %, respectively, of the combined new construction in the state for the 

building types in this study while all other building types represent 4.1 % or less. The 

building types that have the greatest percentage reduction in energy use are not always 

the same buildings that lead to the greatest total reductions for the state. These same three 

building types -- retail stores, high schools, and hotels -- rank 2nd, 11th, and 9th in 

percentage reduction, respectively, among the 11 building types, as reported in Table 

18-2. 

18.2.2 Energy Costs 

Table 18-12 reports the average per unit change in energy costs by building type and 

building design. Energy costs are calculated using the annual energy use, state average 

energy cost rates, and regional energy price escalation rates as defined in Section 3.2. 

Table 18-12 Average Per Unit Change in Energy Costs, 10-Year, Wyoming 

Building Standard Edition 

Type 2001 

$/m2 $/ft2 

2004 

$/m2 $/ft2 

2007 

$/m2 $/ft2 

LEC 

$/m2 $/ft2 

APART04 

APART06 

-$0.38 

-$0.40 

-$0.04 

-$0.04 

-$15.06 

-$15.14 

-$1.40 

-$1.41 

-$17.23 

-$16.93 

-$1.60 

-$1.57 

-$26.29 

-$25.97 

-$2.44 

-$2.41 

DORMI04 

DORMI06 

-$0.88 

-$0.46 

-$0.08 

-$0.04 

-$12.81 

-$16.22 

-$1.19 

-$1.51 

-$14.83 

-$16.98 

-$1.38 

-$1.58 

-$23.17 

-$25.97 

-$2.15 

-$2.41 

HOTEL15 -$0.65 -$0.06 -$14.37 -$1.34 -$10.33 -$0.96 -$17.86 -$1.66 

HIGHS02 -$0.98 -$0.09 -$6.70 -$0.62 -$8.34 -$0.77 -$19.45 -$1.81 

OFFIC03 

OFFIC08 

OFFIC16 

-$0.58 

-$1.23 

-$0.72 

-$0.05 

-$0.11 

-$0.07 

-$6.30 

-$7.60 

-$7.60 

-$0.59 

-$0.71 

-$0.71 

-$8.55 

-$8.45 

-$2.82 

-$0.79 

-$0.79 

-$0.26 

-$19.34 

-$18.14 

-$12.05 

-$1.80 

-$1.69 

-$1.12 

RETAIL1 -$0.63 -$0.06 -$9.12 -$0.85 -$12.85 -$1.19 -$23.07 -$2.14 

RSTRNT1 -$1.74 -$0.16 -$13.86 -$1.29 -$21.65 -$2.01 -$43.54 -$4.04 

Table 18-13 reports the statewide changes in total energy costs by building type and 

building design, which account for one year’s worth of new construction evaluated over 

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10 years of building operation. All building types realize reductions in energy costs for 

all building designs. The ASHRAE 90.1-2001 design realizes the smallest reductions in 

energy costs ($112 544). ASHRAE 90.1-2004, ASHRAE 90.1-2007, and the LEC design 

realize decreases in energy costs of $1.4 million, $1.5 million, and $3.0 million, 

respectively. Assuming that the buildings considered in this study, which represent 

57.1 % of all new commercial floor space in the state, are generally representative of the 

entire new commercial building stock in the state, the results for ASHRAE 90.1-2001, 

ASHRAE 90.1-2004, ASHRAE 90.1-2007, and the LEC design can be extrapolated to 

estimate statewide reductions in energy costs of $197 099, $2.4 million, $2.6 million, and 

$5.3 million over the 10-year study period, respectively. 

Table 18-13 Statewide Change in Energy Costs for One Year of Construction, 

10-Year, Wyoming 

Building Subcategory m 2 ft2 Standard Edition 

Type Weighting (1000s) (1000s) 2001 2004 2007 LEC 

APART04 44.9 % 0 4 -$639 -$25 282 -$28 915 -$44 127
 

APART06 55.1 % 0 5 -$814 -$31 127 -$34 816 -$53 387
 

HOTEL15 100.0 % 33 357 -$16 363 -$362 423 -$260 356 -$450 335 

HIGHS02 100.0 % 51 547 -$17 907 -$196 333 -$266 233 -$602 434 

OFFIC03 37.4 % 5 53 -$16 549 -$113 132 -$140 843 -$328 458 

OFFIC08 40.4 % 5 58 -$22 419 -$138 464 -$153 885 -$330 286 

OFFIC16 22.2 % 3 32 -$7170 -$76 112 -$28 209 -$120 720 

RETAIL1 100.0 % 32 339 -$26 264 -$379 698 -$535 000 -$960 020 

RSTRNT1 100.0 % 2 19 -$4418 -$35 277 -$55 102 -$110 826 

Total 131 1414 -$112 544 -$1 357 848 -$1 503 359 -$3 000 595 

Note: Dormitories are excluded because no such floor area category is reported in the construction data. 

18.2.3 Energy-related Carbon Emissions 

Table 18-14 reports the average reduction in energy-related carbon emissions over 

10 years, per m2 (ft2), by building type and building design. The carbon emissions 

estimation approach is defined in Section 5.3. 

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Table 18-14 Average Per Unit Change in Carbon Emissions, 10-Year, Wyoming
 

Building Standard Edition 

Type 2001 

kg/m2 lb/ft2 

2004 

kg/m2 lb/ft2 

2007 

kg/m2 lb/ft2 

LEC 

kg/m2 lb/ft2 

APART04 

APART06 

-4.4 -0.9 

-4.5 -0.9 

-172.4 -35.3 

-173.3 -35.5 

-197.5 -40.4 

-194.1 -39.7 

-301.5 -61.8 

-297.8 -61.0 

DORMI04 

DORMI06 

-10.1 -2.1 

-5.2 -1.1 

-146.5 -30.0 

-185.6 -38.0 

-170.0 -34.8 

-194.5 -39.8 

-265.9 -54.5 

-297.7 -61.0 

HOTEL15 -7.5 -1.5 -164.5 -33.7 -118.0 -24.2 -204.7 -41.9 

HIGHS02 -6.6 -1.4 -72.0 -14.8 -98.1 -20.1 -221.9 -45.4 

OFFIC03 

OFFIC08 

OFFIC16 

-11.3 -2.3 

-14.1 -2.9 

-8.2 -1.7 

-76.8 -15.7 

-87.2 -17.9 

-87.0 -17.8 

-95.9 -19.6 

-97.1 -19.9 

-32.1 -6.6 

-223.5 -45.8 

-208.4 -42.7 

-138.3 -28.3 

RETAIL1 -7.2 -1.5 -104.5 -21.4 -147.8 -30.3 -265.2 -54.3 

RSTRNT1 -19.9 -4.1 -158.7 -32.5 -249.1 -51.0 -500.7 -102.5 

Table 18-15 applies the Table 18-14 results to one year’s worth of new building 

construction in the state to estimate statewide reductions in carbon emissions from 

adoption of more energy efficient codes. The total reduction in carbon emissions ranges 

widely across building designs, but the ASHRAE 90.1-2001, ASHRAE 90.1-2004, 

ASHRAE 90.1-2007, and LEC designs decrease carbon emissions overall. The adoption 

of ASHRAE 90.1-2004 and ASHRAE 90.1-2007 result in savings of 13 943 metric tons 

and 15 252 metric tons over a 10-year study period, respectively. The adoption of the 

LEC design as the state’s energy code decreases carbon emissions by 30 201 metric tons 

over the 10-year study period for one year’s worth of new commercial construction for 

these building types. Assuming that the buildings considered in this study are generally 

representative of the entire new commercial building stock in the state, the results for the 

ASHRAE 90.1-2004, ASHRAE 90.1-2007, and LEC design can be extrapolated to 

estimate statewide reductions in carbon emissions of 24 419 metric tons, 26 710 metric 

tons, and 52 892 metric tons over the 10-year study period, respectively. 

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Table 18-15 Statewide Change in Total Carbon Emissions for One Year of 

Construction, 10-Year, Wyoming – Metric Tons 

Building Subcategory m 2 ft2 Standard Edition 

Type Weighting (1000s) (1000s) 2001 2004 2007 LEC 

APART04 44.9 % 0 4 -2 -60 -69 -106 

APART06 55.1 % 0 5 -2 -74 -83 -128 

HOTEL15 100.0 % 33 357 -247 -5463 -3917 -6796 

HIGHS02 100.0 % 51 547 -336 -3664 -4988 -11 284 

OFFIC03 37.4 % 5 53 -56 -381 -475 -1108 

OFFIC08 40.4 % 5 58 -76 -466 -519 -1114 

OFFIC16 22.2 % 3 32 -24 -256 -94 -407 

RETAIL1 100.0 % 32 339 -228 -3293 -4656 -8356 

RSTRNT1 100.0 % 2 19 -36 -286 -449 -902 

Total 131 1414 -1006 -13 943 -15 252 -30 201 

Note: Dormitories are excluded because no such floor area category is reported in the 

construction data. 

18.2.4 Life-Cycle Costs 

Table 18-16 reports the average change in life-cycle cost over 10 years, per m2 (ft2

), by 

building type and building design. As discussed in Section 5.2, life-cycle costs include 

construction costs, maintenance, repair, and replacement costs, energy costs, and residual 

values. 

Table 18-16 Average Per Unit Change in Life-Cycle Costs, 10-Year, Wyoming 

Building Standard Edition 

Type 2001 

$/m2 $/ft2 

2004 

$/m2 $/ft2 

2007 

$/m2 $/ft2 

LEC 

$/m2 $/ft2 

APART04 $0.64 $0.06 -$14.21 -$1.32 -$18.23 -$1.69 -$12.70 -$1.18 

APART06 $0.20 $0.02 -$14.49 -$1.35 -$17.38 -$1.61 -$11.27 -$1.05 

DORMI04 $29.33 $2.73 $7.68 $0.71 $2.91 $0.27 -$7.58 -$0.70 

DORMI06 -$0.05 $0.00 -$19.29 -$1.79 -$20.42 -$1.90 -$16.74 -$1.56 

HOTEL15 -$0.27 -$0.03 -$20.14 -$1.87 -$15.85 -$1.47 -$11.57 -$1.07 

HIGHS02 $4.53 $0.42 -$1.09 -$0.10 -$4.54 -$0.42 -$9.67 -$0.90 

OFFIC03 $35.27 $3.28 $17.06 $1.59 $15.33 $1.42 $1.75 $0.16 

OFFIC08 $37.22 $3.46 $17.84 $1.66 $15.97 $1.48 $4.89 $0.45 

OFFIC16 $0.01 $0.00 -$6.97 -$0.65 -$2.77 -$0.26 $0.57 $0.05 

RETAIL1 $15.46 $1.44 $1.60 $0.15 -$5.33 -$0.50 $2.11 $0.20 

RSTRNT1 $75.40 $7.01 $44.91 $4.17 $17.62 $1.64 $14.03 $1.30 

Table 18-17 applies the Table 18-16 results to one year’s worth of new building 

construction in the state to estimate statewide changes in life-cycle costs from adoption of 

more energy-efficient state energy codes for commercial buildings. Total changes in 

life-cycle costs over the 10-year study period vary across building designs. Adoption of 

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the ASHRAE 90.1-2001 design results in an increase in life-cycle costs for 8 of 9 building 

types and increases total life-cycle costs by $2.2 million. Adopting the ASHRAE 

90.1-2004 design results in a decrease in life-cycle costs for 5 of 9 building types, and 

increases total life-cycle costs by $128 730. Adopting the ASHRAE 90.1-2007 design 

results in a decrease in life-cycle costs for 6 of 9 building types, and decreases total 

life-cycle costs by $262 329. The LEC design decreases life-cycle costs for 4 of 9 

building types, and decreases total life-cycle costs by $389 675. For a 10-year study 

period, it is cost-effective overall to adopt the ASHRAE 90.1-2007 and LEC designs as 

Wyoming’s state energy code for commercial buildings. Assuming that the buildings 

considered in this study are generally representative of the entire new commercial 

building stock in the state, the results for the adoption of the ASHRAE 90.1-2001, 

ASHRAE 90.1-2004, ASHRAE 90.1-2007, and LEC design can be extrapolated to 

estimate statewide changes in life-cycle costs of $3.9 million, $225 446, -$459 421, 

and -$682 443 over the 10-year study period, respectively. 

Table 18-17 Statewide Change in Life-Cycle Costs for One Year of Construction, 

10-Year, Wyoming 

Building Subcategory m 2 ft2 Standard Edition 

Type Weighting (1000s) (1000s) 2001 2004 2007 LEC 

APART04 44.9 % 0 4 $1076 -$23 859 -$30 598 -$21 315
 

APART06 55.1 % 0 5 $410 -$29 785 -$35 740 -$23 168
 

HOTEL15 100.0 % 33 357 -$6885 -$507 760 -$399 523 -$291 730 

HIGHS02 100.0 % 51 547 $141 233 -$33 972 -$141 266 -$301 257 

OFFIC03 37.4 % 5 53 $595 478 $288 111 $258 801 $29 533 

OFFIC08 40.4 % 5 58 $677 748 $324 766 $290 883 $89 095 

OFFIC16 22.2 % 3 32 $90 -$69 818 -$27 727 $5726 

RETAIL1 100.0 % 32 339 $643 268 $66 718 -$222 013 $87 715 

RSTRNT1 100.0 % 2 19 $191 939 $114 327 $44 852 $35 726 

Total 131 1414 $2 244 356 $128 730 -$262 329 -$389 675 

Note: Dormitories are excluded because no such floor area category is reported in the construction data. 

18.3 State Summary 

Wyoming is one of three states in the West Census Region that have not yet adopted a 

state energy code for commercial buildings. On average, adopting ASHRAE 90.1-2007 

leads to reductions in energy use, energy costs, and cradle-to-grave energy-related carbon 

emissions, and does so in a life-cycle cost-effective manner. Based on the average annual 

new construction in the state from 2003 to 2007 and a 10-year study period, adopting 

ASHRAE 90.1-2007 as the state’s energy code for commercial buildings would lead to 

energy use savings of 34.9 GWh (119.3 GBtu), energy cost savings of $2.6 million, and 

22 866 metric tons of carbon emissions reductions while decreasing life-cycle costs by 

$459 421 for one year’s worth of commercial building construction. Adopting the LEC 

177
 
 

 

 

 

Wyoming 

design would be lead to even greater impacts than adopting ASHRAE 90.1-2007, with 

savings of 76.6 GWh (261.7 GBtu), $5.3 million of energy costs, and 45 279 metric tons 

of carbon emissions while decreasing life-cycle costs by $682 443 for one year’s worth of 

commercial building construction. 

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State Comparisons for the Adoption of the Low Energy Case Design 

19 State Comparisons for the Adoption of the Low Energy Case Design 

One purpose of this study is to determine which states could benefit the most from 

adopting a more stringent state energy code. This chapter analyzes benefits from the 

region-wide adoption of the LEC design relative to the current collection of state energy 

codes. The aggregate benefits and costs are compared for each of the states in the West 

Census Region. Benefits and costs on a percentage basis are also evaluated across several 

dimensions: geography (state and climate zone), time, and building type. As in the 

state-by-state analysis for analyzing benefits from adopting the LEC design, it is 

necessary to assume a particular study period length because energy costs and life-cycle 

costs fluctuate on an annual basis. A 10-year study period is used as the baseline because 

it is the most realistic investor time frame of the nine study period length options in 

BIRDS. The significance of the study period length will be tested below. 

It would be expected that the three states with no state energy code and the two states that 

have adopted ASHRAE 90.1-2001 would realize greater benefits from adopting the LEC 

design relative to the other eleven states in the West Census Region that have adopted the 

more energy efficient ASHRAE 90.1-2007. 

19.1 Total Savings Comparison 

By comparing the aggregate results from the detailed state-by-state analysis, some 

interesting trends emerge. Table 19-1 shows the total savings in energy use, energy costs, 

carbon emissions, and life-cycle costs from adopting the LEC design as the commercial 

building energy code for each of the states in the West Census Region for a 10-year study 

period. In general, there is a strong correlation between energy use with both energy costs 

and carbon emissions. However, there are a number of factors that lead to significant 

variation in relative savings, including current state energy code requirements, newly 

constructed building stock mix and size, climate zone, electricity costs, and electricity 

production fuel mix. 

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State Comparisons for the Adoption of the Low Energy Case Design 

Table 19-1 Total Reductions by State for Adoption of the LEC Design, 10-Year
 

Average Annual Energy Energy Carbon LCC 

State Code New Floor Area Use Costs (1000 tCO2e) ($million) 

1000 m2 (1000 ft2

) (GWh) ($million) 

AK 1999 290 (3116) 99.4 9.8 58.4 2.4 

AZ 1999 4758 (51 214) 1857.5 135.6 1254.7 79.1 

CA 2007 14 492 (155 996) 2543.2 305.6 1372.0 124.9 

CO 2001 3292 (35 437) 1112.9 72.7 1126.2 59.7 

HI 2004 536 (5773) 138.4 23.9 123.8 13.9 

ID 2007 802 (8629) 139.9 7.6 69.9 1.5 

MT 2007 238 (2562) 52.5 2.9 24.1 0.5 

NM 2007 817 (8790) 153.7 11.7 146.0 5.5 

NV 2004 3516 (37 844) 709.0 59.7 327.2 17.9 

OR 2007 1745 (18 788) 261.4 17.4 146.1 -0.4 

UT 2007 1718 (18 492) 286.6 18.8 144.3 5.4 

WA 2007 3710 (39 937) 525.0 32.3 266.7 -11.5 

WY 1999 230 (2477) 76.6 5.3 52.9 0.7 

Total 36 144 (389 056) 7956.1 703.3 4878.4 299.6 

Total energy use savings varies across states for a number of reasons. First, states with 

more newly constructed commercial floor area realize greater reductions in energy use. 

Second, states located in warmer climate zones realize greater reductions in energy use 

than the states located in colder climate zones because the buildings in warmer climates 

benefit more from the overhangs and daylighting installed in the LEC design. Third, a 

state’s current state energy code for commercial buildings drives variation in energy use 

across states. 

Consider the reductions in energy use for three states with similar amounts of new floor 

area: Colorado, Nevada, and Washington. Of these three states, Colorado realizes the 

greatest amount of total reductions in energy use (1112.9 GWh) followed by Nevada 

(709.0 GWh) and Washington (525.0 GWh). Even though Colorado has less new floor 

area construction than Nevada or Washington, it realizes greater total reductions because 

Colorado has adopted an older edition of ASHRAE 90.1 (-2001) as its state energy code 

than have Nevada (-2004) and Washington (-2007). 

Table 19-2 shows the 10-year reduction in energy use per unit of newly constructed floor 

area by state. The reduction in energy use per unit of floor area also is driven by the 

state’s adopted energy code for commercial buildings. The greatest reduction in energy 

use per unit of floor area resulting from adoption of the LEC design is realized by the 

four states that have no state energy code or have adopted ASHRAE 90.1-2001, ranging 

from 333 kWh/m2 (106 kBtu/ft2

) to 390 kWh/m2 (124 kBtu/ft2). The states that have 

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State Comparisons for the Adoption of the Low Energy Case Design 

adopted ASHRAE 90.1-2004 and -2007 realize reductions ranging from 141 kWh/m2 

(45 kBtu/ft2) to 258 kWh/m2 (82 kBtu/ft2). 

Table 19-2 Energy Use Reduction per Unit of Floor Area for Adoption of the LEC 

Design by State, 10-Year 

State Code 

Floor 

Area 

Ranking 

Average Annual 

New Floor Area 

1000 m2 (1000 ft2

) 

Energy Use Reduction 

GWh kWh/m2 kBtu/ft2 

AZ 1999 8 4758 (51 214) 1857.5 390 124 

AK 1999 46 290 (3116) 99.4 343 109 

CO 2001 17 3292 (35 437) 1112.9 338 107 

WY 1999 48 230 (2477) 76.6 333 106 

HI 2004 40 536 (5773) 138.4 258 82 

MT 2007 47 238 (2562) 52.5 221 70 

NV 2004 14 3516 (37 844) 709 202 64 

NM 2007 37 817 (8790) 153.7 188 60 

CA 2007 2 14 492 (155 996) 2543.2 175 56 

ID 2007 38 802 (8629) 139.9 175 56 

UT 2007 28 1718 (18 492) 286.6 167 53 

OR 2007 27 1745 (18 788) 261.4 150 48 

WA 2007 12 3710 (39 937) 525 141 45 

In general, the states that realize the greatest reductions in energy use also realize the 

greatest reductions in energy costs. However, reductions in energy costs are also 

impacted by the per unit energy costs of electricity and natural gas and the fuel mix of the 

reductions in energy use in a state. Table 19-3 shows each state’s reduction in energy 

costs per unit of reduction in energy use, natural gas rate, electricity rate, and the 

weighted average fraction of the reduction in electricity consumption offset by the change 

in natural gas consumption.42 States with the highest electricity rates tend to realize the 

greatest reductions in energy costs per unit of reduction in energy use. Relative to 

electricity prices, natural gas prices are fairly constant across states, excluding Hawaii, 

and are always cheaper per unit of energy. 

There is some fluctuation in the results due to the fuel source of the reductions in energy 

use. For example, Montana has a higher electricity rate than Utah, Wyoming, Oregon, 

and Colorado. However, Montana realizes a smaller average energy cost savings per unit 

of energy use savings ($0.06) than the other four states ($0.07 each) because Montana 

realizes a reduction in both electricity and natural gas consumption, which lowers the 

average reduction in energy costs. Meanwhile, the other four states realize a shift in fuel 

consumption from electricity to natural gas, leading to additional savings. 

42 The fraction of electricity offset by natural gas consumption is greater (less) than 100 % (-100 %) when 

natural gas consumption increases (decreases) by a greater amount than electricity consumption decreases. 

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State Comparisons for the Adoption of the Low Energy Case Design 

Table 19-3 Energy Cost Reduction per kWh of Energy Use Reduction for Adoption 

of the LEC Design by State, 10-Year 

State Code Offset 

(%) 

Electricity 

Rate 

(¢/kWh) 

Natural Gas 

Rate 

(¢/kWh) 

Energy Cost 

Reduction 

($/kWh) 

HI 2004 0.0 21.9 8.8 0.17 

CA 2007 13.0 13.4 2.3 0.12 

AK 1999 -24.9 14.5 2.8 0.10 

NV 2004 1.1 10.6 3.2 0.08 

NM 2007 16.0 8.4 2.2 0.08 

AZ 1999 2.2 9.4 3.6 0.07 

CO 2001 8.6 8.2 2.2 0.07 

OR 2007 18.8 7.5 3.5 0.07 

WY 1999 6.9 7.3 2.3 0.07 

UT 2007 21.7 7.0 2.2 0.07 

MT 2007 -38.9 8.3 2.8 0.06 

WA 2007 19.4 7.0 3.6 0.06 

ID 2007 8.4 6.5 2.9 0.05 

Table 19-4 shows the weighted average fraction of electricity consumption offset by a 

change in natural gas consumption, the average CO2 emission rate for electricity and 

natural gas, and the reduction in cradle-to-grave energy-related carbon emissions per unit 

of reduction in energy use for the thirteen states in this study. There is a direct correlation 

between the CO2 emissions rate for electricity generation in a state and the reduction in 

carbon emissions per unit of reduction in energy use. However, the correlation is not 

perfect. For example, Montana realizes smaller reductions in carbon emissions per unit of 

energy than Nevada, Idaho, Utah, Washington, and Oregon even though it has a greater 

electricity emissions rate. Montana realizes a reduction in both electricity and natural gas 

consumption, which lowers the average reduction in carbon emissions. Meanwhile, the 

other five states realize a shift in fuel consumption from electricity to natural gas, leading 

to additional savings. 

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State Comparisons for the Adoption of the Low Energy Case Design 

Table 19-4 Carbon Reduction per GWh of Energy Use Reduction for Adoption of 

the LEC Design by State, 10-Year 

State Code Offset 

(%) 

CO2e 

Emissions Rate 

for Electricity 

(t/GWh) 

CO2e 

Emissions Rate 

for Natural Gas 

(t/GWh) 

CO2e 

Reduction 

(t/GWh) 

CO 2001 8.6 994 241 1012 

NM 2007 16.0 835 241 950 

HI 2004 0.0 835 241 895 

WY 1999 6.9 661 241 690 

AZ 1999 2.2 801 241 675 

AK 1999 -24.9 663 241 588 

OR 2007 18.8 494 241 559 

CA 2007 13.0 497 241 539 

WA 2007 19.4 494 241 508 

UT 2007 21.7 494 241 503 

ID 2007 8.4 494 241 500 

NV 2004 1.1 494 241 461 

MT 2007 -38.9 573 241 459 

The relative change in life-cycle costs per unit of new floor area is shown in Table 19-5. 

There is some correlation between the energy use savings (Table 19-3) and the life-cycle 

cost-effectiveness of adopting the LEC design. However, the correlation is not perfect 

because in order to obtain energy use savings, additional construction costs are usually 

required. Eleven of thirteen Western states realize an average decrease in life-cycle costs 

from adoption of the LEC design, with the change in life-cycle costs ranging from 

$3.10/m2 ($0.29/ft2

) to -$25.92/m2 (-$2.41/ft2). There is not a strong correlation between 

the state energy code and the total statewide reduction in life-cycle costs per unit of floor 

area. 

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State Comparisons for the Adoption of the Low Energy Case Design 

Table 19-5 Life-Cycle Cost Reductions per Unit of New Floor Area for Adoption of 

the LEC Design by State, 10-Year 

State Code 

Floor 

Area 

Ranking 

kWh/m2 

LCC Reduction 

$million $/m2 $/ft2 

HI 2004 40 258 13.9 25.92 2.41 

CO 2001 17 338 59.7 18.13 1.68 

AZ 1999 8 390 79.1 16.62 1.54 

CA 2007 2 175 124.9 8.62 0.80 

AK 1999 46 343 2.4 8.29 0.77 

NM 2007 37 188 5.5 6.74 0.63 

NV 2004 14 202 17.9 5.09 0.47 

UT 2007 28 167 5.4 3.14 0.29 

WY 1999 48 333 0.7 3.04 0.28 

MT 2007 47 221 0.5 2.10 0.20 

ID 2007 38 175 1.5 1.87 0.17 

OR 2007 27 150 -0.4 -0.23 -0.02 

WA 2007 12 141 -11.5 -3.10 -0.29 

19.2 Percentage Change Comparison 

State comparisons are made based on the simple average changes for the cities analyzed 

in each state by building type.43 One building type is chosen to illustrate the detailed 

analysis possible with the powerful BIRDS database compiled for this study. Energy use, 

energy costs, energy-related carbon emissions, and life-cycle costs are analyzed for the 

most common existing building type, small office buildings. Summary results for the 

other 10 building types are reported in Table B-1 through Table B-10 in Appendix B. 

19.2.1 3-Story Office Building 

Table 19-6 summaries the percentage changes in energy use, energy costs, carbon 

emissions, and life-cycle costs from region-wide adoption of the LEC design for the 

3-story office building for a 10-year study period. On average, adoption of the LEC 

design for a 3-story office building decreases energy use, energy costs, and energyrelated carbon emissions by more than 24 % each while reducing life-cycle costs by 

2.9 %. 

43 City-level data is not available to weight by amount of building construction in each city. 

184
 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

State Comparisons for the Adoption of the Low Energy Case Design 

Table 19-6 Average Percentage Change by State from Region-wide Adoption of the 

LEC design, 3-Story Office Building, 10-Year 

Percentage Change 

State Energy Energy Carbon LCC 

Use Cost Emissions 

AK -25.5 -27.6 -26.9 -0.5 

AZ -34.7 -34.9 -35.0 -3.1 

CA -24.5 -25.5 -25.1 -3.0 

CO -29.3 -32.1 -32.4 -5.5 

HI -28.0 -28.0 -28.0 -5.7 

ID -19.7 -22.0 -22.1 -2.7 

MT -18.0 -20.1 -19.9 -1.9 

NM -23.3 -25.5 -25.6 -3.1 

NV -25.3 -26.7 -26.3 -4.3 

OR -21.2 -23.5 -23.6 -3.5 

UT -20.8 -24.6 -23.7 -3.0 

WA -19.6 -21.9 -22.4 -2.7 

WY -30.1 -31.8 -31.8 0.3 

Avg. -24.5 -26.3 -26.2 -2.9 

These detailed results can be readily analyzed in mappings of the West Census Region. 

Figure 19-1, Figure 19-2, Figure 19-3, and Figure 19-4, display the average percentage 

energy use savings, energy cost savings, carbon emissions reduction, and life-cycle cost 

savings by state, respectively. The states that have no state energy code or have adopted 

ASHRAE 90.1-2001 are shown with cross hatching and a bolded state border. Figure 19-1 

shows that the states that have not yet adopted ASHRAE 90.1-2007 realize the greatest 

reductions in energy use. Arizona and Wyoming, which have no state energy code, 

realize energy use savings greater than 30 % by adopting the LEC design. Alaska, 

Colorado, Nevada, and Hawaii realize reductions of 25 % to 30 %. None of the seven 

Western states that have adopted ASHRAE 90.1-2007 realize energy use savings of 

greater than 25 %. 

Figure 19-1 Average Energy Use Savings by State, 3-Story Office Building, 10-Year
 

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State Comparisons for the Adoption of the Low Energy Case Design 

Figure 19-2 shows the average energy cost savings over 10 years by state from adopting 

the LEC design. Every state reduces energy costs by at least 20 %. Two of the three states 

that have no state energy code and the only state that has adopted ASHRAE 90.1-2001 

realize energy cost savings of greater than 30 %. The remaining state with no energy code 

and the two states that have adopted ASHRAE 90.1-2004 realize energy cost savings of 

25 % to 30 %. Only two of the seven states that have adopted ASHRAE 90.1-2007 have 

energy cost savings greater than 25 %. 

Figure 19-2 Average Energy Cost Savings by State, 3-Story Office Building, 

10-Year 

Figure 19-3 shows the average reductions in energy-related carbon emissions by state 

from adopting the LEC design. Every state except for Montana realizes reductions in 

carbon emissions by at least 20 %. Similar to energy cost savings, the six states that have 

not yet adopted ASHRAE 90.1-2007 realize reductions in carbon emissions of greater 

than 25 %. Only two of the seven states that have adopted ASHRAE 90.1-2007 realize 

reductions greater than 25 %. 

Figure 19-3 Average Energy-related Carbon Emissions Reduction by State, 3-Story
 

Office Building, 10-Year
 

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State Comparisons for the Adoption of the Low Energy Case Design 

Figure 19-4 shows the average life-cycle cost savings over 10 years by state from 

adopting the LEC design. Two of the three states that have not adopted a state energy 

code realize increases in life-cycle costs. All three states that have adopted ASHRAE 

90.1-2001 or -2004 realize the greatest average percentage reductions in life-cycle costs. 

All states that have adopted ASHRAE 90.1-2007 realize percentage reductions life-cycle 

costs. 

Figure 19-4 Average Life-Cycle Cost Savings by State, 3-Story Office Building, 

10-Year 

For a 3-story office building, as expected, the states that have no state energy code or 

have adopted an older edition of ASHRAE 90.1 have the most to gain in percentage terms 

in energy use, energy cost, and carbon emissions savings from adopting the LEC design. 

However, the benefits realized by a state with no state energy code may not be life-cycle 

cost-effective. States that have adopted ASHRAE 90.1-2001, -2004, or -2007 would also 

realize significant benefits from the adoption of the LEC design for 3-story office 

buildings, and do so in a cost-effective manner. 

19.2.2 Region-wide Results by Study Period Length 

The analysis up to this point has focused on 3-story office buildings over a 10-year study 

period. It is important to consider how the study period length -- representing the time 

horizon of the investor -- impacts energy use, energy costs, energy-related carbon 

emissions, and life-cycle costs. Nine study period lengths are analyzed: 1 year, 5 years, 

10 years, 15 years, 20 years, 25 years, 30 years, 35 years, and 40 years. All building types 

are included in this analysis. 

Average reductions in energy use from adoption of the LEC design are constant over all 

study period lengths because energy efficiency is assumed to be constant over time. The 

regional reduction in average energy use across all 73 cities in the study ranges from 

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State Comparisons for the Adoption of the Low Energy Case Design 

10.5 % to 32.7 %, depending on the building type, with an overall regional average of 

18.5 %. Table 19-7 shows these results. 

Table 19-7 West Region Average Percentage Change in Energy Use by Building 

Type 

Building 

Type 

Percentage 

Change 

APART04 

APART06 

DORMI04 

DORMI06 

HOTEL15 

HIGHS02 

OFFIC03 

OFFIC08 

OFFIC16 

RETAIL1 

RSTRNT1 

Average 

-15.1 

-15.7 

-18.0 

-15.1 

-13.9 

-10.5 

-24.5 

-22.4 

-15.5 

-20.0 

-32.7 

-18.5 

As shown in Table 19-8, savings in energy costs vary slightly, in percentage terms, over 

increasing study period lengths. The regional average reduction in energy costs across all 

location-building type combinations ranges from 24.0 % for a 1-year study period to 

23.1 % for a 40-year study period. The minor variation within a building type is a result 

of some negative differential escalation rates used to adjust future energy prices, causing 

the percentage change in energy costs to decrease in magnitude as the study period 

lengthens. The regional average reduction ranges from 17.4 % to 37.3 %, depending on 

the building type, over all study periods. 

Table 19-8 West Region Average Percentage Change in Energy Costs by Building 

Type and Study Period Length 

Building Study Period Length 

Type 1 5 10 15 20 25 30 35 40 

APART04 -23.1 -23.0 -22.8 -22.6 -22.4 -22.3 -22.1 -22.0 -21.9 

APART06 -24.8 -24.6 -24.3 -24.1 -23.9 -23.8 -23.6 -23.5 -23.4 

DORMI04 -24.3 -24.2 -24.0 -23.9 -23.8 -23.6 -23.5 -23.4 -23.4 

DORMI06 -24.1 -24.0 -23.7 -23.5 -23.3 -23.2 -23.0 -22.9 -22.8 

HOTEL15 -20.7 -20.6 -20.4 -20.2 -20.1 -20.0 -19.9 -19.8 -19.7 

HIGHS02 -18.7 -18.6 -18.3 -18.1 -17.9 -17.8 -17.6 -17.5 -17.4 

OFFIC03 -26.4 -26.3 -26.3 -26.2 -26.2 -26.2 -26.1 -26.1 -26.1 

OFFIC08 -23.5 -23.5 -23.5 -23.5 -23.5 -23.4 -23.4 -23.4 -23.4 

OFFIC16 -18.6 -18.5 -18.5 -18.4 -18.3 -18.3 -18.2 -18.2 -18.2 

RETAIL1 -22.0 -21.9 -21.9 -21.8 -21.8 -21.8 -21.7 -21.7 -21.7 

RSTRNT1 -37.3 -37.2 -37.1 -37.0 -36.9 -36.8 -36.7 -36.7 -36.6 

Average -24.0 -23.9 -23.7 -23.6 -23.5 -23.4 -23.3 -23.2 -23.1 

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State Comparisons for the Adoption of the Low Energy Case Design 

Since the regional average reduction in energy use is constant over all study periods, the 

average energy-related carbon emissions reductions are also constant at 23.2 %. The 

regional average reduction in carbon emissions ranges from 17.5 % to 36.7 % depending 

on the building type, as shown in Table 19-9. 

Table 19-9 West Region Average Percentage Change in Carbon Emissions by 

Building Type 

Building Percentage 

Type Change 

APART04 -21.9 

APART06 -23.4 

DORMI04 -23.4 

DORMI06 -22.7 

HOTEL15 -19.7 

HIGHS02 -17.5 

OFFIC03 -26.2 

OFFIC08 -23.4 

OFFIC16 -18.2 

RETAIL1 -21.8 

RSTRNT1 -36.7 

Average -23.2 

Table 19-10 shows that the percentage changes in life-cycle costs vary significantly over 

increasing study period lengths, but on average decrease for all study period lengths. 

Seven of the 11 building types realize reductions in life-cycle costs for all study periods. 

Table 19-10 West Region Average Percentage Change in Life-Cycle Costs by 

Building Type and Study Period Length 

Building Study Period Length 

Type 1 5 10 15 20 25 30 35 40 

APART04 -2.1 -0.2 -0.1 -0.4 -0.2 -0.4 -0.5 -0.6 -0.5 

APART06 -0.2 0.0 -0.2 -0.6 -0.4 -0.6 -0.7 -0.9 -0.8 

DORMI04 -9.9 -2.2 -1.6 -1.8 -1.5 -1.6 -1.7 -1.7 -1.6 

DORMI06 0.3 -0.3 -0.6 -1.0 -0.9 -1.1 -1.2 -1.4 -1.3 

HOTEL15 1.2 0.3 -0.1 -0.6 -0.6 -0.8 -1.0 -1.2 -1.2 

HIGHS02 -2.5 -1.4 -1.2 -1.5 -1.4 -1.6 -1.7 -1.9 -1.8 

OFFIC03 -13.8 -3.7 -2.9 -3.1 -2.6 -2.8 -2.9 -3.0 -2.9 

OFFIC08 -4.7 -2.5 -2.4 -2.7 -2.4 -2.6 -2.7 -2.8 -2.7 

OFFIC16 1.8 0.8 0.4 -0.2 -0.2 -0.5 -0.7 -0.9 -0.9 

RETAIL1 -13.2 -0.6 -0.2 -0.6 -0.2 -0.4 -0.6 -0.8 -0.7 

RSTRNT1 -13.5 -4.7 -3.7 -4.3 -4.0 -4.3 -4.5 -4.6 -4.6 

Average -5.1 -1.3 -1.1 -1.5 -1.3 -1.5 -1.7 -1.8 -1.7 

Figure 19-5 shows that three building types – the 6-story dormitory, hotel, and 16-story 

office building – are not cost-effective for a 1-year study period, with an average change 

in life-cycle costs ranging from 0.3 % to 2.2 %. By a 15-year study period, all three 

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State Comparisons for the Adoption of the Low Energy Case Design 

building types become cost-effective. The 6-story apartment building is the only building 

type that is cost-effective at a 1-year study period and not cost-effective at a 5-year study 

period. However, the 6-story apartment building becomes cost-effective again by a 

10-year study period. 

2.0 

Change in Life-cycle Costs (%)
 

0.0 

-2.0 

-4.0 

-6.0 

-8.0 

-10.0 

-12.0 

-14.0 

1 5 10 15 20 25 30 35 40 

Study Period 

APART04 

APART06 

DORMI04 

DORMI06 

HOTEL15 

HIGHS02 

OFFIC03 

OFFIC08 

OFFIC16 

RETAIL1 

RSTRNT1 

Figure 19-5 Average Change in Life-Cycle Costs by Building Type and Study
 

Period Length
 

19.2.3 Region-wide Results by Building Type 

For a 10-year study period length, Table 19-11 shows the simple average changes across 

all 73 cities in the West Census Region, in percentage terms, from adopting the LEC 

design. The building types that realize the smallest percentage reductions in energy use, 

energy costs, and energy-related carbon emissions are the high school and hotel while the 

greatest reductions are realized by the restaurant, 3-story office building, and 8-story 

office building. The percentage changes in energy costs and carbon emissions are greater 

than the percentage changes in energy use. Ten of 11 building types realize reductions in 

life-cycle costs. The restaurant, 3-story office building, and 8-story office building realize 

the greatest percentage reductions in life-cycle costs. The 16-story office building realizes 

the only increase in life-cycle costs. 

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State Comparisons for the Adoption of the Low Energy Case Design 

Table 19-11 West Region Percentage Change for LEC by Building Type, 10-Year 

Building Percentage Change 

Type Energy Use Energy Cost Carbon LCC 

APART04 -15.1 -22.8 -21.9 -0.1 

APART06 -15.7 -24.3 -23.4 -0.2 

DORMI04 -18.0 -24.0 -23.4 -1.6 

DORMI06 -15.1 -23.7 -22.7 -0.6 

HOTEL15 -13.9 -20.4 -19.7 -0.1 

HIGHS02 -10.5 -18.3 -17.5 -1.2 

OFFIC03 -24.5 -26.3 -26.2 -2.9 

OFFIC08 -22.4 -23.5 -23.4 -2.4 

OFFIC16 -15.5 -18.5 -18.2 0.4 

RETAIL1 -20.0 -21.9 -21.8 -0.2 

RSTRNT1 -32.7 -37.1 -36.7 -3.7 

Average -18.5 -23.7 -23.2 -1.1 

19.2.4 Region-wide Results by Climate Zone 

Table 19-12 shows the region-wide average percentage change in energy use, energy 

costs, energy-related carbon emissions, and life-cycle costs by ASHRAE climate zone. 

These changes are for the adoption of the LEC design relative to current state energy 

codes for all building types combined. However, it is necessary to control for state energy 

codes to properly analyze these results. 

Table 19-12 Average Percentage Change for LEC by Climate Zone 

Climate Energy Energy Carbon LCC 

Zone Use Cost Emissions 

1 -23.1 -23.1 -23.9 -3.1 

2 -30.7 -30.9 -31.6 -2.8 

3 -20.2 -24.4 -23.4 -1.3 

4 -16.6 -21.3 -26.4 -0.7 

5 -17.8 -23.3 -23.4 -1.4 

6 -17.5 -23.0 -23.0 -0.7 

7 -23.1 -31.9 -29.0 -1.4 

8 -10.2 -23.4 -18.5 -0.6 

Average -18.5 -23.7 -23.9 -1.1 

Table 19-13 shows the average percentage reduction in energy use from adopting the 

LEC design for all cities located in a climate zone while controlling for state energy 

codes. The region-wide average reduction in energy use is 18.5 % with Zone 2 realizing 

the greatest reduction (30.7 %) followed by Zone 1 and Zone 7 (23.1 % each). 

Controlling for state energy codes, the warmer the climate the greater the reduction in 

energy use tends to be, which is a result of the energy efficiency improvement options 

191
 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

State Comparisons for the Adoption of the Low Energy Case Design 

(daylighting and overhangs) considered in the LEC design for cities located in Zone 1 

through Zone 5. 

Table 19-13 Average Percentage Change in Energy Use for LEC by Climate Zone 

and State Energy Code 

Climate Percentage Change 

Zone/Subzone 1999 2001 2004 2007 All 

1 -23.1 -23.1 

2 -39.2 -26.4 -30.7 

3 -21.3 -20.1 -20.2 

4 -31.0 -15.4 -16.6 

5 -30.4 -25.9 -17.1 -14.3 -17.8 

6 -23.8 -22.7 -13.3 -17.5 

7 -23.1 -23.1 

8 -10.2 -10.2 

Grand Total -22.8 -24.6 -20.0 -15.9 -18.5 

Table 19-14 shows the average percentage reduction in energy costs for all cities located 

in a climate zone while controlling for state energy codes. The region-wide average 

reduction in energy costs is 23.7 % with Zone 7 realizing the greatest average reduction 

in energy costs (31.9 %) and Zone 4 realizing the smallest reduction (21.3 %). Similar to 

energy use, after controlling for state energy codes, cities located in warmer climates tend 

to realize greater reductions in energy costs. 

Table 19-14 Average Percentage Change in Energy Costs for LEC by Climate Zone 

and State Energy Code 

Climate Percentage Change 

Zone/Subzone 1999 2001 2004 2007 All 

1 -23.1 -23.1 

2 -39.9 -26.4 -30.9 

3 -25.0 -24.3 -24.4 

4 -37.2 -20.0 -21.3 

5 -36.4 -35.7 -21.8 -18.8 -23.3 

6 -31.7 -33.2 -16.7 -23.0 

7 -31.9 -31.9 

8 -23.4 -23.4 

Grand Total -31.3 -34.7 -23.0 -20.1 -23.7 

Table 19-15 shows the average percentage reduction in energy-related carbon emissions 

for all cities located in a climate zone while controlling for state energy codes. Similar to 

energy use and energy costs, after controlling for state energy codes, cities located in 

192
 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

State Comparisons for the Adoption of the Low Energy Case Design 

warmer climates tend to realize greater reductions in the carbon emissions. However, 

there is some additional variation that is driven by a state’s average emissions rate. 

Table 19-15 Average Percentage Change in Carbon Emissions for LEC by Climate 

Zone and State Energy Code 

Climate Percentage Change 

Zone/Subzone 1999 2001 2004 2007 All 

1 -23.9 -23.9 

2 -40.3 -27.3 -31.6 

3 -24.5 -23.2 -23.4 

4 -38.7 -22.3 -26.4 

5 -37.9 -36.8 -21.5 -18.9 -23.4 

6 -31.5 -34.5 -16.4 -23.0 

7 -29.0 -29.0 

8 -18.5 -18.5 

Grand Total -29.8 -35.9 -23.1 -19.7 -23.9 

Table 19-16 shows the average percentage change in life-cycle costs for all cities located 

in a climate zone while controlling for state energy codes. Given the same state energy 

code, cities in warmer climates tend to realize greater percentage reductions in life-cycle 

costs. 

Table 19-16 Average Percentage Change in Life-Cycle Costs for LEC by Climate 

Zone and State Energy Code 

Climate Percentage Change 

Zone/Subzone 1999 2001 2004 2007 All 

1 -3.1 -3.1 

2 -2.9 -2.8 -2.8 

3 -1.2 -1.3 -1.3 

4 -1.5 -0.6 -0.7 

5 -1.6 -3.2 -1.6 -0.6 -1.4 

6 -0.5 -3.0 -0.3 -0.7 

7 -1.4 -1.4 

8 -0.6 -0.6 

Grand Total -1.0 -3.1 -2.0 -0.7 -1.1 

193
 
State Comparisons for the Adoption of the Low Energy Case Design 

194
 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Discussion 

20 Discussion 

This study analyzes the impacts of adopting new, more stringent state energy codes for 

73 cities located across the West Census Region. Results are summarized at the regional 

level as well as the state level for all thirteen Southern states. This section will discuss the 

key findings, limitations of the research, and recommended directions for future research. 

20.1 Key Findings 

Three states in the West Census Region have not yet adopted a state energy code for 

commercial buildings: Alaska, Arizona, and Wyoming. For all cities in Alaska and 

Wyoming and the cities in Arizona that have not adopted a local energy code, adoption of 

ASHRAE 90.1-2001 leads to reductions in energy use, energy costs, and energy-related 

carbon emissions, but not in a life-cycle cost-effective manner. In Arizona and Wyoming, 

ASHRAE 90.1-2004 leads to greater reductions in energy use, energy costs, and carbon 

emissions than ASHRAE 90.1-2001, and is life-cycle cost-effective to adopt. Alaska 

realizes an increase in energy use from adopting ASHRAE 90.1-2004 while decreasing 

energy costs, carbon emissions, and life-cycle costs. The shift in fuel consumption from 

electricity to natural gas allows energy use to increase while energy costs decrease. All 

three states realize reductions in energy use, energy costs, carbon emissions, and 

life-cycle costs from adopting ASHRAE 90.1-2007. 

Colorado is the only state in the West Census Region that has adopted ASHRAE 

90.1-2001 as its state energy code for commercial buildings. Colorado would realize 

reductions in energy use, energy costs, and energy-related carbon emissions as well as 

life-cycle costs from adopting ASHRAE 90.1-2004. Adopting ASHRAE 90.1-2007 would 

lead to greater reductions in energy use, energy costs, carbon emissions, and life-cycle 

costs than adopting ASHRAE 90.1-2004. 

Hawaii and Nevada are the states in the West Census Region that have adopted ASHRAE 

90.1-2004 as their state energy code for commercial buildings. Both states would realize 

cost-effective reductions in energy use, energy costs, and energy-related carbon 

emissions from adopting ASHRAE 90.1-2007. Nevada realizes greater total life-cycle cost 

savings than total energy cost savings because the relaxation of the window U-factor and 

SHGC requirements decreases total construction costs while still decreasing total energy 

use for the state. 

The adoption of the LEC design is analyzed for all thirteen states. The LEC design goes 

beyond ASHRAE 90.1-2007 by setting stricter building envelope requirements, lower 

lighting densities, and requiring daylighting controls as well as requiring overhangs for 

warmer climate zones. There are several factors that impact the percentage savings from 

adopting the LEC design for all states in the West Census Region, including the current 

195
 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Discussion 

state energy code, selected study period length, building type, and climate zone of the 

location. 

The region-wide adoption of the LEC design as the commercial building energy code for 

all building types significantly decreases energy use (18.5 %), energy costs (23.7 %), and 

carbon emissions (23.2 %), on average, while reducing life-cycle costs (1.1 %), on 

average, for a 10-year study period. Although the LEC design leads to reductions for all 

states, the magnitude of the reductions varies according to each state’s adopted energy 

code. The states that have not adopted ASHRAE 90.1-2007 realize the greatest percentage 

savings in energy use, energy costs, and carbon emissions. The states that have adopted 

ASHRAE 90.1-2004 realize the greatest percentage reductions in life-cycle costs. The 

states that have already adopted ASHRAE 90.1-2007 also realize percentage reductions in 

life-cycle costs. Two of the three states that have no state energy code realize an average 

percentage increase in life-cycle costs relative to ASHRAE 90.1-1999. 

The study period length impacts the resulting reductions in life-cycle costs. As the study 

period length increases from 5 years to 15 years, the number of building types that are 

cost-effective increases from eight to all eleven. The study period length is an important 

determinant of cost-effectiveness and size of the percentage changes in life-cycle costs. 

The climate zone of a location impacts the percentage reduction in energy use, energy 

costs, and carbon emissions. After controlling for each state’s energy code, cities located 

in warmer climates tend to realize greater average percentage reductions in these 

measures. 

Different building types realize different regional average percentage reductions in 

energy use, energy costs, and carbon emissions for a 10-year study period. High schools, 

16-story office buildings, and hotels realize the smallest reductions while restaurants and 

3-story office buildings realize the greatest reductions. The greatest percentage reductions 

in life-cycle costs are also realized by restaurants and 3- and 8-story office buildings 

while the only percentage increase is realized by 16-story office buildings. 

The magnitude of a building type’s average percentage change is not necessarily 

correlated with its changes in total energy use, energy costs, and energy-related carbon 

emissions relative to other building types. For example, high schools tend to realize some 

of the smallest percentage reductions, but some of the greatest total reductions in energy 

use, energy costs, and energy-related carbon emissions. Total reductions are driven 

largely by total new floor area constructed for the building type in a state. The adoption 

of the LEC design would lead to greater aggregate reductions in energy use in California 

than in Wyoming because the amount of newly constructed floor area for 2003 to 2007 

was 63 higher times in California. 

196
 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Discussion 

A number of other factors impact total reductions in energy use, energy costs, and carbon 

emissions: state energy codes, energy rates, and carbon emissions rates. The greatest 10­

year reductions in energy use per unit of floor area resulting from adoption of the LEC 

design are realized by the four states that have no state energy code or have adopted 

ASHRAE 90.1-2001, ranging from 333 kWh/m2 (106 kBtu/ft2) to 390 kWh/m2 

(124 kBtu/ft2). The states that have adopted ASHRAE 90.1-2004 or -2007 realize 

reductions ranging from 141 kWh/m2 (45 kBtu/ft2

) to 258 kWh/m2 (82 kBtu/ft2). States 

with the highest electricity rates tend to realize the largest reductions in energy costs per 

unit of energy consumption reduced. Similarly, states with higher CO2e emission rates 

per unit of electricity generated tend to realize greater reductions in emissions per unit of 

energy consumption reduced. The greater the offset of electricity consumption reductions 

with natural gas consumption increases, the greater the reduction in both energy costs and 

carbon emissions per unit of energy consumption reduced. 

20.2 Limitations and Future Research 

The use of building prototypes in this study is meant to reveal general trends in the 

benefits and costs of energy standard adoption at the city, state, and regional levels. The 

study is not appropriate for analysis of individual buildings because each building has 

specific characteristics that may differ from the prototype. The analysis in this study is 

limited in scope and would be strengthened by analyzing more states, including 

sensitivity analysis, expanding the BIRDS database and metrics, and enabling public 

access to all the results. 

This study only analyzes 13 of the 50 states in detail, and cannot be extrapolated to 

estimate the magnitude of nationwide savings. Combining the results in this study with 

detailed analysis of the remaining 37 states will allow for analysis of nationwide impacts. 

Also, extensive analysis across census regions may show some additional variation in 

results revealing insights not captured in this study. 

Sensitivity analysis is needed for at least two assumptions in the analysis. First, consider 

the assumed discount rate used in life-cycle costing. Although 3 % is a reasonable 

discount rate, in real terms, for federal government investment decisions, it may be too 

low of a value for an expected real return on an alternative investment in the private 

sector. A higher discount rate would decrease the value of future energy cost savings, 

which could impact the cost-effectiveness of adopting more energy efficient building 

designs. Sensitivity analysis on the assumed discount rate is needed to determine the 

robustness of the cost results. Second, the current analysis assumes that the cooling load 

is met by equipment running on electricity while heating loads are met with equipment 

running on natural gas, which is not the typical fuel mix for some areas of the nation. The 

database should be expanded to include alternative fuel sources for heating. 

197
 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Discussion 

Additional data are needed to refine and expand the BIRDS database. First, the study uses 

simple state averages of constructed floor area to summarize energy use, energy cost, 

carbon emissions, and life-cycle cost changes. However, the amount of total floor area 

constructed will vary significantly from city to city. Future research could develop a 

weighted average of savings in a state based on the fraction of newly constructed floor 

area by city. Second, the 11 prototypical buildings analyzed in this study are likely not 

representative of the entire building stock for each building type. For example, all 

high-rise buildings are not 100 % glazed, as assumed here. For this reason, the results 

should be considered as general magnitudes instead of hard numbers. Future research 

should include additional prototypes, such as the DOE Benchmark Buildings (NREL, 

2011), in the database. Additionally, since existing buildings account for nearly the entire 

building stock, prototypes for retrofitting buildings should be incorporated into the 

BIRDS database as well. Another addition to expand the database is the inclusion of 

building designs to meet the newest edition of ASHRAE 90.1 (-2010) as well as 

ASHRAE’s green building standard (ASHRAE 189.1-2011). The state average energy cost 

rates and energy-related carbon emissions rates do not control for local variation in 

energy tariffs or electricity fuel mixes. By using utility-level energy cost and emissions 

rate data, the accuracy of the estimates in BIRDS could be improved. Additionally, the 

fuel mix used for electricity generation across the United States will change over time as 

economic and regulatory conditions change. A range of potential emissions rates could be 

included to allow for potential changes in emissions rates in the future. 

The analysis in this study ignores the impacts that plug and process loads have on the 

reductions in energy use. Buildings with greater plug and process loads will realize 

smaller percentage changes in energy use because the energy efficiency measures 

considered in this study focus on the building envelope and HVAC equipment, holding 

constant the energy use from other equipment used in the building. As building energy 

efficiency improves, the plug and process loads become a larger fraction of the overall 

energy load. Future research should consider the impact changes in plug and process 

loads have on the overall energy use savings realized by energy efficiency improvements 

to buildings. 

This study only compares the current state energy code to newer, more stringent standard 

editions for states in the West Census Region. The BIRDS database is much more 

expansive, allowing researchers to compare any of the editions of ASHRAE 90.1 with any 

other edition of ASHRAE 90.1 or the LEC design for any state in the country. The BIRDS 

database should be made available to the public through a simple-to-use software tool 

that allows other researchers to use the database for their own research on building 

energy efficiency. 

Finally, a more comprehensive sustainability assessment of the benefits and costs of 

building energy efficiency would strengthen the impact of this work. This study applies 

198
 
 

 

 

 

 

 

 

 

Discussion 

environmental life cycle assessment methods to evaluate the global warming potentials 

attributable to building energy efficiency improvements. In a parallel effort, the BIRDS 

database is being expanded to include a full range of 11 life-cycle environmental impacts 

covering human health effects, ecological health effects, and resource depletion. The 

sustainability assessment is also being expanded beyond building energy efficiency to 

cover the materials used in construction, MRR, and waste management. The BIRDS 

software tool in development will provide the results of this more comprehensive 

sustainability assessment alongside the results summarized in this report. 

199
 
Discussion 

200
 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

References 

References 

ANSI/ASHRAE/USGBC/IES Standard 189.1-2011, Standard for the Design of HighPerformance Green Buildings, 2011, ASHRAE, Inc. and U.S. Green Building 

Council. 

ArcMap 10.1 software, ArcGIS desktop package, ESRI, Redlands, CA, 

http://www.esri.com/. 

ASHRAE/IESNA Standard Project Committee 90.1, ASHRAE 90.1-1999 

Standard- Energy Standard for Buildings Except Low-Rise Residential Buildings, 

1999, ASHRAE, Inc. 

ASHRAE/IESNA Standard Project Committee 90.1, ASHRAE 90.1-2001 

Standard- Energy Standard for Buildings Except Low-Rise Residential Buildings, 

2001, ASHRAE, Inc. 

ASHRAE/IESNA Standard Project Committee 90.1, ASHRAE 90.1-2004 

Standard- Energy Standard for Buildings Except Low-Rise Residential Buildings, 

2004, ASHRAE, Inc. 

ASHRAE/IESNA Standard Project Committee 90.1, ASHRAE 90.1-2007 

Standard- Energy Standard for Buildings Except Low-Rise Residential Buildings, 

2007, ASHRAE, Inc. 

ASHRAE/IESNA Standard Project Committee 90.1, ASHRAE 90.1-2010 

Standard- Energy Standard for Buildings Except Low-Rise Residential Buildings, 

2010, ASHRAE, Inc. 

ASTM International, ASTM Standards of Building Economics: 7th Edition, 2012. 

D.B. Belzer, K.A. Cort, D.W. Winiarski, E.E. Richman, Analysis of Potential Benefits 

and Costs of Adopting a Commercial Building Energy Standard in South Dakota, 

March 2005, Pacific Northwest National Laboratory, PNNL-15101. 

Commercial Buildings Energy Consumption Survey (CBECS) database, 2003, accessed 

June-July 2009, http://www.eia.doe.gov/emeu/cbecs/. 

Database of State Incentives for Renewables and Efficiency, Rules, Regulations, and 

Policies for Energy Efficiency database, building energy codes, accessed summer 

2010, www.dsireusa.org/. 

Department of Energy, 2009a, Building Technologies Program, EnergyPlus energy 

simulation software, http://apps1.eere.energy.gov/buildings/energyplus/. 

201
 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

References 

Department of Energy, 2009b, Building Technologies Program, State energy codes 

at-a-glance, http://www.energycodes.gov/states/maps/commercialStatus.stm. 

EnergyPlus Example File Generator, Building Energy Simulation Web Interface for 

EnergyPlus, accessed Feb. 2009, U.S. Department of Energy National Renewable 

Energy Laboratory, http://apps1.eere.energy.gov/buildings/energyplus/. 

Environmental Protection Agency, 2007 Emissions and Generation Integrated Database. 

S. Fuller, S. Petersen, Life-Cycle Costing Manual for the Federal Energy Management 

Program, 1996, NIST Handbook 135, 1995 Edition, U.S. Department of 

Commerce, Technology Administration and NIST. 

M.A. Halverson, K. Gowri, E.E. Richman, Analysis of Energy Savings Impacts of New 

Commercial Energy Codes for the Gulf Coast, December 2006, Pacific Northwest 

National Laboratory, PNNL-16282. 

J. Kneifel, Life-cycle Carbon and Cost Analysis of Energy Efficiency Measures in New 

Commercial Buildings, Energy and Buildings 42 (3) (2010) 333-340. 

J. Kneifel, 2011a, Beyond the Code: Energy, Carbon, and Cost Savings using 

Conventional Technologies, Energy and Buildings 43 (2011) 951-959. 

J. Kneifel, 2011b, Prototype Commercial Buildings for Energy and Sustainability 

Assessment: Whole Building Energy Simulation Design, September 2011, NIST, 

Technical Note 1716. 

J. Kneifel, 2012, Prototype Commercial Buildings for Energy and Sustainability 

Assessment: Design Specification, Life-Cycle Costing and Carbon Assessment, 

January 2012, NIST, Technical Note 1732. 

J. Kneifel, 2013, Benefits and Costs of Energy Standard Adoption in New Commercial 

Buildings, February 2013, NIST, Special Publication 1147. 

B. Lippiatt, Greig, A., Lavappa, P., Building for Environmental and Economic 

Sustainability (BEES) Online software, February 2011, NIST, 

http://ws680.nist.gov/bees/. 

National Oceanic and Atmospheric Administration, map of census regions, accessed Dec. 

2010, http://marineeconomics.noaa.gov/. 

National Renewable Energy Laboratory, 2011, U.S. Department of Energy Commercial 

Reference Building Models of the National Building Stock, TP-5500-46861. 

202
 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

References 

Pacific Northwest National Laboratory, 2009, Impacts of Standard 90.1-2007 for 

Commercial Buildings at State Level, United States Department of Energy 

Building Energy Codes Program. 

RS Means CostWorks databases, accessed 2009, http://www.meanscostworks.com/. 

A. Rushing, B. Lippiatt, Energy Price Indices and Discount Factors for Life-Cycle Cost 

Analysis-April 2008, May 2008, NIST, NISTIR 85-3273-23. 

M. Towers, R. Dotz, L. Romani, The Whitestone Building Maintenance and Repair Cost 

Reference 2008-2009, 13th Annual Edition, 2008, Whitestone Research. 

U.S. Energy Information Administration, 2010a, Electric power annual state data tables, 

Accessed 2010, http://www.eia.doe.gov/fuelelectric.html. 

U.S. Energy Information Administration, 2010b, Natural Gas Navigator, accessed 2010, 

http://www.eia.doe.gov/oil_gas/natural_gas/info_glance/natural_gas.html. 

U.S. Life-Cycle Inventory Database, 2012, http://www.nrel.gov/lci/. 

D. Winiarski, S. Shankle, J. Hail, B. Liu, A. Walker, The Business Case for Sustainable 

Design in Federal Facilities: Appendix B: Energy and Construction Cost 

Estimates, August 2003, Pacific Northwest National Laboratory and National 

Renewable Energy Laboratory. 

203
 
References 

204
 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Building and Energy Characteristics 

A Building and Energy Characteristics
 

Table A-1 CBECS Categories and Subcategories
 

Category Subcategory 

Education elementary or middle school 

high school 

college or university 

preschool or daycare 

adult education 

career or vocational training 

religious education 

Food Sales	 grocery store or food market 

gas station with a convenience 

store; 

convenience store 

Food Service fast food 

restaurant or cafeteria 

Health Care hospital 

Inpatient inpatient rehabilitation 

Health Care 

Outpatient 

Lodging 

Mercantile NonMall 

medical office (see previous 

column) 

clinic or other outpatient health 

care 

outpatient rehabilitation 

veterinarian 

motel or inn 

hotel 

dormitory, fraternity, or sorority 

retirement home 

nursing home, assisted living, etc. 

convent or monastery 

shelter, orphanage, halfway house 

retail store 

beer, wine, or liquor store 

rental center 

dealership or showroom for 

vehicles or boats 

studio/gallery 

Mercantile Malls enclosed mall 

strip shopping center 

Office administrative or professional 

office 

government office 

mixed-use office 

bank or other financial institution 

medical office (see previous 

column) 

sales office 

contractor's office 

non-profit or social services 

research and development 

city hall or city center 

religious office 

call center 

Category Subcategory 

Public	 social or meeting 

Assembly	 recreation 

entertainment or culture 

library 

funeral home 

student activities center 

armory 

exhibition hall 

broadcasting studio 

transportation terminal 

Public Order police station 

and Safety fire station 

jail, reformatory, or penitentiary 

courthouse or probation office 

Religious None 

Worship 

Service vehicle service or vehicle repair shop 

vehicle storage/ maintenance (car barn) 

repair shop 

dry cleaner or laundromat 

post office or postal center 

car wash 

gas station 

photo processing shop 

beauty parlor or barber shop 

tanning salon 

copy center or printing shop 

kennel 

Warehouse refrigerated warehouse 

and Storage non-refrigerated warehouse 

distribution or shipping center 

Other	 airplane hangar 

crematorium 

laboratory 

telephone switching 

agricultural with some retail space 

manufacturing or industrial with some 

retail space 

data center or server farm 

Vacant None 

205
 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Building and Energy Characteristics 

Table A-2 New Commercial Building Construction Volume for 2003 through 2007 

by State and Building Type 

State 

Building Construction Floor Area in 1000 m2 (1,000 ft2

) 

ApartmentHealthcareHotelOfficePublicAssembly

111 

(1190) 

RestaurantRetailSchoolWarehouseNoPrototype

259 

(2787) 

Total 

AK 19 (201) 130 

(1401) 

126 

(1357) 

226 

(2428) 13 (137) 208 (2240) 

231 

(2484) 

126 

(1356) 

1448 

(15 581) 

AZ 1043 

(11 223) 

1505 

(16 195) 

1047 

(11 272) 

4030 

(43 383) 

1180 

(12 701) 

271 

(2918) 

4891 

(52 646) 

2294 

(24 692) 

3721 

(40 052) 

3808 

(40 986) 

23 790 

(256 068) 

CA 9761 

(105 071) 

3310 

(35 633) 

3129 

(33 678) 

9219 

(99 228) 

3092 

(33 281) 

534 

(5747) 

10 623 

(114 344) 

7085 

(76 262) 

13 364 

(143 853) 

12345 

(132 882) 

72 462 

(779 978) 

CO 2033 

(21 885) 

1387 

(14 926) 

997 

(10 735) 

2158 

(23 225) 

708 

(7618) 

199 

(2142) 

2896 

(31 177) 

1654 

(17 804) 

1541 

(16582) 

2889 

(31 094) 

16461 

(177 186) 

HI 1280 

(13 773) 

91 (979) 92 (989) 171 

(1838) 

59 (630) 9 (95) 273 

(2939) 

92 (985) 132 

(1417) 

485 

(5220) 

2682 

(28 865) 

ID 233 

(2506) 

372 

(4001) 

221 

(2375) 

716 

(7703) 

230 

(2478) 

46 (493) 699 

(7526) 

636 

(6847) 

360 

(3876) 

496 

(5343) 

4008 

(43 147) 

MT 45 (481) 122 

(1313) 

118 

(1265) 

149 

(1602) 

94 

(1007) 

18 (195) 253 

(2723) 

174 

(1871) 

76 (821) 142 

(1533) 

1190 

(12 810) 

NM 89 (957) 247 

(2655) 

418 

(4499) 

617 

(6636) 

350 

(3770) 

62 (670) 765 

(8235) 

752 

(8097) 

292 

(3142) 

491 

(5290) 

4083 

(43 950) 

NV 2867 

(30 856) 

528 

(5684) 

2963 

(31 894) 

1626 

(17 504) 

1195 

(12 863) 

157 

(1691) 

2382 

(25 644) 

960 

(10 337) 

1669 

(17 969) 

3231 

(34 776) 

17 579 

(189 218) 

OR 1253 

(13 492) 

918 

(9885) 

360 

(3878) 

922 

(9927) 

383 

(4118) 

68 (728) 1382 

(14 881) 

651 

(7004) 

1142 

(12 291) 

1648 

(17 738) 

8727 

(93 941) 

UT 622 

(6695) 

569 

(6123) 

314 

(3384) 

1365 

(14 698) 

475 

(5110) 

76 (822) 1424 

(15 331) 

1269 

(13 657) 

1274 

(13 716) 

1201 

(12 926) 

8590 

(92 462) 

WA 3397 

(36 566) 

1085 

(11 683) 

871 

(9378) 

2435 

(26 209) 

833 

(8964) 

107 

(1147) 

2504 

(26 954) 

1841 

(19 817) 

1880 

(20 236) 

3598 

(38 731) 

18 551 

(199 685) 

WY 4 (42) 72 (774) 166 

(1787) 

66 (713) 127 

(1370) 

9 (97) 158 

(1696) 

254 

(2737) 

67 (718) 228 

(2453) 

1151 

(12387) 

Total 22 645 

(243 748) 

10 336 

(111 252) 

10 822 

(116 491) 

23 699 

(255 094) 

8835 

(95 100) 

1568 

(16 882) 

28 460 

(306 336) 

17 893 

(192 594) 

25 644 

(276 029) 

30 821 

(331 759) 

180 722 

(1 945 278) 

206
 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Building and Energy Characteristics 

Table A-3 

Type 

New Commercial Building Construction Share by State and Building 

Percentage of Building Construction Floor Area 

ApartmentHealthcareHotelOfficePublicAssemblyRestaurantRetailSchoolWarehouseNoPrototypeTotalRep. byStudy 

State 

AK 1.3 % 9.0 % 8.7 % 15.6 % 7.6 % 0.9 % 14.4 % 15.9 % 8.7 % 17.9 % 100.0 % 56.8 % 

AZ 4.4 % 6.3 % 4.4 % 16.9 % 5.0 % 1.1 % 20.6 % 9.6 % 15.6 % 16.0 % 100.0 % 57.1 % 

CA 13.5 % 4.6 % 4.3 % 12.7 % 4.3 % 0.7 % 14.7 % 9.8 % 18.4 % 17.0 % 100.0 % 55.7 % 

CO 12.4 % 8.4 % 6.1 % 13.1 % 4.3 % 1.2 % 17.6 % 10.0 % 9.4 % 17.5 % 100.0 % 60.4 % 

HI 47.7 % 3.4 % 3.4 % 6.4 % 2.2 % 0.3 % 10.2 % 3.4 % 4.9 % 18.1 % 100.0 % 71.4 % 

ID 5.8 % 9.3 % 5.5 % 17.9 % 5.7 % 1.1 % 17.4 % 15.9 % 9.0 % 12.4 % 100.0 % 63.6 % 

MT 3.8 % 10.2 % 9.9 % 12.5 % 7.9 % 1.5 % 21.3 % 14.6 % 6.4 % 12.0 % 100.0 % 63.5 % 

NM 2.2 % 6.0 % 10.2 % 15.1 % 8.6 % 1.5 % 18.7 % 18.4 % 7.1 % 12.0 % 100.0 % 66.2 % 

NV 16.3 % 3.0 % 16.9 % 9.3 % 6.8 % 0.9 % 13.6 % 5.5 % 9.5 % 18.4 % 100.0 % 62.3 % 

OR 14.4 % 10.5 % 4.1 % 10.6 % 4.4 % 0.8 % 15.8 % 7.5 % 13.1 % 18.9 % 100.0 % 53.1 % 

UT 7.2 % 6.6 % 3.7 % 15.9 % 5.5 % 0.9 % 16.6 % 14.8 % 14.8 % 14.0 % 100.0 % 59.0 % 

WA 18.3 % 5.9 % 4.7 % 13.1 % 4.5 % 0.6 % 13.5 % 9.9 % 10.1 % 19.4 % 100.0 % 60.1 % 

WY 0.3 % 6.2 % 14.4 % 5.8 % 11.1 % 0.8 % 13.7 % 22.1 % 5.8 % 19.8 % 100.0 % 57.1 % 

Table A-4 Electricity Generation CO2, CH4, and N2O Emissions Rates by State 

State CO2 CH4 N2O 

(t/GWh) (t/GWh) (t/GWh) 

AK 603.4 57.9 1.9 

AZ 746.9 53.2 1.2 

CA 450.0 45.8 1.5 

CO 938.8 54.0 0.8 

HI 807.1 28.0 0.1 

ID 465.6 27.6 0.4 

MT 542.8 30.1 0.4 

NM 778.5 55.3 1.3 

NV 465.6 27.6 0.4 

OR 465.6 27.6 0.4 

UT 465.6 27.6 0.4 

WA 465.6 27.6 0.4 

WY 623.7 36.4 0.5 

207
 
Building and Energy Characteristics 

208
 
 

 

 

 

 

 

 

 

 

 

Additional BIRDS Database Results 

B Additional BIRDS Database Results 

Table B-1 4-Story Apartment Building Summary Table for LEC and 10-Year 

Study Period 

Percentage Change State 

Energy Use Energy Cost Carbon LCC 

AK -12.7 -31.2 -25.0 -1.7 

AZ -26.6 -31.1 -32.4 -1.6 

CA -16.1 -22.5 -19.8 0.2 

CO -21.9 -36.2 -37.9 -1.2 

HI -20.4 -20.4 -20.4 -1.7 

ID -10.2 -14.8 -14.9 0.8 

MT -9.6 -15.2 -14.5 0.6 

NM -13.6 -20.0 -20.0 0.5 

NV -14.5 -20.7 -18.8 -0.1 

OR -10.0 -15.0 -15.4 1.1 

UT -10.7 -17.6 -15.7 0.7 

WA -8.8 -12.8 -14.0 1.2 

WY -22.7 -36.6 -36.4 -1.4 

Table B-2 6-Story Apartment Building Summary Table for LEC and 10-Year 

Study Period 

Percentage Change State 

Energy Use Energy Cost Carbon LCC 

AK -12.2 -31.1 -24.8 -1.5 

AZ -27.1 -32.5 -34.0 -1.7 

CA -18.2 -26.1 -22.8 -0.1 

CO -22.5 -37.7 -39.5 -1.2 

HI -20.7 -20.7 -20.7 -1.6 

ID -11.1 -16.5 -16.5 0.8 

MT -9.5 -15.1 -14.4 0.6 

NM -15.1 -23.0 -23.0 0.3 

NV -14.9 -22.9 -20.5 -0.1 

OR -10.9 -17.1 -17.7 1.0 

UT -11.9 -20.5 -18.2 0.6 

WA -9.4 -14.4 -15.8 1.2 

WY -22.5 -36.3 -36.2 -1.3 

209
 
 

 

 

 

 

 

 

Additional BIRDS Database Results 

Table B-3 4-Story Dormitory Summary Table for LEC and 10-Year Study Period
 

State Percentage Change 

Energy Use Energy Cost Carbon LCC 

AK -18.1 -34.8 -29.3 -2.4 

AZ -29.1 -32.1 -32.9 -1.6 

CA -18.2 -22.3 -20.6 -1.3 

CO -24.9 -36.6 -37.9 -4.2 

HI -22.1 -22.1 -22.1 -3.6 

ID -12.7 -16.4 -16.5 -1.2 

MT -12.9 -17.1 -16.6 -1.2 

NM -15.3 -19.8 -19.8 -1.6 

NV -17.1 -21.1 -19.9 -1.9 

OR -12.7 -16.7 -17.0 -1.0 

UT -12.8 -18.2 -16.8 -1.2 

WA -11.6 -15.0 -16.0 -0.5 

WY -26.9 -38.4 -38.3 -0.9 

Table B-4 6-Story Dormitory Summary Table for LEC and 10-Year Study Period
 

State Percentage Change 

Energy Use Energy Cost Carbon LCC 

AK -11.1 -30.0 -23.7 -2.2 

AZ -28.3 -33.6 -35.1 -2.4 

CA -17.9 -26.3 -22.7 -0.4 

CO -20.7 -36.0 -37.9 -1.8 

HI -23.0 -23.0 -23.0 -2.5 

ID -10.6 -15.6 -15.7 0.5 

MT -8.6 -13.6 -12.9 0.3 

NM -15.2 -22.8 -22.9 -0.1 

NV -14.1 -22.1 -19.6 -0.4 

OR -10.6 -16.7 -17.1 0.7 

UT -12.0 -20.1 -18.0 0.3 

WA -9.2 -14.1 -15.5 0.9 

WY -19.1 -33.4 -33.2 -1.8 

210
 
 

 

 

 

 

 

 

Additional BIRDS Database Results 

Table B-5 15-Story Hotel Building Summary Table for LEC and 10-Year Study 

Period 

Percentage Change State 

Energy Use Energy Cost Carbon LCC 

AK -6.9 -23.5 -18.0 -1.8 

AZ -23.1 -26.4 -27.3 -1.0 

CA -18.2 -24.5 -21.8 0.0 

CO -16.0 -28.8 -30.3 -1.1 

HI -18.0 -18.1 -18.1 -0.6 

ID -12.3 -15.9 -15.9 0.7 

MT -9.4 -11.5 -11.3 0.4 

NM -15.7 -21.1 -21.1 0.4 

NV -8.8 -14.7 -13.0 0.7 

OR -13.8 -18.4 -18.8 0.9 

UT -14.2 -20.2 -18.6 0.6 

WA -12.3 -16.2 -17.2 1.1 

WY -13.8 -24.7 -24.6 -1.3 

Table B-6 2-Story High School Summary Table for LEC and 10-Year Study 

Period 

Percentage Change State 

Energy Use Energy Cost Carbon LCC 

AK -7.7 -17.8 -14.0 -1.6 

AZ -21.5 -27.4 -29.2 -2.8 

CA -13.7 -23.4 -19.2 -1.8 

CO -10.6 -23.1 -25.0 -1.9 

HI -26.7 -26.7 -26.7 -4.2 

ID -6.0 -11.8 -11.9 -0.2 

MT -9.7 -13.9 -13.3 -0.6 

NM -9.6 -19.8 -19.9 -1.0 

NV -9.5 -18.2 -15.4 -1.5 

OR -4.9 -11.5 -12.1 0.0 

UT -5.9 -15.6 -12.8 -0.8 

WA -4.2 -9.4 -10.9 0.2 

WY -11.5 -21.2 -21.1 -1.3 

211
 
 

 

 

 

 

 

 

Additional BIRDS Database Results 

Table B-7 8-Story Office Building Summary Table for LEC and 10-Year Study 

Period 

Percentage Change State 

Energy Use Energy Cost Carbon LCC 

AK -21.3 -25.8 -24.6 0.0 

AZ -28.1 -28.0 -28.0 -2.3 

CA -21.4 -21.9 -21.8 -2.8 

CO -28.3 -29.7 -29.9 -5.1 

HI -21.3 -21.3 -21.3 -3.6 

ID -19.3 -20.4 -20.4 -2.4 

MT -16.9 -18.1 -18.0 -1.5 

NM -21.4 -22.5 -22.5 -2.8 

NV -23.0 -23.4 -23.3 -3.6 

OR -20.9 -22.0 -22.0 -3.0 

UT -20.7 -22.5 -22.1 -2.6 

WA -20.0 -21.1 -21.3 -2.3 

WY -29.2 -30.1 -30.0 0.7 

Table B-8 16-Story Office Building Summary Table for LEC and 10-Year Study 

Period 

Percentage Change State 

Energy Use Energy Cost Carbon LCC 

AK -8.1 -14.9 -12.9 -0.2 

AZ -19.6 -20.5 -20.8 0.0 

CA -19.8 -21.8 -21.0 -0.1 

CO -15.7 -21.2 -21.7 0.1 

HI -16.4 -16.4 -16.4 -0.6 

ID -15.3 -17.7 -17.8 0.9 

MT -11.7 -12.5 -12.5 0.4 

NM -18.9 -21.7 -21.7 0.3 

NV -12.5 -16.0 -15.1 0.7 

OR -17.8 -20.9 -21.1 1.0 

UT -17.5 -21.7 -20.8 0.6 

WA -16.2 -19.1 -19.8 1.4 

WY -12.8 -16.2 -16.1 0.1 

212
 
 

 

 

 

 

 

 

Additional BIRDS Database Results 

Table B-9 1-Story Retail Store Summary Table for LEC and 10-Year Study 

Period 

Percentage Change State 

Energy Use Energy Cost Carbon LCC 

AK -26.3 -27.3 -26.8 -0.2 

AZ -31.6 -32.4 -32.6 -1.8 

CA -16.1 -17.8 -17.1 0.0 

CO -28.4 -32.0 -32.4 -2.0 

HI -22.3 -22.3 -22.3 -3.1 

ID -14.2 -16.3 -16.3 1.2 

MT -16.0 -17.7 -17.5 0.1 

NM -15.6 -18.9 -18.9 0.1 

NV -21.0 -21.9 -21.7 -0.6 

OR -13.2 -15.3 -15.4 0.8 

UT -13.0 -17.3 -16.3 1.2 

WA -12.3 -13.9 -14.3 1.1 

WY -30.5 -34.0 -34.0 0.4 

Table B-10 1-Story Restaurant Summary Table for LEC and 10-Year Study 

Period 

Percentage Change State 

Energy Use Energy Cost Carbon LCC 

AK -33.4 -40.1 -37.9 1.0 

AZ -41.4 -43.6 -44.2 -5.2 

CA -34.1 -37.5 -36.2 -5.2 

CO -40.2 -46.3 -47.0 -7.4 

HI -34.8 -34.8 -34.8 -6.3 

ID -26.0 -30.8 -30.9 -2.7 

MT -24.1 -28.9 -28.4 -1.4 

NM -31.4 -36.6 -36.6 -4.3 

NV -35.1 -38.6 -37.7 -6.0 

OR -28.5 -33.0 -33.4 -4.5 

UT -27.1 -34.7 -32.9 -3.8 

WA -26.4 -30.6 -31.6 -3.9 

WY -42.3 -46.2 -46.1 1.3 

213