NIST Special Publication 1148-2 

Benefits and Costs of Energy 

Standard Adoption in New 

Commercial Buildings: Midwest 

Census Region 

Joshua Kneifel 

http://dx.doi.org/10.6028/NIST.SP.1148-2 

 

 

 

 

 

 

 

 

 

 

 

 

 

NIST Special Publication 1148-2 

Benefits and Costs of Energy 

Standard Adoption in New 

Commercial Buildings: Midwest 

Census Region 

Joshua Kneifel 

Applied Economics Office 

Engineering Laboratory 

http://dx.doi.org/10.6028/NIST.SP.1148-2 

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 1148-2
 

Natl. Inst. Stand. Technol. Spec. Publ. 1148-2, 195 pages (February 2013)
 

http://dx.doi.org/10.6028/NIST.SP.1148-2
 

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 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 costeffective 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 

Midwest 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. Kevin Teichman 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........................................................................................................ 11
 

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 Illinois....................................................................................................................... 21
 

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

6.1.1 Statewide Building Comparison ............................................................... 21
 

6.1.2 City Comparisons...................................................................................... 23
 

6.2 Total Savings...................................................................................................... 24
 

6.2.1 Energy Use ................................................................................................ 24
 

6.2.2 Energy Costs ............................................................................................. 26
 

6.2.3 Energy-related Carbon Emissions............................................................. 27
 

6.2.4 Life-Cycle Costs ....................................................................................... 28
 

6.3 State Summary ................................................................................................... 30
 

7 Indiana ..................................................................................................................... 31
 

7.1 Percentage Savings............................................................................................. 31
 

7.1.1 Statewide Building Comparison ............................................................... 31
 

7.1.2 City Comparisons...................................................................................... 33
 

7.2 Total Savings...................................................................................................... 34
 

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7.2.1 Energy Use ................................................................................................ 34
 

7.2.2 Energy Costs ............................................................................................. 36
 

7.2.3 Energy-related Carbon Emissions............................................................. 37
 

7.2.4 Life-Cycle Costs ....................................................................................... 38
 

7.3 State Summary ................................................................................................... 40
 

8 Iowa .......................................................................................................................... 41
 

8.1 Percentage Savings............................................................................................. 41
 

8.1.1 Statewide Building Comparison ............................................................... 41
 

8.1.2 City Comparisons...................................................................................... 43
 

8.2 Total Savings...................................................................................................... 44
 

8.2.1 Energy Use ................................................................................................ 44
 

8.2.2 Energy Costs ............................................................................................. 46
 

8.2.3 Energy-related Carbon Emissions............................................................. 47
 

8.2.4 Life-Cycle Costs ....................................................................................... 48
 

8.3 State Summary ................................................................................................... 50
 

9 Kansas ...................................................................................................................... 51
 

9.1 Percentage Savings............................................................................................. 51
 

9.1.1 Energy Use ................................................................................................ 52
 

9.1.2 Energy Costs ............................................................................................. 53
 

9.1.3 Energy-related Carbon Emissions............................................................. 53
 

9.1.4 Life-Cycle Costs ....................................................................................... 54
 

9.1.5 City Comparisons...................................................................................... 55
 

9.2 Total Savings...................................................................................................... 57
 

9.2.1 Energy Use ................................................................................................ 58
 

9.2.2 Energy Costs ............................................................................................. 59
 

9.2.3 Energy-related Carbon Emissions............................................................. 61
 

9.2.4 Life-Cycle Costs ....................................................................................... 62
 

9.3 State Summary ................................................................................................... 64
 

10 Michigan .................................................................................................................. 65
 

10.1 Percentage Savings............................................................................................. 65
 

10.1.1 Statewide Building Comparison .......................................................... 66
 

10.1.2 City Comparisons ................................................................................ 67
 

10.2 Total Savings...................................................................................................... 68
 

10.2.1 Energy Use .......................................................................................... 69
 

10.2.2 Energy Costs ........................................................................................ 70
 

10.2.3 Energy-related Carbon Emissions ....................................................... 72
 

10.2.4 Life-Cycle Costs .................................................................................. 73
 

10.3 State Summary ................................................................................................... 74
 

11 Minnesota................................................................................................................. 75
 

11.1 Percentage Savings............................................................................................. 75
 

11.1.1 Energy Use .......................................................................................... 76
 

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11.1.2 Energy Costs ........................................................................................ 76
 

11.1.3 Energy-related Carbon Emissions Reduction...................................... 77
 

11.1.4 Life-Cycle Costs .................................................................................. 78
 

11.1.5 City Comparisons ................................................................................ 79
 

11.2 Total Savings...................................................................................................... 81
 

11.2.1 Energy Use .......................................................................................... 82
 

11.2.2 Energy Costs ........................................................................................ 83
 

11.2.3 Energy-related Carbon Emissions ....................................................... 85
 

11.2.4 Life-Cycle Costs .................................................................................. 86
 

11.3 State Summary ................................................................................................... 88
 

12 Missouri ................................................................................................................... 89
 

12.1 Percentage Savings............................................................................................. 89
 

12.1.1 Energy Use .......................................................................................... 90
 

12.1.2 Energy Costs ........................................................................................ 91
 

12.1.3 Energy-related Carbon Emissions ....................................................... 91
 

12.1.4 Life-Cycle Costs .................................................................................. 92
 

12.1.5 City Comparisons ................................................................................ 93
 

12.2 Total Savings...................................................................................................... 95
 

12.2.1 Energy Use .......................................................................................... 95
 

12.2.2 Energy Costs ........................................................................................ 97
 

12.2.3 Energy-related Carbon Emissions ....................................................... 98
 

12.2.4 Life-Cycle Costs ................................................................................ 100
 

12.3 State Summary ................................................................................................. 101
 

13 Nebraska ................................................................................................................ 103
 

13.1 Percentage Savings........................................................................................... 103
 

13.1.1 Statewide Building Comparison ........................................................ 103
 

13.1.2 City Comparisons .............................................................................. 105
 

13.2 Total Savings.................................................................................................... 106
 

13.2.1 Energy Use ........................................................................................ 106
 

13.2.2 Energy Costs ...................................................................................... 108
 

13.2.3 Energy-related Carbon Emissions ..................................................... 109
 

13.2.4 Life-Cycle Costs ................................................................................ 110
 

13.3 State Summary ................................................................................................. 112
 

14 North Dakota ......................................................................................................... 113
 

14.1 Percentage Savings........................................................................................... 113
 

14.1.1 Energy Use ........................................................................................ 114
 

14.1.2 Energy Costs ...................................................................................... 115
 

14.1.3 Energy-related Carbon Emissions ..................................................... 116
 

14.1.4 Life-Cycle Costs ................................................................................ 116
 

14.1.5 City Comparisons .............................................................................. 117
 

14.2 Total Savings.................................................................................................... 119
 

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14.2.1 Energy Use ........................................................................................ 119
 

14.2.2 Energy Costs ...................................................................................... 121
 

14.2.3 Energy-related Carbon Emissions ..................................................... 123
 

14.2.4 Life-Cycle Costs ................................................................................ 124
 

14.3 State Summary ................................................................................................. 126
 

15 Ohio ........................................................................................................................ 129
 

15.1 Percentage Savings........................................................................................... 129
 

15.1.1 Statewide Building Comparison ........................................................ 129
 

15.1.2 City Comparisons .............................................................................. 131
 

15.2 Total Savings.................................................................................................... 132
 

15.2.1 Energy Use ........................................................................................ 132
 

15.2.2 Energy Costs ...................................................................................... 134
 

15.2.3 Energy-related Carbon Emissions ..................................................... 135
 

15.2.4 Life-Cycle Costs ................................................................................ 136
 

15.3 State Summary ................................................................................................. 138
 

16 South Dakota ......................................................................................................... 139
 

16.1 Percentage Savings........................................................................................... 139
 

16.1.1 Energy Use ........................................................................................ 140
 

16.1.2 Energy Costs ...................................................................................... 141
 

16.1.3 Energy-related Carbon Emissions ..................................................... 142
 

16.1.4 Life-Cycle Costs ................................................................................ 142
 

16.1.5 City Comparisons .............................................................................. 143
 

16.2 Total Savings.................................................................................................... 145
 

16.2.1 Energy Use ........................................................................................ 145
 

16.2.2 Energy Costs ...................................................................................... 147
 

16.2.3 Energy-related Carbon Emissions ..................................................... 148
 

16.2.4 Life-Cycle Costs ................................................................................ 150
 

16.3 State Summary ................................................................................................. 151
 

17 Wisconsin ............................................................................................................... 153
 

17.1 Percentage Savings........................................................................................... 153
 

17.1.1 Statewide Building Comparison ........................................................ 153
 

17.1.2 City Comparisons .............................................................................. 155
 

17.2 Total Savings.................................................................................................... 156
 

17.2.1 Energy Use ........................................................................................ 156
 

17.2.2 Energy Costs ...................................................................................... 157
 

17.2.3 Energy-related Carbon Emissions ..................................................... 159
 

17.2.4 Life-Cycle Costs ................................................................................ 160
 

17.3 State Summary ................................................................................................. 161
 

18 State Comparisons for the Adoption of the Low Energy Case Design ............ 163
 

18.1 Total Savings Comparison ............................................................................... 163
 

18.2 Percentage Savings Comparison ...................................................................... 168
 

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18.2.1 3-Story Office Building ..................................................................... 168
 

18.2.2 Region-wide Results by Study Period Length................................... 171
 

18.2.3 Region-wide Results by Building Type............................................. 174
 

18.2.4 Region-wide Results by Climate Zone .............................................. 175
 

19 Discussion............................................................................................................... 179
 

19.1 Key Findings .................................................................................................... 179
 

19.2 Limitations and Future Research...................................................................... 181
 

References ...................................................................................................................... 184
 

A Building and Energy Characteristics .................................................................. 188
 

B Additional BIRDS Database Results ................................................................... 192
 

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List of Figures 

Figure 2-1 Cities and Climate Zones ................................................................................. 7
 

Figure 18-1 Average Energy Use Savings by State, 3-Story Office Building,
 

10-Year ...................................................................................................... 169
 

Figure 18-2 Average Energy Cost Savings by State, 3-Story Office Building,
 

10-Year ...................................................................................................... 170
 

Figure 18-3 Average Energy-related Carbon Emissions Reduction by State, 3-Story
 

Office Building, 10-Year........................................................................... 170
 

Figure 18-4 Average Life-Cycle Cost Savings by State, 3-Story Office Building,
 

10-Year ...................................................................................................... 171
 

Figure 18-5 Average Change in Life-Cycle Costs by Building Type and Study
 

Period Length ............................................................................................ 174
 

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List of Tables 

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

Table 2-2 Energy Code by State/City for the Midwest 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 (Midwest, 2003 through 2007) ....... 16
 

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

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

Illinois.......................................................................................................... 21
 

Table 6-2 Average Percentage Change from Adoption of Newer Standard Editions,
 

10-Year, Illinois .......................................................................................... 22
 

Table 6-3 Average Percentage Change from Adoption of Newer Standard Editions
 

by City, 10-Year, Illinois............................................................................. 23
 

Table 6-4 Average Per Unit Change in Annual Energy Use, Illinois .............................. 25
 

Table 6-5 Statewide Change in Annual Energy Use for One Year of Construction,
 

Illinois.......................................................................................................... 26
 

Table 6-6 Average Per Unit Change in Energy Costs, 10-Year, Illinois ......................... 26
 

Table 6-7 Statewide Change in Energy Costs for One Year of Construction,
 

10-Year, Illinois .......................................................................................... 27
 

Table 6-8 Average Per Unit Change in Carbon Emissions, 10-Year, Illinois ................. 27
 

Table 6-9 Statewide Change in Total Carbon Emissions for One Year of
 

Construction, 10-Year, Illinois – Metric Tons ............................................ 28
 

Table 6-10 Average Per Unit Change in Life-Cycle Costs, 10-Year, Illinois ................. 29
 

Table 6-11 Statewide Change in Life-Cycle Costs for One Year of Construction,
 

10-Year, Illinois .......................................................................................... 30
 

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

Indiana ......................................................................................................... 31
 

Table 7-2 Average Percentage Change from Adoption of Newer Standard Editions,
 

10-Year, Indiana .......................................................................................... 32
 

Table 7-3 Average Percentage Change from Adoption of Newer Standard Editions
 

by City, 10-Year, Indiana ............................................................................ 33
 

Table 7-4 Average Per Unit Change in Annual Energy Use, Indiana ............................. 35
 

Table 7-5 Statewide Change in Annual Energy Use for One Year of Construction,
 

Indiana ......................................................................................................... 36
 

Table 7-6 Average Per Unit Change in Energy Costs, 10-Year, Indiana ........................ 36
 

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

10-Year, Indiana .......................................................................................... 37
 

Table 7-8 Average Per Unit Change in Carbon Emissions, 10-Year, Indiana ................ 37
 

Table 7-9 Statewide Change in Total Carbon Emissions for One Year of
 

Construction, 10-Year, Indiana – Metric Tons ........................................... 38
 

Table 7-10 Average Per Unit Change in Life-Cycle Costs, 10-Year, Indiana ................ 39
 

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

10-Year, Indiana .......................................................................................... 40
 

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

Iowa ............................................................................................................. 41
 

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

10-Year, Iowa .............................................................................................. 42
 

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

by City, 10-Year, Iowa ................................................................................ 43
 

Table 8-4 Average Per Unit Change in Annual Energy Use, Iowa ................................. 45
 

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

Iowa ............................................................................................................. 46
 

Table 8-6 Average Per Unit Change in Energy Costs, 10-Year, Iowa ............................ 46
 

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

10-Year, Iowa .............................................................................................. 47
 

Table 8-8 Average Per Unit Change in Carbon Emissions, 10-Year, Iowa .................... 47
 

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

Construction, 10-Year, Iowa – Metric Tons ............................................... 48
 

Table 8-10 Average Per Unit Change in Life-Cycle Costs, 10-Year, Iowa .................... 49
 

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

10-Year, Iowa .............................................................................................. 50
 

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

Kansas ......................................................................................................... 51
 

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

Standard Editions, Kansas ........................................................................... 52
 

Table 9-3 Average Percentage Change in Energy Costs, 10-Year, Kansas..................... 53
 

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

Year, Kansas................................................................................................ 54
 

Table 9-5 Average Percentage Change in Life-Cycle Costs, 10-Year, Kansas ............... 55
 

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

Standard Editions by City, Kansas .............................................................. 56
 

Table 9-7 Average Percentage Change in Energy Costs by City, 10-Year, Kansas........ 56
 

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

Kansas ......................................................................................................... 57
 

Table 9-9 Average Percentage Change in Life-Cycle Costs by City, 10-Year, Kansas .. 57
 

Table 9-10 Average Per Unit Change in Annual Energy Use, Kansas............................ 58
 

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

Kansas ......................................................................................................... 59
 

Table 9-12 Average Per Unit Change in Energy Costs, 10-Year, Kansas....................... 60
 

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

10-Year, Kansas .......................................................................................... 61
 

Table 9-14 Average Per Unit Change in Carbon Emissions, 10-Year, Kansas ............... 61
 

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

Construction, 10-Year, Kansas – Metric Tons ............................................ 62
 

Table 9-16 Average Per Unit Change in Life-Cycle Costs, 10-Year, Kansas ................. 63
 

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

10-Year, Kansas .......................................................................................... 64
 

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

Michigan...................................................................................................... 65
 

Table 10-2 Average Percentage Change from Adoption of the LEC Design, 10­

Year, Michigan ............................................................................................ 66
 

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Table 10-3 Average Percentage Change from Adoption of the LEC Design by City, 

10- Year, Michigan ..................................................................................... 68
 

Table 10-4 Average Per Unit Change in Annual Energy Use, Michigan ........................ 69
 

Table 10-5 Statewide Change in Annual Energy Use for One Year of Construction,
 

Michigan...................................................................................................... 70
 

Table 10-6 Average Per Unit Change in Energy Costs, 10-Year, Michigan ................... 71
 

Table 10-7 Statewide Change in Energy Costs for One Year of Construction,
 

10-Year, Michigan ...................................................................................... 71
 

Table 10-8 Average Per Unit Change in Carbon Emissions, 10-Year, Michigan ........... 72
 

Table 10-9 Statewide Change in Total Carbon Emissions for One Year of
 

Construction, 10-Year, Michigan – Metric Tons ........................................ 73
 

Table 10-10 Average Per Unit Change in Life-Cycle Costs, 10-Year, Michigan ........... 73
 

Table 10-11 Statewide Change in Life-Cycle Costs for One Year of Construction,
 

10-Year, Michigan ...................................................................................... 74
 

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

Minnesota .................................................................................................... 75
 

Table 11-2 Average Percentage Change in Energy Use from Adoption of Newer
 

Standard Editions, Minnesota ..................................................................... 76
 

Table 11-3 Average Percentage Change in Energy Costs, 10-Year, Minnesota ............. 77
 

Table 11-4 Average Percentage Change in Energy-related Carbon Emissions, 10­

Year, Minnesota .......................................................................................... 78
 

Table 11-5 Average Percentage Change in Life-Cycle Costs, 10-Year, Minnesota ....... 79
 

Table 11-6 Average Percentage Change in Energy Use from Adoption of Newer
 

Standard Editions by City, Minnesota......................................................... 80
 

Table 11-7 Average Percentage Change in Energy Costs by City, 10-Year,
 

Minnesota .................................................................................................... 80
 

Table 11-8 Average Percentage Change in Carbon Emissions by City, Minnesota........ 81
 

Table 11-9 Average Percentage Change in Life-Cycle Costs by City, 10-Year,
 

Minnesota .................................................................................................... 81
 

Table 11-10 Average Per Unit Change in Annual Energy Use, Minnesota .................... 82
 

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

Minnesota .................................................................................................... 83
 

Table 11-12 Average Per Unit Change in Energy Costs, 10-Year, Minnesota ............... 84
 

Table 11-13 Statewide Change in Energy Costs for One Year of Construction,
 

10-Year, Minnesota ..................................................................................... 85
 

Table 11-14 Average Per Unit Change in Carbon Emissions, 10-Year, Minnesota........ 85
 

Table 11-15 Statewide Change in Total Carbon Emissions for One Year of
 

Construction, 10-Year, Minnesota – Metric Tons....................................... 86
 

Table 11-16 Average Per Unit Change in Life-Cycle Costs, 10-Year, Minnesota.......... 87
 

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

10-Year, Minnesota ..................................................................................... 88
 

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

Missouri....................................................................................................... 89
 

Table 12-2 Average Percentage Change in Energy Use from Adoption of Newer
 

Standard Editions, Missouri ........................................................................ 90
 

Table 12-3 Average Percentage Change in Energy Costs, 10-Year, Missouri ................ 91
 

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Table 12-4 Average Percentage Change in Energy-related Carbon Emissions, 10­

Year, Missouri ............................................................................................. 92
 

Table 12-5 Average Percentage Change in Life-Cycle Costs, 10-Year, Missouri .......... 93
 

Table 12-6 Average Percentage Change in Energy Use from Adoption of Newer
 

Standard Editions by City, Missouri ........................................................... 93
 

Table 12-7 Average Percentage Change in Energy Costs by City, 10-Year, Missouri ... 94
 

Table 12-8 Average Percentage Change in Carbon Emissions by City, 10-Year,
 

Missouri....................................................................................................... 94
 

Table 12-9 Average Percentage Change in Life-Cycle Costs by City, 10-Year,
 

Missouri....................................................................................................... 95
 

Table 12-10 Average Per Unit Change in Annual Energy Use, Missouri ....................... 96
 

Table 12-11 Statewide Change in Annual Energy Use for One Year of Construction,
 

Missouri....................................................................................................... 96
 

Table 12-12 Average Per Unit Change in Energy Costs, 10-Year, Missouri .................. 97
 

Table 12-13 Statewide Change in Energy Costs for One Year of Construction,
 

10-Year, Missouri........................................................................................ 98
 

Table 12-14 Average Per Unit Change in Carbon Emissions, 10-Year, Missouri .......... 99
 

Table 12-15 Statewide Change in Total Carbon Emissions for One Year of
 

Construction, 10-Year, Missouri – Metric Tons ....................................... 100
 

Table 12-16 Average Per Unit Change in Life-Cycle Costs, 10-Year, Missouri .......... 100
 

Table 12-17 Statewide Change in Life-Cycle Costs for One Year of Construction,
 

10-Year, Missouri...................................................................................... 101
 

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

Nebraska .................................................................................................... 103
 

Table 13-2 Average Percentage Change from Adoption of the LEC Design, 10­

Year, Nebraska .......................................................................................... 104
 

Table 13-3 Average Percentage Change from Adoption of the LEC Design by City,
 

10-Year, Nebraska ..................................................................................... 105
 

Table 13-4 Average Per Unit Change in Annual Energy Use, Nebraska ...................... 107
 

Table 13-5 Statewide Change in Annual Energy Use for One Year of Construction,
 

Nebraska .................................................................................................... 108
 

Table 13-6 Average Per Unit Change in Energy Costs, 10-Year, Nebraska ................. 108
 

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

10-Year, Nebraska ..................................................................................... 109
 

Table 13-8 Average Per Unit Change in Carbon Emissions, 10-Year, Nebraska ......... 109
 

Table 13-9 Statewide Change in Total Carbon Emissions for One Year of
 

Construction, 10-Year, Nebraska – Metric Tons ...................................... 110
 

Table 13-10 Average Per Unit Change in Life-Cycle Costs, 10-Year, Nebraska ......... 111
 

Table 13-11 Statewide Change in Life-Cycle Costs for One Year of Construction,
 

10-Year, Nebraska ..................................................................................... 112
 

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

North Dakota ............................................................................................. 113
 

Table 14-2 Average Percentage Change in Energy Use from Adoption of Newer
 

Standard Editions, North Dakota .............................................................. 114
 

Table 14-3 Average Percentage Change in Energy Costs, 10-Year, North Dakota ...... 115
 

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Table 14-4 Average Percentage Change in Energy-related Carbon Emissions, 10­

Year, North Dakota ................................................................................... 116
 

Table 14-5 Average Percentage Change in Life-Cycle Costs, 10-Year, North Dakota 117
 

Table 14-6 Average Percentage Change in Energy Use from Adoption of Newer
 

Standard Editions by City, North Dakota.................................................. 118
 

Table 14-7 Average Percentage Change in Energy Costs by City, 10-Year, North
 

Dakota ....................................................................................................... 118
 

Table 14-8 Average Percentage Change in Carbon Emissions by City, 10-Year,
 

North Dakota ............................................................................................. 119
 

Table 14-9 Average Percentage Change in Life-Cycle Costs by City, 10-Year, North
 

Dakota ....................................................................................................... 119
 

Table 14-10 Average Per Unit Change in Annual Energy Use, North Dakota ............. 120
 

Table 14-11 Statewide Change in Annual Energy Use for One Year of Construction,
 

North Dakota ............................................................................................. 121
 

Table 14-12 Average Per Unit Change in Energy Costs, 10-Year, North Dakota ........ 122
 

Table 14-13 Statewide Change in Energy Costs for One Year of Construction,
 

10-Year, North Dakota .............................................................................. 123
 

Table 14-14 Average Per Unit Change in Carbon Emissions, 10-Year, North Dakota. 123
 

Table 14-15 Statewide Change in Total Carbon Emissions for One Year of
 

Construction, 10-Year, North Dakota – Metric Tons................................ 124
 

Table 14-16 Average Per Unit Change in Life-Cycle Costs, 10-Year, North Dakota... 125
 

Table 14-17 Statewide Change in Life-Cycle Costs for One Year of Construction,
 

10-Year, North Dakota .............................................................................. 126
 

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

Ohio ........................................................................................................... 129
 

Table 15-2 Average Percentage Change from Adoption of Newer Standard Editions,
 

10-Year, Ohio ............................................................................................ 130
 

Table 15-3 Average Percentage Change from Adoption of Newer Standard Editions
 

by City, 10-Year, Ohio .............................................................................. 131
 

Table 15-4 Average Per Unit Change in Annual Energy Use, Ohio ............................. 133
 

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

Ohio ........................................................................................................... 134
 

Table 15-6 Average Per Unit Change in Energy Costs, 10-Year, Ohio ........................ 134
 

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

10-Year, Ohio ............................................................................................ 135
 

Table 15-8 Average Per Unit Change in Carbon Emissions, 10-Year, Ohio ................ 135
 

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

Construction, 10-Year, Ohio – Metric Tons ............................................. 136
 

Table 15-10 Average Per Unit Change in Life-Cycle Costs, 10-Year, Ohio ................ 137
 

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

10-Year, Ohio ............................................................................................ 138
 

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

South Dakota ............................................................................................. 139
 

Table 16-2 Average Percentage Change in Energy Use from Adoption of Newer
 

Standard Editions, South Dakota .............................................................. 140
 

Table 16-3 Average Percentage Change in Energy Costs, 10-Year, South Dakota ...... 141
 

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Table 16-4 Average Percentage Change in Energy-related Carbon Emissions, 10­

Year, South Dakota ................................................................................... 142
 

Table 16-5 Average Percentage Change in Life-Cycle Costs, 10-Year, South Dakota 143
 

Table 16-6 Average Percentage Change in Energy Use from Adoption of Newer
 

Standard Editions by City, South Dakota.................................................. 143
 

Table 16-7 Average Percentage Change in Energy Costs by City, 10-Year, South
 

Dakota ....................................................................................................... 144
 

Table 16-8 Average Percentage Change in Carbon Emissions by City, 10-Year,
 

South Dakota ............................................................................................. 144
 

Table 16-9 Average Percentage Change in Life-Cycle Costs by City, 10-Year, South
 

Dakota ....................................................................................................... 145
 

Table 16-10 Average Per Unit Change in Annual Energy Use, South Dakota ............. 146
 

Table 16-11 Statewide Change in Annual Energy Use for One Year of Construction,
 

South Dakota ............................................................................................. 146
 

Table 16-12 Average Per Unit Change in Energy Costs, 10-Year, South Dakota ........ 147
 

Table 16-13 Statewide Change in Energy Costs for One Year of Construction,
 

10-Year, South Dakota .............................................................................. 148
 

Table 16-14 Average Per Unit Change in Carbon Emissions, 10-Year, South Dakota. 149
 

Table 16-15 Statewide Change in Total Carbon Emissions for One Year of
 

Construction, 10-Year, South Dakota – Metric Tons................................ 150
 

Table 16-16 Average Per Unit Change in Life-Cycle Costs, 10-Year, South Dakota... 150
 

Table 16-17 Statewide Change in Life-Cycle Costs for One Year of Construction,
 

10-Year, South Dakota .............................................................................. 151
 

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

Wisconsin .................................................................................................. 153
 

Table 17-2 Average Percentage Change from Adoption of the LEC design, 10-Year,
 

Wisconsin .................................................................................................. 154
 

Table 17-3 Average Percentage Change in Energy Use from Adoption of the LEC
 

Design by City, Wisconsin ........................................................................ 155
 

Table 17-4 Average Per Unit Change in Annual Energy Use, Wisconsin .................... 156
 

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

Wisconsin .................................................................................................. 157
 

Table 17-6 Average Per Unit Change in Energy Costs, 10-Year, Wisconsin ............... 158
 

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

10-Year, Wisconsin ................................................................................... 158
 

Table 17-8 Average Per Unit Change in Carbon Emissions, 10-Year, Wisconsin........ 159
 

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

Construction, 10-Year, Wisconsin – Metric Tons..................................... 160
 

Table 17-10 Average Per Unit Change in Life-Cycle Costs, 10-Year, Wisconsin........ 160
 

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

10-Year, Wisconsin ................................................................................... 161
 

Table 18-1 Total Reductions by State for Adoption of the LEC Design, 10-Year........ 164
 

Table 18-2 Energy Use Reduction per Unit of Floor Area for Adoption of the LEC
 

Design by State, 10-Year .......................................................................... 165
 

Table 18-3 Energy Cost Reduction per kWh of Energy Use Reduction for Adoption
 

of the LEC Design by State, 10-Year ........................................................ 166
 

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Table 18-4 Carbon Reduction per GWh of Energy Use Reduction for Adoption of 

the LEC Design by State, 10-Year ............................................................ 167 

Table 18-5 Life-Cycle Cost Reductions per Unit of New Floor Area for Adoption of 

the LEC Design by State, 10-Year ............................................................ 168 

Table 18-6 Average Percentage Change by State from Region-wide Adoption of the 

LEC design, 3-Story Office Building, 10-Year......................................... 169 

Table 18-7 Midwest Region Average Percentage Change in Energy Use by Building 

Type ........................................................................................................... 172 

Table 18-8 Midwest Region Average Percentage Change in Energy Costs by 

Building Type and Study Period Length ................................................... 172 

Table 18-9 Midwest Region Average Percentage Change in Carbon Emissions by 

Building Type............................................................................................ 173 

Table 18-10 Midwest Region Average Percentage Change in Life-Cycle Costs by 

Building Type and Study Period Length ................................................... 173 

Table 18-11 Midwest Region Percentage Change for LEC by Building Type, 

10-Year ...................................................................................................... 175 

Table 18-12 Average Percentage Change for LEC by Climate Zone............................ 176 

Table 18-13 Average Percentage Change in Energy Use for LEC by Climate Zone 

and State Energy Code .............................................................................. 176 

Table 18-14 Average Percentage Change in Energy Costs for LEC by Climate Zone 

and State Energy Code .............................................................................. 177 

Table 18-15 Average Percentage Change in Carbon Emissions for LEC by Climate 

Zone and State Energy Code ..................................................................... 177 

Table 18-16 Average Percentage Change in Life-Cycle Costs for LEC by Climate 

Zone and State Energy Code ..................................................................... 177 

Table A-1 CBECS Categories and Subcategories .......................................................... 188 

Table A-2 New Commercial Building Construction Floor Area for 2003 through 

2007 by State and Building Type .............................................................. 189 

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

Type ........................................................................................................... 190 

Table A-4 Electricity Generation CO2, CH4, and N2O Emissions Rates by State ......... 190 

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

Period ........................................................................................................ 192 

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

Period ........................................................................................................ 192 

Table B-3 4-Story Dormitory Summary Table for LEC and 10-Year Study Period ..... 193 

Table B-4 6-Story Dormitory Summary Table for LEC and 10-Year Study Period ..... 193 

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

Period ........................................................................................................ 193 

Table B-6 2-Story High School Summary Table for LEC and 10-Year Study Period 194 

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

Period ........................................................................................................ 194 

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

Period ........................................................................................................ 195 

Table B-9 1-Story Retail Store Summary Table for LEC and 10-Year Study Period . 195 

Table B-10 1-Story Restaurant Summary Table for LEC and 10-Year Study Period . 196
 

xxii
 
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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 twelve states in the Midwest 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. 

Four states in the Midwest Census Region have not yet adopted a state energy code for 

commercial buildings: Kansas, Missouri, North Dakota, and South Dakota. For these 

states, adoption of ASHRAE 90.1-2001 and -2004 lead to reductions in energy use, energy 

costs, and energy-related carbon emissions. However, adoption of ASHRAE 90.1-2001 is 

not life-cycle cost-effective in any of the four states because the additional costs from 

implementing the energy efficiency measures overwhelm the future energy cost savings. 

ASHRAE 90.1-2004 is not life-cycle cost-effective to adopt in three of the four states, 

with only South Dakota realizing a reduction in life-cycle costs. Adopting ASHRAE 

90.1-2007 leads to greater reductions in energy use, energy costs, and carbon emissions 

than ASHRAE 90.1-2001 or -2004, and is life-cycle cost-effective to adopt in three of the 

four states (Kansas is the exception). 

Minnesota is the only state in the Midwest Census Region that has adopted ASHRAE 

90.1-2004 as its state energy code for commercial buildings. Minnesota would realize 

reductions in energy use, energy costs, energy-related carbon emissions, and life-cycle 

costs from adopting ASHRAE 90.1-2007. 

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Executive Summary 

The adoption of the LEC design is analyzed for all twelve 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 Midwest 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 (16.1 %), energy costs (21.7 %), and 

carbon emissions (22.7 %), on average, while reducing life-cycle costs (0.7 %), 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 four states with no energy code realize the greatest percentage savings in 

energy use, energy costs, and carbon emissions. However, three of the four states realize 

percentage increases in life-cycle costs and the fourth state realizes a minimal percentage 

decrease. Meanwhile, the states that have already adopted ASHRAE 90.1-2007 realize 

reductions in life-cycle costs. 

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

period length increases from 5 years to 20 years, the number of building types that are 

cost-effective increases from 7 to all 11. The retail store is the only building type that is 

not cost-effective for all study periods longer than 10 years, and is cost-effective for all 

study period lengths of 20 years or greater. 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. There are no distinct trends in life-cycle costs associated with climate zones. 

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 

realize the smallest reductions while restaurants and 3- and 8-story office buildings 

realize the greatest reductions in energy use and energy costs. The reduction in carbon 

emissions is not perfectly correlated with reductions in energy use because along with the 

reduction in energy use, there is a change in the fuel source mix. The greatest percentage 

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

buildings while the smallest percentage reductions are realized by 16-story office 

buildings. 

xxvii
 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Executive Summary 

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 Illinois 

than in Iowa the amount of newly constructed floor area for 2003 to 2007 was almost five 

times greater in Illinois. 

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 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, ranging from 

404 kWh/m2 (128 kBtu/ft2

) to 456 kWh/m2 (145 kBtu/ft2), followed by the state that has 

adopted ASHRAE 90.1-2004 and realizes reductions of 351 kWh/m2 (111 kBtu/ft2). The 

states that have adopted ASHRAE 90.1-2007 realize reductions ranging from 168 kWh/m2 

(53 kBtu/ft2) to 206 kWh/m2 (65 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 fraction of the total reduction in energy use that is from electricity 

consumption, 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. 

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 

xxviii
 
 

 

 

Executive Summary 

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

located in the Midwest 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 Building 

Industry Reporting and Design for Sustainability (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 

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Introduction 

aggregated at the state level for seven states, Alaska, 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 BIRDS database to analyze the benefits and costs of increasing 

building energy efficiency for 58 cities located in the 12 states of the Midwest Census 

Region. BIRDS is a compilation of whole building energy simulations, building 

construction cost data, maintenance, repair, and replacement rates and costs, and energyrelated 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 

Midwest 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, 58 cities across the 

twelve states in the Midwest 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. 

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. 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 12 states in 

the Midwest Census Region.3 Four states currently do not have a statewide energy code 

while one state and 7 states have adopted ASHRAE 90.1-2004 and ASHRAE 90.1-2007, 

respectively. Two cities in the Midwest Census Region (St. Louis, MO and Huron, SD) 

have adopted newer editions of ASHRAE 90.1 than the state in which they are located. 

3 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 Midwest Census Region4 

State City Zone Code State City Zone Code State City Zone Code 

IA Burlington 5A 2007 MI Alpena 6A 2007 NE Grand Island 5A 2007 

Des Moines 5A 2007 Detroit 5A 2007 Norfolk 5A 2007 

Mason City 6A 2007 Flint 5A 2007 North Platte 5A 2007 

Sioux City 5A 2007 Grand Rapids 5A 2007 Omaha 5A 2007 

Waterloo 6A 2007 Houghton 7 2007 Scottsbluff 5A 2007 

IL Chicago 5A 2007 Lansing 5A 2007 OH Akron 5A 2007 

Moline 5A 2007 Muskegon 5A 2007 Cleveland 5A 2007 

Peoria 5A 2007 Sault Sainte Marie 7 2007 Columbus 5A 2007 

Rockford 5A 2007 Traverse City 6A 2007 Mansfield 5A 2007 

Springfield 5A 2007 MN Duluth 7 2004 Toledo 5A 2007 

IN Evansville 4A 2007 International Falls 7 2004 Youngstown 5A 2007 

Fort Wayne 5A 2007 Minneapolis 6A 2004 SD Huron 6A 2001 

Indianapolis 5A 2007 Rochester 6A 2004 Pierre 6A None 

South Bend 5A 2007 Saint Cloud 6A 2004 Sioux Falls 6A None 

KS Dodge City 4A None MO Columbia 4A None WI Eau Claire 6A 2007 

Goodland 5A None Kansas City 4A None Green Bay 6A 2007 

Topeka 4A None St. Louis 4A 2001 La Crosse 6A 2007 

Wichita 4A None Springfield 4A None Madison 6A 2007 

ND Bismarck 6A None Milwaukee 6A 2007 

Fargo 7 None 

Minot 7 None 

The 12 states, 58 cities, and ASHRAE climate zones listed in Table 2-2 are shown in 

Figure 2-1. States with more significant population centers have more cities included in 

the BIRDS database. For example, Michigan has 9 cities while South Dakota has 3 cities. 

The climate zone(s) for each state vary across the Midwest Census Region from ASHRAE 

Climate Zone 4 in Springfield, Missouri to Climate Zone 7 in Houghton, Michigan. 

Figure 2-1 Cities and Climate Zones 

4 State energy codes as of December 2011. 

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Study Design 

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).5 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. 

5 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.6 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.7 

Table 3-2 summarizes the HVAC efficiency requirements for each building design option 

across the different types of HVAC equipment.8 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. 

6 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). 

7 Overhang cost source is Winiarski et al. (2003) 

8 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. 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. 

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 

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Cost Data 

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 

study period to the service life of the building, and discounted from the end of the study 

period. 

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Cost Data 

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).9 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. 

9 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 2003Commercial 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 46.5 % of new commercial 

building stock floor area for 2003 through 2007 for the Midwest 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 57.8 % of the new commercial building stock. 

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2007)

Building Stock Data 

Table 4-1 New Commercial Building Construction (Midwest, 2003 through 2007) 

Category Subcategory 

Conditioned Floor 

Area 

1000 m2 (1000 ft2

) 

Percentage in 

Category 

Percentage 

of Total 

Office Large 3632 (39 100) 22.2 % 2.5 % 

Office Medium 6610 (71 155) 40.4 % 4.5 % 

Office Small 6120 (65 871) 37.4 % 4.1 % 

Retail 20 974 (225 765) 72.9 % 14.2 % 

Strip Mall 7797 (83 927) 27.1 % 5.3 % 

School Primary 6 215 (66 898) 32.5 % 4.2 % 

School Secondary 12 908 (138 941) 67.5 % 8.7 % 

Hospital 5769 (62 093) 44.1 % 3.9 % 

Other Health Care 7312 (78 708) 55.9 % 5.0 % 

Restaurant Sit Down 903 (9725) 52.9 % 0.6 % 

Restaurant Fast Food 804 (8658) 47.1 % 0.5 % 

Hotel Large 5190 (55 862) 74.2 % 3.5 % 

Hotel/Motel Small 1805 (19 424) 25.8 % 1.2 % 

Warehouse 18 614 (200 364) 12.6 % 

Public Assembly 9238 (99 434) 6.3 % 

Apartment High-rise 6816 (73 370) 55.1 % 4.6 % 

Apartment Mid-rise 5554 (59 788) 44.9 % 3.8 % 

No Prototype 21 286 (229 124) 14.4 % 

Total (2003 to 147 549 (1 588 205) 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.10 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. 

10 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.11 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 (MBtu) 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).12 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.13 

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 

11 For states located in more than one NERC sub-region, a weighted average of emissions rates for the
 

multiple sub-regions is implemented.
 

12 Emissions rates are held constant over all study periods.
 13 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.
 

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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. 

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6 

Illinois 

Illinois 

Illinois has adopted ASHRAE 90.1-2007 as its state energy code for commercial 

buildings, is located in the East North Central Census Division, and spans two climate 

zones (Zone 4A and Zone 5A). Table 6-1 provides an overview of Illinois’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 87 kWh/m2 to 106 kWh/m2 (28 kBtu/ft2 to 34 kBtu/ft2

) annually. The high 

school uses the greatest amount of energy at 242 kWh/m2 to 257 kWh/m2 (77 kBtu/ ft2 to 

81 kBtu/ft2

) annually. 

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

Illinois 

Building 

Type 

Standard Edition 

2007 

kWh/m2 kBtu/ft2 

LEC 

kWh/m2 kBtu/ft2 

APART04 

APART06 

173 55 

171 54 

156 50 

153 49 

DORMI04 

DORMI06 

134 42 

189 60 

119 38 

170 54 

HOTEL15 179 57 158 50 

HIGHS02 257 81 242 77 

OFFIC03 

OFFIC08 

OFFIC16 

117 37 

106 34 

168 53 

97 31 

87 28 

145 46 

RETAIL1 130 41 114 36 

RSTRNT1 179 57 137 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. 

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 the LEC design in the state of Illinois. 

6.1.1 Statewide Building Comparison 

Table 6-2 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. 

21
 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Illinois 

There is significant variation in the change in energy use for the LEC design relative to 

ASHRAE 90.1-2007, ranging from -5.6 % to -23.3 % depending on the building type with 

an overall average of -13.1 %. High schools realize the lowest reductions in energy use 

while restaurants realize the greatest reductions in energy use. 

Table 6-2 Average Percentage Change from Adoption of Newer Standard Editions, 

10-Year, Illinois 

Building LEC 

Type Energy Use Energy Cost Carbon LCC 

APART04 -9.4 -17.1 -17.1 0.3 

APART06 -10.5 -20.0 -20.1 0.1 

DORMI04 -11.1 -17.8 -17.8 -0.3 

DORMI06 -10.3 -19.4 -19.4 -0.2 

HOTEL15 -11.8 -19.2 -19.2 0.2 

HIGHS02 -5.6 -16.4 -16.5 -1.1 

OFFIC03 -17.5 -23.0 -23.0 -2.4 

OFFIC08 -17.8 -21.0 -21.0 -2.2 

OFFIC16 -13.9 -19.8 -19.8 0.2 

RETAIL1 -12.5 -16.9 -16.9 -0.4 

RSTRNT1 -23.3 -32.6 -32.6 -4.5 

Average -13.1 -20.3 -20.3 -0.9 

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 -16.4 % to -32.6 % depending 

on the building type with an average of -20.3 % 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 8 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 

41.9 % of the reduction in electricity consumption, and results in a percentage reduction 

in energy costs that is nearly three 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 change in energy-related carbon emissions 

across building types for the LEC design relative to ASHRAE 90.1-2007, ranging 

from -16.5 % to -32.6 % with an average of -20.3 %. 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 

22
 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Illinois 

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 8 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 -4.5 % to 0.3 % for a 10-year study period. Seven of the 11 building types realize 

reductions in life-cycle costs. Based on the overall average percentage reduction in lifecycle costs of 0.9 %, the LEC design may be cost-effective if the state adopted it as its 

state energy code for commercial buildings. 

6.1.2 City Comparisons 

Simulations are run for five cities located in Illinois, all located in Zone 5A: Chicago, 

Moline, Peoria, Rockford, and Springfield. While the five 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 6-3 shows the percentage change in energy use, energy costs, energy-related 

carbon emissions, and life-cycle costs for adoption of 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 do not vary significantly across 

cities, ranging from -12.7 % to -13.9 % with an overall average of -13.1 %. Any variation 

in local climate appears to have minimal effects on energy consumption. 

Table 6-3 Average Percentage Change from Adoption of Newer Standard Editions 

by City, 10-Year, Illinois 

Cities Zone LEC 

Energy Use Energy Cost Carbon LCC 

Chicago 5A -12.7 -20.1 -20.3 -0.6 

Moline 5A -13.3 -20.4 -20.7 -0.9 

Peoria 5A -13.1 -20.3 -20.5 -0.8 

Rockford 5A -12.4 -20.0 -20.3 -0.8 

Springfield 5A -13.9 -20.7 -20.9 -1.5 

Average -13.1 -20.3 -20.6 -0.9 

23
 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Illinois 

The average percentage change in energy costs for all building types also varies 

minimally across cities, ranging from -20.0 % to -20.7 % 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 minimally across all cities, ranging 

from -20.3 % to -20.9 %. Reductions in life-cycle costs vary across building types, with 

the percentage change in life-cycle costs ranging from -0.6 % to -1.5 %. Springfield 

realizes much larger reductions in life-cycle costs than the other 4 cities. 

6.2 Total Savings 

How much can Illinois 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 6-4 reports the average per unit change in annual energy use by building type and 

building design in the state.14 The reduction per m2 (ft2

) is multiplied by the estimated m2 

(ft2) of new construction of each building type, and Table 6-5 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.15 

14 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.
 

15 State-level subcategory data are not available.
 

24
 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Illinois 

Table 6-4 Average Per Unit Change in Annual Energy Use, Illinois
 

Building Standard Edition 

Type LEC 

kWh/m2 kBtu/ft2 

APART04 -17.5 -5.5 

APART06 -16.8 -5.3 

DORMI04 -17.6 -5.6 

DORMI06 -16.7 -5.3 

HOTEL15 -17.8 -5.6 

HIGHS02 -21.6 -6.9 

OFFIC03 -17.5 -5.6 

OFFIC08 -18.0 -5.7 

OFFIC16 -20.2 -6.4 

RETAIL1 -22.0 -7.0 

RSTRNT1 -44.0 -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 71.8 GWh (245.1 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 59.2 % 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 121.3 GWh (414.1 GBtu) per year. These savings imply 1212.7 GWh (4140.6 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 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 greatest 

total reductions are realized by retail stores and 6-story apartments because they represent 

27.6 % and 19.6 %, respectively, of the new construction in the state while all other 

building types represent 16.0 % 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 6-story 

apartment buildings -- only rank 5th and 8th in percentage reduction, respectively, among 

the 11 building types, as reported in Table 6-2. 

25
 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Illinois 

Table 6-5 Statewide Change in Annual Energy Use for One Year of Construction, 

Illinois 

Building Subcategory m 2 ft2 Standard Edition 

Type Weighting (1000s) (1000s) LEC 

kWh kBtu 

APART04 44.9 % 656.5 7066 -10 695 560 -36 519 240
 

APART06 55.1 % 804.1 8655 -14 477 986 -49 434 069
 

HOTEL15 100.0 % 260.8 2807 -5 503 035 -18 789 727 

HIGHS02 100.0 % 616.5 6636 -8 830 677 -30 151 730 

OFFIC03 37.4 % 219.3 2361 -4 495 869 -15 350 829 

OFFIC08 40.4 % 236.5 2546 -4 462 289 -15 236 174 

OFFIC16 22.2 % 130.2 1401 -3 036 937 -10 369 408 

RETAIL1 100.0 % 1132.1 12 186 -18 360 017 -62 688 994 

RSTRNT1 100.0 % 46.4 499 -1 928 277 -6 583 968 

Total 4102.5 44 159 -71 790 647 -245 124 139 

Note: Dormitories are excluded because no such floor area category is reported 

in the construction data. 

6.2.2 Energy Costs 

Table 6-6 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 6-6 Average Per Unit Change in Energy Costs, 10-Year, Illinois 

Building Standard Edition 

Type LEC 

$/m2 $/ft2 

APART04 -$16.11 -$1.50 

APART06 -$19.02 -$1.77 

DORMI04 -$13.27 -$1.23 

DORMI06 -$20.25 -$1.88 

HOTEL15 -$19.09 -$1.77 

HIGHS02 -$20.03 -$1.86 

OFFIC03 -$20.35 -$1.89 

OFFIC08 -$17.99 -$1.67 

OFFIC16 -$22.92 -$2.13 

RETAIL1 -$14.83 -$1.38 

RSTRNT1 -$38.88 -$3.61 

Table 6-7 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 $73.6 million for 10 years of building operation. 

26
 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Illinois 

Assuming that the buildings considered in this study, which represent 59.2 % 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 $124.4 million over the 10-year 

study period. 

Table 6-7 Statewide Change in Energy Costs for One Year of Construction, 

10-Year, Illinois 

Building Subcategory m 2 ft2 Standard Edition
 

Type Weighting (1000s) (1000s) LEC
 

APART04 44.9 % 656.5 7066 -$10 574 507 

APART06 55.1 % 804.1 8655 -$15 294 462 

HOTEL15 100.0 % 260.8 2807 -$4 979 630 

HIGHS02 100.0 % 616.5 6636 -$12 543 163 

OFFIC03 37.4 % 219.3 2361 -$4 392 912 

OFFIC08 40.4 % 236.5 2546 -$4 256 760 

OFFIC16 22.2 % 130.2 1401 -$2 982 916 

RETAIL1 100.0 % 1132.1 12 186 -$16 788 997 

RSTRNT1 100.0 % 46.4 499 -$1 803 993 

Total 4102.5 44 159 -$73 617 341 

Note: Dormitories are excluded because no such floor area category 

is reported in the construction data. 

6.2.3 Energy-related Carbon Emissions 

Table 6-8 reports the average energy-related carbon emissions reduction over 10 years, 

per m 

2 (ft2

), by building type. The carbon emissions estimation approach is defined in 

Section 5.3. 

Table 6-8 Average Per Unit Change in Carbon Emissions, 10-Year, Illinois 

Building Standard Edition 

Type LEC 

kg/m2 lb/ft2 

APART04 -174.0 -35.6 

APART06 -205.5 -42.1 

DORMI04 -143.3 -29.3 

DORMI06 -218.8 -44.8 

HOTEL15 -206.2 -42.2 

HIGHS02 -220.0 -45.1 

OFFIC03 -216.3 -44.3 

OFFIC08 -194.4 -39.8 

OFFIC16 -247.6 -50.7 

RETAIL1 -160.2 -32.8 

RSTRNT1 -420.0 -86.0 

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Illinois 

Table 6-9 applies the Table 6-8 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 adoption of 

the LEC design decreases carbon emissions for all building types and results in total 

savings of 795 350 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 

reductions in carbon emissions of 1.3 million metric tons over the 10-year study period. 

Table 6-9 Statewide Change in Total Carbon Emissions for One Year of 

Construction, 10-Year, Illinois – Metric Tons 

Building Subcategory m 2 ft2 Standard Edition
 

Type Weighting (1000s) (1000s)
 LEC 

APART04 44.9 % 656.5 7066 -114 232 

APART06 55.1 % 804.1 8655 -165 254 

HOTEL15 100.0 % 260.8 2807 -53 776 

HIGHS02 100.0 % 616.5 6636 -135 617 

OFFIC03 37.4 % 219.3 2361 -47 453 

OFFIC08 40.4 % 236.5 2546 -45 978 

OFFIC16 22.2 % 130.2 1401 -32 226 

RETAIL1 100.0 % 1132.1 12 186 -181 344 

RSTRNT1 100.0 % 46.4 499 -19 471 

Total 4102.5 44 159 -795 350 

Note: Dormitories are excluded because no such floor area category 

is reported in the construction data. 

6.2.4 Life-Cycle Costs 

Table 6-10 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. 

28
 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Illinois 

Table 6-10 Average Per Unit Change in Life-Cycle Costs, 10-Year, Illinois
 

Building Standard Edition 

Type LEC 

$/m2 $/ft2 

APART04 $3.56 $0.33 

APART06 $1.77 $0.16 

DORMI04 -$2.67 -$0.25 

DORMI06 -$1.74 -$0.16 

HOTEL15 $2.16 $0.20 

HIGHS02 -$10.70 -$0.99 

OFFIC03 -$22.08 -$2.05 

OFFIC08 -$20.37 -$1.89 

OFFIC16 $1.64 $0.15 

RETAIL1 -$3.26 -$0.30 

RSTRNT1 -$68.51 -$6.36 

Table 6-11 applies the Table 6-10 results to one year’s worth of new building 

construction in the state to estimate change 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 5 of 9 building types realizing reductions in life-cycle costs. 

Overall, the LEC design results in a decrease of $18.6 million in statewide life-cycle 

costs relative to ASHRAE 90.1-2007. High schools, 3-story office buildings, and 8-story 

office buildings realize the greatest statewide decrease in life-cycle costs ($6.6 million, 

$4.8 million, and $4.8 million, 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 $31.4 million over the 10-year study period. 

29
 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Illinois 

Table 6-11 Statewide Change in Life-Cycle Costs for One Year of Construction, 

10-Year, Illinois 

Building Subcategory m 2 ft2 Standard Edition
 

Type Weighting (1000s) (1000s) LEC
 

APART04 44.9 % 656.5 7066 $2 337 211
 

APART06 55.1 % 804.1 8655 $1 420 712
 

HOTEL15 100.0 % 260.8 2807 $563 277 

HIGHS02 100.0 % 616.5 6636 -$6 595 166 

OFFIC03 37.4 % 219.3 2361 -$4 844 198 

OFFIC08 40.4 % 236.5 2546 -$4 817 556 

OFFIC16 22.2 % 130.2 1401 $213 398 

RETAIL1 100.0 % 1132.1 12 186 -$3 691 062 

RSTRNT1 100.0 % 46.4 499 -$3 178 642 

Total 4102.5 44 159 -$18 592 026 

Note: Dormitories are excluded because no such floor area category 

is reported in the construction data. 

6.3 State Summary 

Illinois 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, 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 1212.7 GWh (4140.6 GBtu), energy cost savings of $124.4 million, 

and carbon emissions reductions of 1.3 million metric tons while decreasing life-cycle 

costs by $31.4 million for one year’s worth of commercial building construction. 

30
 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

7 

Indiana 

Indiana 

Indiana has adopted ASHRAE 90.1-2007 as its state energy code, is located in the East 

North Central Census Division, and spans two climate zones (Zone 4A and Zone 5A). 

Table 7-1 provides an overview of Indiana’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 84 kWh/m2 to 

103 kWh/m2 (27 kBtu/ft2 to 33 kBtu/ft2

) annually. The high school uses the greatest 

amount of energy at 221 kWh/m2 to 236 kWh/m2 (70 kBtu/ft2 to 75 kBtu/ft2) annually. 

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

Indiana 

Building 

Type 

Standard Edition 

2007 

kWh/m2 kBtu/ft2 

LEC 

kWh/m2 kBtu/ft2 

APART04 

APART06 

163 52 

162 51 

146 46 

143 45 

DORMI04 

DORMI06 

125 40 

178 56 

110 35 

158 50 

HOTEL15 168 53 147 47 

HIGHS02 236 75 221 70 

OFFIC03 

OFFIC08 

OFFIC16 

113 36 

103 33 

160 51 

92 29 

84 27 

136 43 

RETAIL1 122 39 106 34 

RSTRNT1 171 54 128 41 

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. 

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 the LEC design in the state of Indiana. 

7.1.1 Statewide Building Comparison 

Table 7-2 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 

31
 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Indiana 

ASHRAE 90.1-2007, ranging from -6.4 % to -24.8 % depending on the building type with 

an overall average of -13.9 %. High schools realize the lowest reductions in energy use 

while restaurants realize the greatest reductions in energy use. 

Table 7-2 Average Percentage Change from Adoption of Newer Standard Editions, 

10-Year, Indiana 

Building LEC 

Type Energy Use Energy Cost Carbon LCC 

APART04 -10.1 -16.0 -17.1 0.6 

APART06 -11.3 -18.7 -20.1 0.5 

DORMI04 -11.8 -16.9 -17.9 -0.4 

DORMI06 -11.0 -18.1 -19.4 0.2 

HOTEL15 -12.3 -18.1 -19.2 0.5 

HIGHS02 -6.4 -14.8 -16.6 -0.8 

OFFIC03 -18.3 -22.4 -23.0 -2.1 

OFFIC08 -18.5 -20.8 -21.1 -2.0 

OFFIC16 -15.0 -19.7 -20.4 0.6 

RETAIL1 -13.5 -16.8 -17.4 0.5 

RSTRNT1 -24.8 -31.9 -33.1 -4.3 

Average -13.9 -19.5 -20.5 -0.6 

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 -14.8 % to -31.9 % depending 

on the building type with an average of -19.5 % 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. 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 

40.6 % 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 change in energy-related carbon emissions 

across building types for the LEC design relative to ASHRAE 90.1-2007, ranging 

from -16.6 % to -33.1 % with an average of -20.5 %. 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 

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Indiana 

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 percentage change in life-cycle costs varies across building types, ranging 

from -4.3 % to 0.6 % 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 -0.6 % 

in life-cycle costs, the LEC design may be cost-effective if the state adopted it as its state 

energy code for commercial buildings. 

7.1.2 City Comparisons 

Simulations are run for five cities located in Indiana: Evansville in Zone 4A and Fort 

Wayne, Indianapolis, and South Bend in Zone 5A. The results may vary across cities 

within Indiana 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 7-3 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 -13.0 % 

to -15.5 % with an overall average of -13.9 %. The city in Zone 4A (Evansville) realizes 

slightly greater reductions in energy consumption than cities in Zone 5A. 

Table 7-3 Average Percentage Change from Adoption of Newer Standard Editions 

by City, 10-Year, Indiana 

Cities Zone LEC 

Energy Use Energy Cost Carbon LCC 

Evansville 4A -15.5 -20.4 -21.4 -0.7 

Fort Wayne 5A -13.0 -18.9 -20.2 -0.7 

Indianapolis 5A -14.1 -19.8 -21.0 -0.6 

South Bend 5A -13.0 -18.8 -20.1 -0.5 

Average -13.9 -19.5 -20.7 -0.6 

The average percentage change in energy costs for all building types also varies 

minimally across cities, ranging from -18.8 % to -20.4 % for 10 years of operation. The 

33
 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Indiana 

city in Zone 4A (Evansville) realizes slightly greater reductions in energy costs than the 

cities in Zone 5A. For all cities, percentage reductions in energy costs are greater than 

percentage reductions in energy use because the percentage reduction in electricity is 

greater than the reduction in natural gas. Repeating the pattern, the average percentage 

change in carbon emissions for all building types also varies minimally across cities, 

ranging from -20.1 % to -21.4 %. Reductions in life-cycle costs for all building types 

vary minimally across cities, with the percentage change in life-cycle costs ranging 

from -0.5 % to -0.7 %. 

7.2 Total Savings 

How much can Indiana 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 7-4 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 7-5 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.17 

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.
 

34
 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Indiana 

Table 7-4 Average Per Unit Change in Annual Energy Use, Indiana
 

Building Standard Edition 

Type LEC 

kWh/m2 kBtu/ft2 

APART04 -16.31 -5.17 

APART06 -18.14 -5.75 

DORMI04 -14.67 -4.65 

DORMI06 -19.49 -6.18 

HOTEL15 -20.52 -6.51 

HIGHS02 -20.62 -6.54 

OFFIC03 -14.82 -4.70 

OFFIC08 -18.97 -6.02 

OFFIC16 -23.92 -7.59 

RETAIL1 -16.45 -5.22 

RSTRNT1 -42.29 -13.41 

The adoption of the LEC design as the state’s energy code for commercial buildings 

would save energy for all building types and 32.6 GWh (111.2 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 49.6 % 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 65.7 GWh (224.3 GBtu) per year. These savings imply 656.9 GWh (2242.9 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 retail stores and high schools because they 

represent 36.4 % and 28.2 %, respectively, of the new construction in the state while all 

other building types represent 9.4 % or less. The amount of new construction overwhelms 

the relative percentage changes in energy use. The building types that lead to the greatest 

estimated reduction 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 7-2. 

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Indiana 

Table 7-5 Statewide Change in Annual Energy Use for One Year of Construction, 

Indiana 

Building Subcategory m 2 ft2 Standard Edition 

Type Weighting (1000s) (1000s) LEC 

kWh kBtu 

APART04 44.9 % 32.3 348 -527 760 -1 802 001
 

APART06 55.1 % 39.7 427 -718 938 -2 454 765
 

HOTEL15 100.0 % 171.1 1842 -3 512 056 -11 991 668 

HIGHS02 100.0 % 511.6 5507 -7 582 543 -25 890 062 

OFFIC03 37.4 % 130.7 1407 -2 694 285 -9 199 448 

OFFIC08 40.4 % 140.9 1517 -2 672 818 -9 126 150 

OFFIC16 22.2 % 77.6 835 -1 854 780 -6 333 016 

RETAIL1 100.0 % 660.4 7108 -10 859 260 -37 078 183 

RSTRNT1 100.0 % 51.0 549 -2 158 534 -7 370 162 

Total 1815.2 19 539 -32 580 974 -111 245 456 

Note: Dormitories are excluded because no such floor area category is reported 

in the construction data. 

7.2.2 Energy Costs 

Table 7-6 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 7-6 Average Per Unit Change in Energy Costs, 10-Year, Indiana 

Building Standard Edition 

Type LEC 

$/m2 $/ft2 

APART04 -$11.85 -$1.10 

APART06 -$13.89 -$1.29 

DORMI04 -$9.86 -$0.92 

DORMI06 -$14.79 -$1.37 

HOTEL15 -$13.96 -$1.30 

HIGHS02 -$14.69 -$1.37 

OFFIC03 -$14.47 -$1.34 

OFFIC08 -$13.23 -$1.23 

OFFIC16 -$17.23 -$1.60 

RETAIL1 -$11.17 -$1.04 

RSTRNT1 -$29.14 -$2.71 

Table 7-7 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 $24.7 million for 10 years of building operation. 

36
 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Indiana 

Assuming that the buildings considered in this study, which represent 49.6 % 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 $49.8 million over the 10-year study 

period. 

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

10-Year, Indiana 

Building Subcategory m 2 ft2 Standard Edition
 

Type Weighting (1000s) (1000s) LEC
 

APART04 44.9 % 32.3 348 -$383 546 

APART06 55.1 % 39.7 427 -$550 457 

HOTEL15 100.0 % 171.1 1842 -$2 388 096 

HIGHS02 100.0 % 511.6 5507 -$7 403 619 

OFFIC03 37.4 % 130.7 1407 -$1 920 306 

OFFIC08 40.4 % 140.9 1517 -$1 864 299 

OFFIC16 22.2 % 77.6 835 -$1 335 702 

RETAIL1 100.0 % 660.4 7108 -$7 375 366 

RSTRNT1 100.0 % 51.0 549 -$1 487 185 

Total 1815.2 19 539 -$24 708 576 

Note: Dormitories are excluded because no such floor area category 

is reported in the construction data. 

7.2.3 Energy-related Carbon Emissions 

Table 7-8 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 7-8 Average Per Unit Change in Carbon Emissions, 10-Year, Indiana 

Building Standard Edition 

Type LEC 

kg/m2 lb/ft2 

APART04 -154.6 -31.7 

APART06 -182.1 -37.3 

DORMI04 -127.4 -26.1 

DORMI06 -193.7 -39.7 

HOTEL15 -180.6 -37.0 

HIGHS02 -194.1 -39.8 

OFFIC03 -191.2 -39.2 

OFFIC08 -171.7 -35.2 

OFFIC16 -224.4 -46.0 

RETAIL1 -144.5 -29.6 

RSTRNT1 -377.7 -77.4 

37
 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Indiana 

Table 7-9 applies the Table 7-8 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 339 945 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 652 713 metric tons over the 10-year study 

period. 

Table 7-9 Statewide Change in Total Carbon Emissions for One Year of 

Construction, 10-Year, Indiana – Metric Tons 

Building Subcategory m 2 ft2 Standard Edition
 

Type Weighting (1000s) (1000s)
 LEC 

APART04 44.9 % 32.3 348 -5002 

APART06 55.1 % 39.7 427 -7220 

HOTEL15 100.0 % 171.1 1842 -47 109 

HIGHS02 100.0 % 511.6 5507 -99 293 

OFFIC03 37.4 % 130.7 1407 -24 991 

OFFIC08 40.4 % 140.9 1517 -24 202 

OFFIC16 22.2 % 77.6 835 -17 403 

RETAIL1 100.0 % 660.4 7108 -95 447 

RSTRNT1 100.0 % 51.0 549 -19 279 

Total 1815.2 19 539 -339 945 

Note: Dormitories are excluded because no such floor area category 

is reported in the construction data. 

7.2.4 Life-Cycle Costs 

Table 7-10 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. 

38
 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Indiana 

Table 7-10 Average Per Unit Change in Life-Cycle Costs, 10-Year, Indiana
 

Building Standard Edition 

Type LEC 

$/m2 $/ft2 

APART04 $5.82 $0.54 

APART06 $4.61 $0.43 

DORMI04 -$3.73 -$0.35 

DORMI06 $1.61 $0.15 

HOTEL15 $4.76 $0.44 

HIGHS02 -$6.50 -$0.60 

OFFIC03 -$16.63 -$1.54 

OFFIC08 -$16.84 -$1.56 

OFFIC16 $4.41 $0.41 

RETAIL1 $3.43 $0.32 

RSTRNT1 -$57.55 -$5.35 

Table 7-11 applies the Table 7-10 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 $6.6 million in statewide life-cycle costs 

relative to ASHRAE 90.1-2007. High schools and restaurants realize the greatest 

statewide decreases in life-cycle costs ($3.3 million and $2.9 million, respectively) while 

16-story office buildings realize the greatest increase in life-cycle costs ($341 733) 

followed by the 4- and 6-story apartment buildings ($188 320 and $182 538, 

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 

$13.3 million over the 10-year study period. 

39
 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Indiana 

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

10-Year, Indiana 

Building Subcategory m 2 ft2 Standard Edition
 

Type Weighting (1000s) (1000s) LEC
 

APART04 44.9 % 32.3 348 $188 320
 

APART06 55.1 % 39.7 427 $182 538
 

HOTEL15 100.0 % 171.1 1842 $1 242 497 

HIGHS02 100.0 % 511.6 5507 -$3 326 796 

OFFIC03 37.4 % 130.7 1407 -$2 173 058 

OFFIC08 40.4 % 140.9 1517 -$2 373 101 

OFFIC16 22.2 % 77.6 835 $341 733 

RETAIL1 100.0 % 660.4 7108 $2 265 648 

RSTRNT1 100.0 % 51.0 549 -$2 937 651 

Total 1815.2 19 539 -$6 589 870 

Note: Dormitories are excluded because no such floor area category 

is reported in the construction data. 

7.3 State Summary 

Indiana 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 656.9 GWh (2242.9 GBtu), energy cost 

savings of $49.8 million, and carbon emissions reductions of 652 713 metric tons while 

decreasing life-cycle costs by $13.3 million for one year’s worth of commercial building 

construction. 

40
 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

8 

Iowa 

Iowa 

Iowa has adopted ASHRAE 90.1-2007 as its state energy code, is located in the West 

North Central Census Division, and spans two climate zones (Zone 5A and Zone 6A). 

Table 8-1 provides an overview of Iowa’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 91 kWh/m2 to 110 kWh/m2 

(29 kBtu/ft2 to 35 kBtu/ft2) annually. The high school uses the greatest amount of energy 

at 258 kWh/m2 to 275 kWh/m2 (87 kBtu/ft2 to 82 kBtu/ft2) annually. 

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

Iowa 

Building 

Type 

Standard Edition 

2007 

kWh/m2 kBtu/ft2 

LEC 

kWh/m2 kBtu/ft2 

APART04 

APART06 

180 57 

179 57 

162 52 

160 51 

DORMI04 

DORMI06 

142 45 

199 63 

125 40 

179 57 

HOTEL15 190 60 169 54 

HIGHS02 275 87 258 82 

OFFIC03 

OFFIC08 

OFFIC16 

122 39 

110 35 

178 56 

100 32 

91 29 

155 49 

RETAIL1 138 44 118 37 

RSTRNT1 189 60 144 46 

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 

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 Iowa. 

8.1.1 Statewide Building Comparison 

Table 8-2 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 

41
 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Iowa 

ASHRAE 90.1-2007, ranging from -6.1 % to -23.7 % depending on the building type with 

an overall average of -13.2 %. 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, Iowa 

Building LEC 

Type Energy Use Energy Cost Carbon LCC 

APART04 -9.8 -15.8 -16.8 0.5 

APART06 -10.6 -17.6 -18.7 0.5 

DORMI04 -11.7 -16.7 -17.5 -0.2 

DORMI06 -10.0 -16.4 -17.4 0.2 

HOTEL15 -11.0 -15.3 -16.0 0.5 

HIGHS02 -6.1 -13.8 -15.2 -0.8 

OFFIC03 -17.7 -21.4 -21.9 -1.7 

OFFIC08 -17.3 -19.6 -19.8 -1.5 

OFFIC16 -13.0 -16.2 -16.6 0.6 

RETAIL1 -14.3 -17.2 -17.6 0.6 

RSTRNT1 -23.7 -30.3 -31.2 -4.4 

Average -13.2 -18.2 -19.0 -0.5 

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 -15.3 % to -30.3 % depending 

on the building type with an average of -18.2 % 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. For 4 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 

28.7 % 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 change in energy-related carbon emissions 

across building types for the LEC design relative to ASHRAE 90.1-2007, ranging 

from -15.2 % to -31.2 % with an average of -19.0 %. 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 

42
 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Iowa 

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 4 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 -4.4 % to 0.6 % for a 10-year study period. Five of the 11 building types realize 

reductions in life-cycle costs with restaurants realizing the greatest percentage reduction 

in life-cycle costs while retail stores and 16-story office buildings realizing the largest 

increase in life-cycle costs (0.6 %). Based on the overall average percentage change 

of -0.5 % 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 five cities located in Iowa: Burlington, Des Moines, and Sioux 

City in Zone 5A, and Mason City and Waterloo in Zone 6A. The results may vary across 

cities within Iowa 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. 

Table 8-3 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 varies minimally across cities, ranging from -12.7 % 

to -13.9 % with an overall average of -13.2 %. The cities in Zone 5A realize slightly 

greater changes, on average, than cities in Zone 6A (-13.4 % versus -12.9 %). 

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

by City, 10-Year, Iowa 

Cities Zone LEC 

Burlington 

Des Moines 

Sioux City 

Mason City 

Waterloo 

Average 

5A 

5A 

5A 

6A 

6A 

Energy Use 

-13.9 

-13.4 

-13.0 

-12.7 

-13.1 

-13.2 

Energy Cost 

-19.6 

-19.4 

-19.1 

-16.3 

-16.6 

-18.2 

Carbon 

-20.7 

-20.5 

-20.2 

-17.1 

-17.4 

-19.2 

LCC 

-0.6 

-0.5 

-0.4 

-0.5 

-0.4 

-0.5 

43 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Iowa 

The average percentage change in energy costs for all building types varies across cities, 

ranging from -16.3 % to -19.6 % for 10 years of operation. Cities in the warmer climate 

zone (Zone 5A) realize a greater reduction in energy costs than cities in the colder 

climate zone (Zone 6A). 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 -17.1 % to -20.7 % with cities in the warmer climate zone realizing greater 

reductions in carbon emissions. Changes in life-cycle costs for all building types vary 

minimally across cities, with the percentage change in life-cycle costs ranging 

from -0.4 % to -0.6 %. There are no distinct trends across cities within different climate 

zones. 

8.2 Total Savings 

How much can Iowa 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. 

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.18 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.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.
 

44
 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Iowa 

Table 8-4 Average Per Unit Change in Annual Energy Use, Iowa
 

Building Standard Edition 

Type LEC 

kWh/m2 kBtu/ft2 

APART04 -17.7 -5.6 

APART06 -18.9 -6.0 

DORMI04 -16.6 -5.3 

DORMI06 -19.7 -6.3 

HOTEL15 -20.7 -6.6 

HIGHS02 -21.6 -6.9 

OFFIC03 -16.8 -5.3 

OFFIC08 -19.0 -6.0 

OFFIC16 -23.0 -7.3 

RETAIL1 -19.7 -6.3 

RSTRNT1 -44.7 -14.2 

The adoption of the LEC design as the state’s energy code for commercial buildings 

would save energy for all building types and 16.7 GWh (57.0 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 58.8 % 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 statewide savings to 

be 28.4 GWh (96.9 GBtu) per year. These savings imply 283.7 GWh (968.6 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 31.7 % and 29.7 %, 

respectively, of the new construction in the state while all other building types represent 

10.0 % 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 11th in percentage reduction, respectively, among the 11 building types, as 

reported in Table 8-2. 

45
 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Iowa 

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

Iowa 

Building Subcategory m 2 ft2 Standard Edition 

Type Weighting (1000s) (1000s) LEC 

kWh kBtu 

APART04 44.9 % 12.9 139 -228 180 -779 104 

APART06 55.1 % 15.8 170 -298 046 -1 017 658 

HOTEL15 100.0 % 85.4 920 -1 766 677 -6 032 195 

HIGHS02 100.0 % 252.4 2,717 -4 236 977 -14 466 863 

OFFIC03 37.4 % 74.8 805 -1 617 890 -5 524 174 

OFFIC08 40.4 % 80.6 868 -1 530 617 -5 226 186 

OFFIC16 22.2 % 44.4 477 -1 019 674 -3 481 606 

RETAIL1 100.0 % 270.1 2,907 -5 320 922 -18 167 916 

RSTRNT1 100.0 % 14.8 159 -661 793 -2 259 645 

Total 851.1 9,161 -16 680 777 -56 955 346 

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. 

Table 8-6 Average Per Unit Change in Energy Costs, 10-Year, Iowa 

Building Standard Edition 

Type LEC 

$/m2 $/ft2 

APART04 -$10.94 -$1.02 

APART06 -$12.18 -$1.13 

DORMI04 -$9.16 -$0.85 

DORMI06 -$12.59 -$1.17 

HOTEL15 -$11.29 -$1.05 

HIGHS02 -$12.97 -$1.20 

OFFIC03 -$13.07 -$1.21 

OFFIC08 -$11.47 -$1.07 

OFFIC16 -$13.39 -$1.24 

RETAIL1 -$10.74 -$1.00 

RSTRNT1 -$25.70 -$2.39 

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 

statewide reductions in energy costs of $10.4 million for 10 years of building operation. 

46
 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Iowa 

Assuming that the buildings considered in this study, which represent 58.8 % 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 the LEC design can be extrapolated 

to estimate the total statewide energy cost savings of $17.6 million over the 10-year study 

period. 

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

10-Year, Iowa 

Building Subcategory m 2 ft2 Standard Edition
 

Type Weighting (1000s) (1000s) LEC
 

APART04 44.9 % 12.9 139 -$140 931 

APART06 55.1 % 15.8 170 -$192 129 

HOTEL15 100.0 % 85.4 920 -$964 872 

HIGHS02 100.0 % 252.4 2717 -$3 300 522 

OFFIC03 37.4 % 74.8 805 -$969 233
 

OFFIC08 40.4 % 80.6 868 -$924 268
 

OFFIC16 22.2 % 44.4 477 -$593 818 

RETAIL1 100.0 % 270.1 2907 -$2 899 061 

RSTRNT1 100.0 % 14.8 159 -$380 105 

Total 851.1 9161 -$10 364 938 

Note: Dormitories are excluded because no such floor area category 

is reported in the construction data. 

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, Iowa 

Building Standard Edition 

Type LEC 

kg/m2 lb/ft2 

APART04 -159.1 -32.6 

APART06 -177.8 -36.4 

DORMI04 -131.7 -27.0 

DORMI06 -183.6 -37.6 

HOTEL15 -162.2 -33.2 

HIGHS02 -193.8 -39.7 

OFFIC03 -188.0 -38.5 

OFFIC08 -166.3 -34.1 

OFFIC16 -193.5 -39.6 

RETAIL1 -154.1 -31.6 

RSTRNT1 -371.0 -76.0 

47
 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Iowa 

Table 8-9 applies the Table 8-8 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 reductions 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 150 791 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 256 448 metric tons over the 10-year study 

period. 

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

Construction, 10-Year, Iowa – Metric Tons 

Building Subcategory m 2 ft2 Standard Edition
 

Type Weighting (1000s) (1000s)
 LEC 

APART04 44.9 % 12.9 139 -2049 

APART06 55.1 % 15.8 170 -2805 

HOTEL15 100.0 % 85.4 920 -13 855 

HIGHS02 100.0 % 252.4 2717 -48 934 

OFFIC03 37.4 % 74.8 805 -14 051
 

OFFIC08 40.4 % 80.6 868 -13 410
 

OFFIC16 22.2 % 44.4 477 -8584 

RETAIL1 100.0 % 270.1 2907 -41 617 

RSTRNT1 100.0 % 14.8 159 -5487 

Total 851.1 9,161 -150 791 

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. 

48
 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Iowa 

Table 8-10 Average Per Unit Change in Life-Cycle Costs, 10-Year, Iowa
 

Building Standard Edition 

Type LEC 

$/m2 $/ft2 

APART04 $5.17 $0.48 

APART06 $4.68 $0.43 

DORMI04 -$1.99 -$0.18 

DORMI06 $2.07 $0.19 

HOTEL15 $4.39 $0.41 

HIGHS02 -$5.85 -$0.54 

OFFIC03 -$12.47 -$1.16 

OFFIC08 -$11.37 -$1.06 

OFFIC16 $4.41 $0.41 

RETAIL1 $3.97 $0.37 

RSTRNT1 -$54.48 -$5.06 

Table 8-11 applies the Table 8-10 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 $2.3 million in statewide life-cycle costs 

relative to ASHRAE 90.1-2007. High schools, 3-story office buildings, and 8-story office 

buildings realize the greatest statewide decrease in life-cycle costs ($1.5 million, 

$932 258, and $916 947, respectively) while retail stores realize the largest increase in 

life-cycle costs of $1.1 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 $4.0 million over the 10-year study period. 

49
 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Iowa 

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

10-Year, Iowa 

Building Subcategory m 2 ft2 Standard Edition
 

Type Weighting (1000s) (1000s) LEC
 

APART04 44.9 % 12.9 139 $66 586 

APART06 55.1 % 15.8 170 $73 778 

HOTEL15 100.0 % 85.4 920 $374 685 

HIGHS02 100.0 % 252.4 2717 -$1 476 955 

OFFIC03 37.4 % 74.8 805 -$932 258 

OFFIC08 40.4 % 80.6 868 -$916 947 

OFFIC16 22.2 % 44.4 477 $195 513 

RETAIL1 100.0 % 270.1 2907 $1 073 263 

RSTRNT1 100.0 % 14.8 159 -$805 723 

Total 851.1 9161 -$2 348 057 

Note: Dormitories are excluded because no such floor area category 

is reported in the construction data. 

8.3 State Summary 

Iowa 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 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 283.7 GWh (968.6 GBtu), energy cost savings of $17.6 million, 

and carbon emissions reductions of 256 448 metric tons while decreasing life-cycle costs 

by $4.0 million for one year’s worth of commercial building construction. 

50
 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

9 

Kansas 

Kansas 

Kansas is located in the West North Central Census Division and spans the warmest 

climate zones in the Midwest Census Region (Zone 4A and Zone 5A). 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 9-1 provides 

an overview of Kansas’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 84 kWh/m2 to 124 kWh/m2 

(27 kBtu/ft2 to 39 kBtu/ft2) annually. The high school uses the greatest amount of energy 

at 205 kWh/m2 to 238 kWh/m2 (65 kBtu/ft2 to 75 kBtu/ft2) annually. 

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

Kansas 

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 

183 58 

181 57 

181 58 

179 57 

160 51 

158 50 

154 49 

153 48 

137 44 

134 42 

DORMI04 

DORMI06 

143 45 

197 62 

140 44 

194 62 

124 39 

171 54 

118 38 

169 53 

103 33 

148 47 

HOTEL15 171 54 169 54 151 48 159 50 137 44 

HIGHS02 238 75 236 75 229 73 221 70 205 65 

OFFIC03 

OFFIC08 

OFFIC16 

132 42 

124 39 

158 50 

129 41 

121 38 

157 50 

121 38 

111 35 

148 47 

112 36 

104 33 

157 50 

90 29 

84 27 

131 42 

RETAIL1 152 48 150 48 137 44 123 39 106 33 

RSTRNT1 213 67 208 66 190 60 174 55 126 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. 

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 Kansas. 

51
 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Kansas 

9.1.1 Energy Use 

Table 9-2 shows 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 2.5 % or less. There is a small 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 -13.1 % with an average of -10.3 %. The average change in energy use from 

constructing buildings using ASHRAE 90.1-2007 requirements ranges from -1.0 % 

to -19.4 %, with an overall average of -13.3 %. The smallest reductions in energy use are 

realized by the buildings with the greatest window-to-wall ratios: the 16-story office 

building, 15-story hotel, and high school. 

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

Standard Editions, Kansas 

Building Standard Edition 

Type 2001 2004 2007 LEC 

APART04 -0.7 -12.5 -15.7 -24.9 

APART06 -0.7 -12.7 -15.4 -25.9 

DORMI04 -2.1 -13.1 -17.2 -27.6 

DORMI06 -1.2 -13.0 -14.3 -24.8 

HOTEL15 -1.0 -11.7 -7.0 -19.7 

HIGHS02 -0.6 -3.5 -7.1 -13.7 

OFFIC03 -2.1 -8.7 -15.0 -31.9 

OFFIC08 -2.5 -10.5 -16.0 -32.5 

OFFIC16 -1.1 -6.5 -1.0 -17.1 

RETAIL1 -1.5 -9.8 -19.4 -30.6 

RSTRNT1 -2.5 -10.8 -18.5 -40.8 

Average -1.5 -10.3 -13.3 -26.3 

For the high-rise buildings (15-story hotel and 16-story office building), ASHRAE 

90.1-2004 is actually more energy efficient than ASHRAE 90.1-2007 because the 

maximum window SHGC in Zone 4 and Zone 5 is increased from ASHRAE 90.1-2004 to 

ASHRAE 90.1-2007, making the requirement less strict. Additionally, the maximum 

U-factor is relaxed for Zone 4. The 100 % glazing amplifies the impact of these 

requirement relaxations 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 -13.7 % to -40.8 % with an average 

of -26.3 %. 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 less strict window SHGC requirement. 

52
 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Kansas 

9.1.2 Energy Costs 

Table 9-3 shows a minimal percentage change in energy costs over 10 years from 

adopting ASHRAE 90.1-2001 (-0.9 % to -3.0 %), 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 -7.5 % to -22.1 % depending on the 

building type with an average of -15.8 %. The average change in energy costs from 

constructing buildings using ASHRAE 90.1-2007 requirements ranges from -2.2 % 

to -24.4 %, with an overall average of -17.1 %. The LEC design realizes the greatest 

change in energy costs, with the average change by building type ranging from -21.6 % 

to -46.4 % with an average of -33.5 % overall. 

Table 9-3 Average Percentage Change in Energy Costs, 10-Year, Kansas 

Building Standard Edition 

Type 2001 2004 2007 LEC 

APART04 -0.9 -20.8 -23.0 -35.3 

APART06 -0.9 -20.9 -22.7 -37.4 

DORMI04 -2.6 -22.1 -24.4 -37.1 

DORMI06 -1.5 -21.1 -21.9 -36.3 

HOTEL15 -1.2 -19.3 -13.6 -29.4 

HIGHS02 -0.9 -7.5 -10.3 -23.4 

OFFIC03 -2.4 -11.2 -14.4 -34.3 

OFFIC08 -2.7 -12.5 -14.9 -33.1 

OFFIC16 -1.2 -8.8 -2.2 -21.6 

RETAIL1 -1.7 -14.4 -20.2 -33.9 

RSTRNT1 -3.0 -15.7 -20.1 -46.4 

Average -1.7 -15.8 -17.1 -33.5 

For all building designs, the average 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. 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. 

9.1.3 Energy-related Carbon Emissions 

Minimal change in energy use leads to small percentage reductions (3.1 % or less) in 

cradle-to-grave energy-related carbon emissions for the ASHRAE 90.1-2001 design 

across all building types. Table 9-4 shows a significant change in average energy-related 

53
 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Kansas 

carbon emissions for ASHRAE 90.1-2004 for all building types, ranging from -9.3 % 

to -25.2 % with an average of -17.8 %. 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 -2.7 % to -26.9 % with an overall average of -18.4 %. The LEC 

design leads to the greatest average changes in carbon emissions, ranging from -27.7 % 

to -48.3 % depending on the building type with an average of -36.1 % across all building 

types. 

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

Year, Kansas 

Building Standard Edition 

Type 2001 2004 2007 LEC 

APART04 -1.0 -23.8 -25.6 -39.1 

APART06 -1.0 -23.8 -25.3 -41.4 

DORMI04 -2.7 -25.2 -26.9 -40.4 

DORMI06 -1.6 -24.0 -24.7 -40.4 

HOTEL15 -1.3 -22.1 -15.9 -32.9 

HIGHS02 -1.1 -9.3 -11.6 -27.7 

OFFIC03 -2.5 -12.0 -14.3 -35.1 

OFFIC08 -2.8 -13.0 -14.6 -33.3 

OFFIC16 -1.3 -9.6 -2.7 -23.1 

RETAIL1 -1.8 -16.0 -20.5 -35.1 

RSTRNT1 -3.1 -17.3 -20.6 -48.3 

Average -1.8 -17.8 -18.4 -36.1 

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 further decreases carbon 

emissions because electricity has a higher carbon emissions rate per unit of energy than 

natural gas in Kansas. 

9.1.4 Life-Cycle Costs 

The most cost-effective building design for each building type is bolded in Table 9-5. 

Life-cycle costs increase for the ASHRAE 90.1-2001 design compared to ASHRAE 

90.1-1999 for 10 of 11 building types over a 10-year study period. Across all building 

designs, the current state energy code is the lowest cost option for four building types (4­

story dormitory, 3-story office building, 8-story office building, and retail store). 

ASHRAE 90.1-2004 and ASHRAE 90.1-2007 are the lowest cost building designs for two 

and three building types, respectively. The change in life-cycle costs for ASHRAE 

90.1-2004 and -2007 range from -2.7 % to 6.2 % depending on building type. The LEC 

design is the lowest cost building design for two building types and realizes a reduction 

54
 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Kansas 

in life-cycle costs for 6 of 11 building types, with the percentage change in life-cycle 

costs ranging from -2.6 % to 1.0 %. Based on the overall average percentage reduction in 

life-cycle costs of 0.7 %, the LEC design may be cost-effective if the state adopted it as 

its state energy code for commercial buildings, while the other three designs may not be 

cost effective. 

Table 9-5 Average Percentage Change in Life-Cycle Costs, 10-Year, Kansas 

Building Standard Edition 

Type 2001 2004 2007 LEC 

APART04 0.0 -1.9 -2.2 -1.6 

APART06 0.0 -2.0 -2.3 -1.8 

DORMI04 4.5 0.9 0.3 0.3 

DORMI06 -0.1 -2.6 -2.7 -2.6 

HOTEL15 0.0 -2.5 -2.0 -1.5 

HIGHS02 0.5 -0.4 -0.8 -1.5 

OFFIC03 6.3 3.9 3.3 0.7 

OFFIC08 6.4 4.0 3.0 0.3 

OFFIC16 0.0 -1.0 -0.2 0.3 

RETAIL1 3.7 1.2 0.2 1.0 

RSTRNT1 8.3 6.2 4.9 -1.2 

Average 2.7 0.5 0.1 -0.7 

9.1.5 City Comparisons 

Simulations are run for four cities located in Kansas: Dodge City, Topeka, and Wichita in 

Climate Zone 4A and Goodland in Climate Zone 5A. The results may vary across cities 

within Kansas for three 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 9-6, average reductions in energy use for all building types from 

adopting newer energy standard editions varies minimally across climate zones. The 

adoption of ASHRAE 90.1-2001, -2004, -2007, or the LEC design leads to slightly greater 

reductions for Zone 4A than for Zone 5A. There is also minimal variation within a 

climate zone. 

55
 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Kansas 

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

Standard Editions by City, Kansas 

Cities Zone Standard Edition 

2001 2004 2007 LEC 

Dodge City 4A -1.5 -10.3 -13.5 -26.8 

Topeka 4A -1.6 -10.3 -13.3 -26.1 

Wichita 4A -1.6 -10.8 -13.8 -27.2 

Goodland 5A -1.2 -9.6 -12.7 -25.2 

Average -1.5 -10.3 -13.3 -26.3 

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 9-7 shows that the climate zone 

with the greatest reduction in energy use realizes the greatest reduction in energy costs 

for each of the building designs. Both climate zones realize larger percentage reductions 

in energy costs than percentage reductions in energy use 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, the 

greater reduction in electricity leads to an additional reduction in energy costs. 

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

Cities Zone Standard Edition 

2001 2004 2007 LEC 

Dodge City 4A -1.8 -15.8 -17.1 -33.7 

Topeka 4A -1.9 -15.8 -16.9 -33.1 

Wichita 4A -1.8 -16.0 -17.1 -33.8 

Goodland 5A -1.5 -15.8 -17.1 -33.3 

Average -1.7 -15.8 -17.1 -33.5 

Table 9-8 reports changes in energy-related carbon emissions by city for Kansas. For all 

cities, the more stringent standard editions result in greater reductions in carbon 

emissions. The cities that realize the greatest reductions in energy use do not necessarily 

realize the greatest reductions in carbon emissions due to the variation in the fuel source 

of the energy use reductions. 

56
 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Kansas 

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

Kansas 

Cities Zone Standard Edition 

2001 2004 2007 LEC 

Dodge City 4A -1.7 -17.0 -18.0 -36.2 

Topeka 4A -1.8 -17.0 -17.9 -35.6 

Wichita 4A -1.7 -17.0 -18.0 -36.0 

Goodland 5A -1.4 -17.2 -18.3 -36.2 

Average -1.7 -17.1 -18.1 -36.0 

The data reported in Table 9-9 show that, over a 10-year period, average life-cycle costs 

increase for all cities for the ASHRAE 90.1-2001 and -2004 designs compared to 

ASHRAE 90.1-1999. Adoption of the ASHRAE 90.1-2007 design results in average 

reductions in life-cycle costs for two of the four cities relative to ASHRAE 90.1-1999. 

Adoption of the LEC design realizes the greatest average percentage reductions in 

life-cycle costs for all cities in both climate zones. For the LEC design, buildings in 

Wichita and Goodland realize greater reductions in life-cycle costs than buildings in 

Dodge City and Topeka. 

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

Cities Zone Standard Edition 

2001 2004 2007 LEC 

Dodge City 4A 3.2 0.8 0.4 -0.4 

Topeka 4A 3.0 1.0 0.5 -0.4 

Wichita 4A 2.5 0.3 -0.1 -1.0 

Goodland 5A 2.1 0.0 -0.3 -1.0 

Average 2.7 0.5 0.1 -0.7 

9.2 Total Savings 

How much can Kansas 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. 

57
 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Kansas 

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.20 The reduction per m2 (ft2

) is multiplied by the estimated 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 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.21 

Table 9-10 Average Per Unit Change in Annual Energy Use, Kansas 

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 

-1.31 -0.41 

-1.34 -0.43 

-22.82 -7.24 

-22.97 -7.29 

-28.65 -9.09 

-27.81 -8.82 

-45.43 -14.41 

-46.83 -14.86 

DORMI04 

DORMI06 

-3.02 -0.96 

-2.44 -0.77 

-18.75 -5.95 

-25.67 -8.14 

-24.57 -7.80 

-28.27 -8.97 

-39.54 -12.54 

-48.93 -15.52 

HOTEL15 -1.68 -0.53 -19.96 -6.33 -11.99 -3.80 -33.66 -10.68 

HIGHS02 -1.53 -0.49 -11.45 -3.63 -19.83 -6.29 -42.22 -13.39 

OFFIC03 

OFFIC08 

OFFIC16 

-2.80 -0.89 

-3.13 -0.99 

-1.67 -0.53 

-8.39 -2.66 

-13.05 -4.14 

-10.28 -3.26 

-16.97 -5.38 

-19.88 -6.31 

-1.54 -0.49 

-32.43 -10.29 

-40.29 -12.78 

-27.05 -8.58 

RETAIL1 -2.22 -0.70 -14.96 -4.74 -29.56 -9.38 -46.63 -14.79 

RSTRNT1 -5.29 -1.68 -23.07 -7.32 -39.27 -12.46 -86.72 -27.51 

The annual reduction in energy use shown in Table 9-11 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 1.5 GWh (5.0 GBtu), 9.1 GWh 

(31.1 GBtu), and 14.4 GWh (49.0 GBtu), respectively. The adoption of the LEC design 

as the state’s energy code would save energy for all building types and 27.5 GWh 

(93.7 GBtu) of total energy use annually for one year’s worth of new construction for 

these building types. 

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.
 

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Kansas 

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

Kansas 

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 % 

8.8 

10.8 

95 

116 

-12 -39 

-15 -49 

-201 -688 

-248 -848 

-253 -864 

-301 -1027 

-401 -1369 

-506 -1729 

HOTEL15 100.0 % 70.5 759 -118 -404 -1407 -4804 -845 -2886 -2374 -8104 

HIGHS02 100.0 % 165.2 1778 -253 -864 -1385 -4730 -2804 -9575 -5358 -18 295 

OFFIC03 

OFFIC08 

OFFIC16 

37.4 % 

40.4 % 

22.2 % 

65.7 

70.8 

39.0 

707 

762 

419 

-184 -627 

-222 -757 

-65 -222 

-752 -2568 

-924 -3155 

-400 -1367 

-1302 -4445 

-1408 -4807 

-60 -205 

-2773 -9467 

-2853 -9741 

-1054 -3599 

RETAIL1 100.0 % 224.4 2415 -498 -1700 -3356 -11 459 -6633 -22 648 -10 462 -35 722 

RSTRNT1 100.0 % 19.3 208 -102 -349 -445 -1521 -758 -2588 -1674 -5716 

Total 674.5 7260 -1468 -5012 -9120 -31 140 -14 364 -49 046 -27 454 -93 741 

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 62.6 % 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 the total 

statewide savings from adopting the LEC design in new commercial buildings to be 43.9 

GWh (149.8 GBtu) per year. These savings imply 438.6 GWh (1497.5 GBtu) in energy 

use savings over the 10-year study period. In comparison, ASHRAE 90.1-2007 would 

save 22.9 GWh (78.3 GBtu) annually or 229.5 GWh (783.5 GBtu) over the 10-year study 

period. 

The variation in The statewide change in energy use across the 9 building types with 

reported floor area data is consistent across the ASHRAE 90.1-2001, 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. The greatest total reductions are 

realized by retail stores and high schools because they represent 33.2 % and 24.5 %, 

respectively, of the new construction in the state while all other building types represent 

10.5 % 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 -- rank 4th and 11th in 

percentage reduction, respectively, among the 11 building types, as reported in Table 9-2. 

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, state average 

energy cost rates, and regional energy price escalation rates as defined in Section 3.2. 

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Kansas 

Table 9-12 Average Per Unit Change in Energy Costs, 10-Year, Kansas
 

Building Standard Edition 

Type 2001 

$/m2 $/ft2 

2004 

$/m2 $/ft2 

2007 

$/m2 $/ft2 

LEC 

$/m2 $/ft2 

APART04 

APART06 

-$0.84 

-$0.86 

-$0.08 

-$0.08 

-$19.30 

-$19.37 

-$1.79 

-$1.80 

-$21.35 

-$21.05 

-$1.98 

-$1.96 

-$32.83 

-$34.69 

-$3.05 

-$3.22 

DORMI04 

DORMI06 

-$1.93 

-$1.56 

-$0.18 

-$0.15 

-$16.55 

-$21.46 

-$1.54 

-$1.99 

-$18.29 

-$22.33 

-$1.70 

-$2.07 

-$27.81 

-$36.95 

-$2.58 

-$3.43 

HOTEL15 -$1.07 -$0.10 -$16.84 -$1.56 -$11.82 -$1.10 -$25.62 -$2.38 

HIGHS02 -$1.79 -$0.17 -$8.39 -$0.78 -$10.80 -$1.00 -$25.67 -$2.39 

OFFIC03 

OFFIC08 

OFFIC16 

-$0.98 

-$2.00 

-$1.07 

-$0.09 

-$0.19 

-$0.10 

-$7.92 

-$9.13 

-$7.77 

-$0.74 

-$0.85 

-$0.72 

-$10.80 

-$10.92 

-$1.97 

-$1.00 

-$1.01 

-$0.18 

-$24.63 

-$24.27 

-$19.03 

-$2.29 

-$2.25 

-$1.77 

RETAIL1 -$1.42 -$0.13 -$11.72 -$1.09 -$16.42 -$1.53 -$27.58 -$2.56 

RSTRNT1 -$3.39 -$0.31 -$17.93 -$1.67 -$22.92 -$2.13 -$52.95 -$4.92 

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. All building types realize reductions in energy costs for 

all building designs. The ASHRAE 90.1-2001 design realizes small reductions in energy 

costs ($939 628). ASHRAE 90.1-2004, ASHRAE 90.1-2007, and the LEC design realize 

decreases in energy costs of $7.4 million, $8.7 million, and $17.9 million respectively. 

Assuming that the buildings considered in this study, which represent 62.6 % 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 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 $1.5 million, $11.7 million, $13.9 million, and 

$28.6 million over the 10-year study period, respectively. 

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Kansas 

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

10-Year, Kansas 

Building Subcategory m 2 ft2 Standard Edition 

Type Weighting (1000s) (1000s) 2001 2004 2007 LEC 

APART04 44.9 % 8.8 95 -$7391 -$170 327 -$188 472 -$289 790 

APART06 55.1 % 10.8 116 -$9274 -$209 447 -$227 611 -$375 075 

HOTEL15 100 % 70.5 759 -$75 735 -$1 187 351 -$833 740 -$1 806 462 

HIGHS02 100 % 165.2 1778 -$161 934 -$1 309 336 -$1 783 969 -$4 068 696 

OFFIC03 37.4 % 65.7 707 -$117 629 -$550 673 -$708 946 -$1 685 793 

OFFIC08 40.4 % 70.8 762 -$141 917 -$646 728 -$773 558 -$1 718 268 

OFFIC16 22.2 % 39.0 419 -$41 605 -$302 631 -$76 836 -$741 333 

RETAIL1 100 % 224.4 2415 -$318 772 -$2 628 930 -$3 684 580 -$6 188 319 

RSTRNT1 100 % 19.3 208 -$65 372 -$346 100 -$442 439 -$1 022 302 

Total 674.5 7260 -$939 628 -$7 351 522 -$8 720 153 -$17 896 038 

Note: Dormitories are excluded because no such floor area category is reported in the construction data. 

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, Kansas 

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 

-12.7 -2.6 

-13.0 -2.7 

-312.0 -63.9 

-313.0 -64.1 

-336.4 -68.9 

-332.8 -68.2 

-513.6 -105.2 

-545.8 -111.8 

DORMI04 

DORMI06 

-29.3 -6.0 

-23.7 -4.9 

-269.8 -55.3 

-346.2 -70.9 

-288.1 -59.0 

-356.2 -72.9 

-432.3 -88.6 

-583.8 -119.6 

HOTEL15 -16.3 -3.3 -272.1 -55.7 -196.4 -40.2 -405.5 -83.0 

HIGHS02 -14.9 -3.0 -130.7 -26.8 -163.7 -33.5 -389.6 -79.8 

OFFIC03 

OFFIC08 

OFFIC16 

-27.2 -5.6 

-30.4 -6.2 

-16.2 -3.3 

-131.6 -27.0 

-141.8 -29.0 

-122.8 -25.1 

-156.2 -32.0 

-158.5 -32.5 

-33.9 -7.0 

-384.3 -78.7 

-362.2 -74.2 

-295.8 -60.6 

RETAIL1 -21.6 -4.4 -186.6 -38.2 -239.1 -49.0 -409.5 -83.9 

RSTRNT1 -51.4 -10.5 -285.0 -58.4 -338.9 -69.4 -793.6 -162.5 

Table 9-15 applies the Table 9-14 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 all decrease carbon emissions for all building 

types. The adoption of ASHRAE 90.1-2004 and ASHRAE 90.1-2007 result in savings of 

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Kansas 

117 733 metric tons and 130 442 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 

272 962 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 designs 

can be extrapolated to estimate statewide reductions in carbon emissions of 188 136 

metric tons, 208 374 metric tons, and 436 042 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, Kansas – Metric Tons 

Building Subcategory m 2 ft2 Standard Edition 

Type Weighting (1000s) (1000s) 2001 2004 2007 LEC 

APART04 44.9 % 8.8 95 -112 -2753 -2969 -4533 

APART06 55.1 % 10.8 116 -140 -3373 -3586 -5882 

HOTEL15 100.0 % 70.5 759 -1150 -19 190 -13 846 -28 591 

HIGHS02 100.0 % 165.2 1778 -2458 -21 588 -27 032 -64 349 

OFFIC03 37.4 % 65.7 707 -1786 -8 644 -10 261 -25 239 

OFFIC08 40.4 % 70.8 762 -2154 -10 040 -11 223 -25 641 

OFFIC16 22.2 % 39.0 419 -631 -4778 -1321 -11 515 

RETAIL1 100.0 % 224.4 2415 -4839 -41 859 -53 655 -91 878 

RSTRNT1 100.0 % 19.3 208 -993 -5507 -6549 -15 335 

Total 674.5 7260 -14 264 -117 733 -130 442 -272 962 

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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Kansas 

Table 9-16 Average Per Unit Change in Life-Cycle Costs, 10-Year, Kansas
 

Building Standard Edition 

Type 2001 

$/m2 $/ft2 

2004 

$/m2 $/ft2 

2007 

$/m2 $/ft2 

LEC 

$/m2 $/ft2 

APART04 $0.43 $0.04 -$18.20 -$1.69 -$21.07 -$1.96 -$14.89 -$1.38 

APART06 -$0.10 -$0.01 -$18.88 -$1.75 -$21.17 -$1.97 -$16.63 -$1.55 

DORMI04 $39.69 $3.69 $8.09 $0.75 $3.09 $0.29 $2.65 $0.25 

DORMI06 -$1.02 -$0.10 -$25.11 -$2.33 -$26.16 -$2.43 -$24.84 -$2.31 

HOTEL15 -$0.35 -$0.03 -$23.04 -$2.14 -$17.76 -$1.65 -$13.58 -$1.26 

HIGHS02 $3.75 $0.35 -$3.14 -$0.29 -$6.43 -$0.60 -$11.78 -$1.09 

OFFIC03 $45.97 $4.27 $28.70 $2.67 $23.93 $2.22 $5.48 $0.51 

OFFIC08 $48.47 $4.50 $29.86 $2.77 $22.53 $2.09 $2.76 $0.26 

OFFIC16 $0.14 $0.01 -$6.76 -$0.63 -$1.47 -$0.14 $2.15 $0.20 

RETAIL1 $22.24 $2.07 $7.25 $0.67 $1.40 $0.13 $6.33 $0.59 

RSTRNT1 $99.66 $9.26 $75.14 $6.98 $59.04 $5.49 -$14.50 -$1.35 

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 state energy codes for commercial buildings. Total changes in lifecycle costs over the 10-year study period vary across building designs. Adoption of the 

ASHRAE 90.1-2001 design results in an increase in life-cycle costs for 7 of 9 building 

types and increases total life-cycle costs by $14.0 million. The ASHRAE 90.1-2004 and ­

2007 designs result in a decrease in life-cycle costs for 5 of 9 building types, but increase 

total life-cycle costs by $4.3 million and $1.8 million, respectively. The LEC design 

decreases life-cycle costs for 5 of 9 building types, and decreases total life-cycle costs by 

$1.4 million. For a 10-year study period, it is not cost-effective to adopt newer editions of 

ASHRAE 90.1, but it is cost-effective to adopt the LEC design as Kansas’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 lifecycle costs of $22.3 million, $6.9 million, $2.9 million, and -$2.3 million over the 10­

year study period, respectively. 

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Kansas 

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

10-Year, Kansas 

Building Subcategory m 2 ft2 Standard Edition 

Type Weighting (1000s) (1000s) 2001 2004 2007 LEC 

APART04 44.9 % 8.8 95 $3813 -$160 625 -$185 973 -$131 421 

APART06 55.1 % 10.8 116 -$1093 -$204 094 -$228 849 -$179 819 

HOTEL15 100.0 % 70.5 759 -$24 452 -$1 624 573 -$1 252 262 -$957 451 

HIGHS02 100.0 % 165.2 1778 $619 737 -$519 066 -$1 063 139 -$1 945 659 

OFFIC03 37.4 % 65.7 707 $3 018 537 $1 884 409 $1 571 500 $360 112 

OFFIC08 40.4 % 70.8 762 $3 431 942 $2 114 500 $1 595 667 $195 169 

OFFIC16 22.2 % 39.0 419 $5367 -$263 494 -$57 242 $83 896 

RETAIL1 100.0 % 224.4 2415 $4 989 089 $1 626 047 $313 796 $1 419 893 

RSTRNT1 100.0 % 19.3 208 $1 923 956 $1 450 591 $1 139 824 -$279 970 

Total 674.5 7260 $13 966 895 $4 303 694 $1 833 322 -$1 435 249 

Note: Dormitories are excluded because no such floor area category is reported in the construction data. 

9.3 State Summary 

Kansas is one of four states in the Midwest Census Region that has not yet adopted a 

state energy code for commercial buildings, and is located in the warmest climates in the 

region. 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, but does not do 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 229.5 GWh (783.5 GBtu), energy cost savings of 

$13.9 million, and 208 374 metric tons of carbon emissions reductions at a life-cycle cost 

of $2.9 million for one year’s worth of commercial building construction. 

The adoption of the LEC design leads to savings in total 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 would lead to even greater impacts than adopting 

ASHRAE 90.1-2007, with savings of 438.6 GWh (1497.5 GBtu), $28.6 million of energy 

costs, and 436 042 metric tons of carbon emissions while decreasing life-cycle costs by 

$2.3 million for one year’s worth of commercial building construction. 

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Michigan 

10 Michigan 

Michigan is located in the East North Central Census Division and has adopted ASHRAE 

90.1-2007 as its state energy code for commercial buildings. Michigan spans three 

climate zones with the southern portion of the state located in Zone 5A, the central 

portion in Zone 6A, and the northern portion in Zone 7. Table 10-1 provides an overview 

of Michigan’s simulated energy use keyed to building types and energy codes. Average 

energy use varies across building types. 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 273 kWh/m2 to 286 kWh/m2 (87 kBtu/ft2 to 

91 kBtu/ft2) annually. 

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

Michigan 

Building 

Type 

Standard Edition 

2007 

kWh/m2 kBtu/ft2 

LEC 

kWh/m2 kBtu/ft2 

APART04 

APART06 

181 57 

179 57 

165 52 

163 52 

DORMI04 

DORMI06 

144 46 

198 63 

129 41 

181 57 

HOTEL15 191 61 172 55 

HIGHS02 286 91 273 87 

OFFIC03 

OFFIC08 

OFFIC16 

120 38 

106 34 

174 55 

100 32 

88 28 

153 48 

RETAIL1 136 43 119 38 

RSTRNT1 185 59 144 46 

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. 

10.1 Percentage Savings 

Changes in percentage terms allow for direct comparisons across building types within a 

state. This section discusses the average percentage changes from investing in the LEC 

design for the state of Michigan. 

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Michigan 

10.1.1 Statewide Building Comparison 

Table 10-2 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 -4.6 % to -22.1 % with an 

average of -12.0 % relative to the ASHRAE 90.1-2007 design. The greatest reduction in 

energy use for the LEC design occurs for the restaurant while the smallest reductions 

occur for the high school. 

Table 10-2 Average Percentage Change from Adoption of the LEC Design, 10-Year, 

Michigan 

Building LEC 

Type Energy Use Energy Cost Carbon LCC 

APART04 -8.5 -15.2 -16.3 0.4 

APART06 -8.9 -16.7 -17.9 0.3 

DORMI04 -10.7 -16.5 -17.4 -1.2 

DORMI06 -8.5 -15.9 -17.1 0.1 

HOTEL15 -10.1 -15.5 -16.4 0.2 

HIGHS02 -4.6 -12.7 -14.2 -0.8 

OFFIC03 -16.4 -21.0 -21.5 -2.6 

OFFIC08 -16.7 -19.6 -19.8 -2.2 

OFFIC16 -12.6 -16.9 -17.5 0.2 

RETAIL1 -12.6 -16.0 -16.4 -0.3 

RSTRNT1 -22.1 -30.3 -31.4 -3.0 

Average -12.0 -17.9 -18.7 -0.8 

The LEC design realizes average changes in energy costs from -12.7 % to -30.3 % 

depending on the building type, with an average of -17.9 % overall over 10 years of 

operation. The high school realizes the smallest average reduction in energy costs while 

the restaurant realizes the greatest average reduction in energy costs. For all building 

types, the reduction in energy costs is greater than the reduction in energy use because the 

energy efficiency measures decrease electricity consumption 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 most 

extreme case is the high school, which realizes a reduction in energy costs that is over 

twice as large in percentage terms as the energy use reduction. The increase in natural gas 

consumption offsets 41.3 % of the decrease in electricity consumption resulting from 

adopting the LEC design. The shift from electricity to natural gas further decreases 

energy costs, in percentage terms, because electricity is more expensive than natural gas 

in Michigan. 

The LEC design leads to average changes in carbon emissions ranging from -14.2 % 

to -31.4 % depending on the building type, with an average of -18.7 % across all building 

types. For the LEC design, the percentage reduction in carbon emissions is greater than 

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Michigan 

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 6 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 average change in life-cycle costs for the LEC design over a 10-year study period 

ranges from -3.0 % to 0.4 %. Four- and 6-story apartment buildings realize the largest 

increase in life-cycle costs while restaurants, 3-story office buildings, and 8-story office 

buildings are the building types that realize the greatest reductions in average life-cycle 

costs. Given that 6 of 11 buildings types realize an average percentage decrease in lifecycle costs, the LEC design may be cost-effective if the state adopted it as its state energy 

code for commercial buildings. 

10.1.2 City Comparisons 

Simulations are run for 9 cities in Michigan located across three climate zones: Detroit, 

Flint, Grand Rapids, Lansing, and Muskegon located in Zone 5A, Alpena and Traverse 

City located in Zone 6A, and Houghton and Sault Ste. Marie located in Zone 7. The 

results may vary across cities within Michigan for several reasons. First, the state is 

covered by 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. 

Table 13-3 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 across cities, ranging from -9.9 % to -12.6 %. 

The smallest reduction in energy use is realized by Sault Ste. Marie. Excluding Sault Ste. 

Marie, any variation across or within climate zones in Michigan appears to have minimal 

effects on energy consumption. 

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Michigan 

Table 10-3 Average Percentage Change from Adoption of the LEC Design by City, 

10- Year, Michigan 

Cities Zone LEC 

Energy Use Energy Cost Carbon LCC 

Detroit 5A -12.4 -18.9 -20.0 -0.5 

Flint 5A -12.2 -18.8 -20.0 -0.7 

Grand Rapids 5A -11.9 -18.6 -19.8 -0.9 

Lansing 5A -12.2 -18.8 -20.0 -0.9 

Muskegon 5A -12.2 -18.9 -20.1 -0.7 

Alpena 6A -12.3 -16.5 -17.3 -0.7 

Traverse City 6A -12.6 -16.6 -17.4 -0.9 

Houghton 7 -12.3 -16.4 -17.3 -0.5 

Sault Ste Marie 7 -9.9 -17.1 -18.3 -1.3 

Average -12.0 -17.9 -18.9 -0.8 

The average percentage change in energy costs for all building types also varies across 

cities, ranging from -16.4 % to -18.9 % 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. Cities located in Zone 5A realize greater reductions in energy costs 

than cities in Zone 6A and Zone 7. Repeating the pattern, the average percentage change 

in carbon emissions for all building types also varies across cities, ranging from -17.3 % 

to -20.1 %. All cities realize average percentage reductions in life-cycle costs. However, 

the percentage change in life-cycle costs varies across cities, ranging from -1.3 % 

to -0.5 %. Sault Ste. Marie realizes the greatest reduction in life-cycle costs. Excluding 

Sault Ste. Marie, there are no trends in the percentage change in life-cycle costs across 

climate zones. 

10.2 Total Savings 

How much can Michigan 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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Michigan 

10.2.1 Energy Use 

Table 10-4 reports the average per unit change in annual energy use by building type for 

the LEC design in the state.22 The reduction per m2 (ft2

) is multiplied by the estimated m2 

(ft2) of new construction of each building type, and Table 10-5 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.23 

Table 10-4 Average Per Unit Change in Annual Energy Use, Michigan 

Building Standard Edition 

Type LEC 

kWh/m2 kBtu/ft2 

APART04 -15.4 -4.9 

APART06 -15.8 -5.0 

DORMI04 -15.4 -4.9 

DORMI06 -16.8 -5.3 

HOTEL15 -19.2 -6.1 

HIGHS02 -19.6 -6.2 

OFFIC03 -13.2 -4.2 

OFFIC08 -17.7 -5.6 

OFFIC16 -21.9 -7.0 

RETAIL1 -17.1 -5.4 

RSTRNT1 -40.7 -12.9 

The annual reduction in energy use shown in Table 10-5 ranges widely across building 

types with reported floor area data, but the LEC design decreases overall energy use 

across the state for all building types. The adoption of the LEC design as the state’s 

energy code would save 28.9 GWh (98.6 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 56.4 % 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 total statewide savings to be 51.2 

GWh (174.8 GBtu) per year. These savings imply 511.9 GWh (1747.7 GBtu) in energy 

use savings over the 10-year study period. 

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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Michigan 

Table 10-5 Statewide Change in Annual Energy Use for One Year of Construction, 

Michigan 

Building Subcategory m 2 ft2 Standard Edition 

Type Weighting (1000s) (1000s) LEC 

kWh kBtu 

APART04 44.9 % 40.1 431 -615 436 -2 101 363
 

APART06 55.1 % 49.1 529 -777 709 -2 655 432
 

HOTEL15 100.0 % 142.5 1534 -2 738 428 -9 350 170 

HIGHS02 100.0 % 411.6 4430 -5 418 638 -18 501 561 

OFFIC03 37.4 % 126.9 1366 -2 492 758 -8 511 349 

OFFIC08 40.4 % 136.9 1473 -2 419 426 -8 260 961 

OFFIC16 22.2 % 75.3 811 -1 650 113 -5 634 194 

RETAIL1 100.0 % 649.1 6987 -11 128 288 -37 996 762 

RSTRNT1 100.0 % 40.0 431 -1 627 879 -5 558 278 

Total 1671.5 17 992 -28 868 675 -98 570 070 

Note: Dormitories are excluded because no such floor area category is reported in 

the construction data. 

The relative reduction in energy use varies across the 9 building types with reported floor 

area data for the LEC design relative to ASHRAE 90.1-2007. The greatest reductions are 

realized by the retail store followed by the high school. The smallest reductions are 

realized by the 4- and 6-story apartment buildings. 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 38.8 % 

and 24.6 %, respectively, of the new construction in the state while all other building 

types represent 8.5 % or less. The amount of new construction overwhelms the relative 

percentage 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. The building types that lead to the greatest estimated reduction in 

energy use -- retail stores and high schools -- only rank 4th and 11th in percentage 

reduction, respectively, among the 11 building types, as reported in Table 10-2. 

10.2.2 Energy Costs 

Table 10-6 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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Michigan 

Table 10-6 Average Per Unit Change in Energy Costs, 10-Year, Michigan
 

Building Standard Edition 

Type LEC 

$/m2 $/ft2 

APART04 -$11.99 -$1.11 

APART06 -$13.15 -$1.22 

DORMI04 -$10.65 -$0.99 

DORMI06 -$13.80 -$1.28 

HOTEL15 -$13.21 -$1.23 

HIGHS02 -$14.89 -$1.38 

OFFIC03 -$14.60 -$1.36 

OFFIC08 -$13.37 -$1.24 

OFFIC16 -$16.23 -$1.51 

RETAIL1 -$11.77 -$1.09 

RSTRNT1 -$29.71 -$2.76 

Table 10-7 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. All building types realize energy cost savings for the LEC design, with the 

energy cost savings being highly correlated with energy use savings. Any variation is a 

result of the greater percentage reduction in electricity consumption relative to the 

reduction in natural gas consumption. Overall, the reduction in energy costs totals $22.8 

million for adopting the LEC design relative to ASHRAE 90.1-2007. Assuming that the 

buildings considered in this study, which represent 56.4 % 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 

energy cost savings of $40.4 million over the 10-year study period. 

Table 10-7 Statewide Change in Energy Costs for One Year of Construction, 

10-Year, Michigan 

Building Subcategory m 2 ft2 Standard Edition
 

Type Weighting (1000s) (1000s) LEC
 

APART04 44.9 % 40.1 431 -$480 648
 

APART06 55.1 % 49.1 529 -$645 430
 

HOTEL15 100.0 % 142.5 1534 -$1 882 477 

HIGHS02 100.0 % 411.6 4430 -$6 009 073 

OFFIC03 37.4 % 126.9 1366 -$1 890 295 

OFFIC08 40.4 % 136.9 1473 -$1 829 521 

OFFIC16 22.2 % 75.3 811 -$1 222 430 

RETAIL1 100.0 % 649.1 6987 -$7 637 343 

RSTRNT1 100.0 % 40.0 431 -$1 188 431 

Total 1671.5 17 992 -$22 785 647 

Note: Dormitories are excluded because no such floor area category is 

reported in the construction data. 

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Michigan 

10.2.3 Energy-related Carbon Emissions 

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

Building Standard Edition 

Type LEC 

kg/m2 lb/ft2 

APART04 -145.6 -29.8 

APART06 -160.4 -32.9 

DORMI04 -128.0 -26.2 

DORMI06 -168.2 -34.5 

HOTEL15 -158.5 -32.5 

HIGHS02 -181.7 -37.2 

OFFIC03 -180.4 -36.9 

OFFIC08 -161.8 -33.1 

OFFIC16 -196.2 -40.2 

RETAIL1 -141.2 -28.9 

RSTRNT1 -358.5 -73.4 

Table 10-9 applies the Table 10-8 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 types, and is correlated with each building’s total reduction in energy use. 

However, there is not a perfect correlation because the magnitude of the offsetting natural 

gas increase varies across building types. The adoption of the LEC design as the state’s 

energy code decreases carbon emissions by 276 887 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 490 935 metric tons 

over the 10-year study period. 

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Michigan 

Table 10-9 Statewide Change in Total Carbon Emissions for One Year of 

Construction, 10-Year, Michigan – Metric Tons 

Building Subcategory m 2 ft2 Standard Edition
 

Type Weighting (1000s) (1000s) LEC
 

APART04 44.9 % 40.1 431 -5836
 

APART06 55.1 % 49.1 529 -7875
 

HOTEL15 100.0 % 142.5 1534 -22 592 

HIGHS02 100.0 % 411.6 4430 -74 785 

OFFIC03 37.4 % 126.9 1366 -22 892 

OFFIC08 40.4 % 136.9 1473 -22 150 

OFFIC16 22.2 % 75.3 811 -14 773 

RETAIL1 100.0 % 649.1 6987 -91 641 

RSTRNT1 100.0 % 40.0 431 -14 343 

Total 1671.5 17 992 -276 887 

Note: Dormitories are excluded because no such floor area category is 

reported in the construction data. 

10.2.4 Life-Cycle Costs 

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

Building Standard Edition 

Type LEC 

$/m2 $/ft2 

APART04 $3.86 $0.36 

APART06 $3.49 $0.32 

DORMI04 -$10.58 -$0.98 

DORMI06 $0.71 $0.07 

HOTEL15 $2.35 $0.22 

HIGHS02 -$6.81 -$0.63 

OFFIC03 -$19.89 -$1.85 

OFFIC08 -$17.17 -$1.60 

OFFIC16 $1.51 $0.14 

RETAIL1 -$1.73 -$0.16 

RSTRNT1 -$38.52 -$3.58 

Table 10-11 applies the Table 10-10 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 the LEC design. The change in life-cycle costs varies widely across building types. 

High schools realize the greatest decrease in life-cycle costs ($2.8 million) followed by 3­

and 8-story office buildings ($2.5 million and $2.4 million, respectively). The hotel 

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Michigan 

realizes the greatest increase in life-cycle costs ($335 351). Adopting the LEC design 

leads to a reduction in statewide life-cycle costs of $9.6 million relative to ASHRAE 

90.1-2007. 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 decrease in statewide life-cycle costs 

of $17.0 million over the 10-year study period. 

Table 10-11 Statewide Change in Life-Cycle Costs for One Year of Construction, 

10-Year, Michigan 

Building Subcategory m 2 ft2 Standard Edition
 

Type Weighting (1000s) (1000s)
 LEC 

APART04 44.9 % 40.1 431 $154 868 

APART06 55.1 % 49.1 529 $171 364 

HOTEL15 100.0 % 142.5 1534 $335 351 

HIGHS02 67.5 % 411.6 4430 -$2 804 667 

OFFIC03 37.4 % 126.9 1366 -$2 524 206 

OFFIC08 40.4 % 136.9 1473 -$2 350 402 

OFFIC16 22.2 % 75.3 811 $113 480 

RETAIL1 100.0 % 649.1 6987 -$1 121 682 

RSTRNT1 100.0 % 40.0 431 -$1 540 823 

Total 1671.5 17 992 -$9 566 716 

Note: Dormitories are excluded because no such floor area category is 

reported in the construction data. 

10.3 State Summary 

Michigan has adopted ASHRAE 90.1-2007 as its energy code for commercial buildings. 

The adoption of the LEC design, which goes beyond ASHRAE 90.1-2007, leads to 

reductions in energy use, energy cost, and energy-related carbon emissions 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 would lead to energy use savings of 511.9 GWh (1747.7 GBtu), energy cost savings 

of $40.4 million, and carbon emissions reductions of 490 935 metric tons while 

decreasing life-cycle costs by $17.0 million for one year’s worth of commercial building 

construction. 

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Minnesota 

11 Minnesota 

Minnesota is located in the West North Central Census Division, and spans two climate 

zones with the southern portion of the state located in Zone 6A and the northern portion 

in Zone 7. Minnesota is the only state in the Midwest Census Region that has adopted 

ASHRAE 90.1-2004 as its state energy code for commercial buildings. Table 11-1 

provides an overview of Minnesota’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 95 kWh/m2 to 121 

kWh/m2 (30 kBtu/ ft2 to 38 kBtu/ft2

) annually. The high school uses the greatest amount 

of energy at 316 kWh/m2 to 348 kWh/m2 (100 kBtu/ft2 to 110 kBtu/ft2) annually. 

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

Minnesota 

Building 

Type 

Standard Edition 

2004 2007 LEC 

kWh/m2 kBtu/ft2 kWh/m2 kBtu/ft2 kWh/m2 kBtu/ft2 

APART04 214 68 204 65 184 59 

APART06 210 67 201 64 183 58 

DORMI04 176 56 163 52 142 45 

DORMI06 230 73 221 70 204 65 

HOTEL15 209 66 214 68 194 62 

HIGHS02 348 110 336 107 316 100 

OFFIC03 143 45 130 41 105 33 

OFFIC08 121 38 114 36 95 30 

OFFIC16 187 59 193 61 171 54 

RETAIL1 175 56 155 49 127 40 

RSTRNT1 245 78 203 64 151 48 

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. 

11.1 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 Minnesota. 

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Minnesota 

11.1.1 Energy Use 

Table 11-2 shows a large variation in percentage changes in energy use for ASHRAE 

90.1-2007 relative to ASHRAE 90.1-2004, ranging from 3.0 % to -17.0 % with an average 

of -5.6 %. 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 SHGC requirement in Zone 6A and Zone 7 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 impact of this requirement relaxation enough to overwhelm the energy 

efficiency gains obtained from other measures, such as increased insulation R-values. 

Table 11-2 Average Percentage Change in Energy Use from Adoption of Newer 

Standard Editions, Minnesota 

Building Standard Edition
 

Type
 2007 LEC 

APART04 -4.9 -13.8 

APART06 -4.4 -13.0 

DORMI04 -7.3 -19.0 

DORMI06 -3.6 -11.3 

HOTEL15 2.7 -6.8 

HIGHS02 -3.4 -9.2 

OFFIC03 -9.2 -26.1 

OFFIC08 -5.6 -21.4 

OFFIC16 3.0 -8.7 

RETAIL1 -11.7 -27.3 

RSTRNT1 -17.0 -37.9 

Average -5.6 -17.7 

The LEC design realizes percentage changes in energy use relative to ASHRAE 

90.1-2004, ranging from -6.8% to -37.9 % with an average of -17.7 %. Similar to the 

ASHRAE 90.1-2007 design, the smallest reductions in energy use for the LEC design 

occur in the 16-story office building and hotel. The high school also realizes smaller 

reductions in energy use, which is driven by the seasonality of its assumed building 

occupancy. Some of the additional energy efficiency measures adopted by the LEC 

design, particularly daylighting, decrease electricity use while increasing natural gas use 

during the school year. 

11.1.2 Energy Costs 

Table 11-3 shows significant variation in the percentage changes in average energy costs 

for ASHRAE 90.1-2007 relative to ASHRAE 90.1-2004, ranging from 4.7 % to -10.1 % 

depending on the building type, with an average of -2.8 %. As with energy use savings, 

adopting ASHRAE 90.1-2007 results in an increase in energy costs relative to ASHRAE 

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Minnesota 

90.1-2004 for the two high-rise buildings. For these two building types, the percentage 

increase in energy costs is smaller than the increase in energy use because electricity 

consumption increases while decreasing natural gas consumption. The offset of natural 

gas with electricity 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 11-3 Average Percentage Change in Energy Costs, 10-Year, Minnesota 

Building Standard Edition 

Type 2007 LEC 

APART04 -3.5 -18.0 

APART06 -3.1 -17.3 

DORMI04 -4.7 -20.7 

DORMI06 -2.5 -15.2 

HOTEL15 4.7 -6.8 

HIGHS02 -2.6 -14.1 

OFFIC03 -4.3 -23.7 

OFFIC08 -2.2 -19.8 

OFFIC16 4.7 -7.8 

RETAIL1 -6.9 -23.9 

RSTRNT1 -10.1 -36.3 

Average -2.8 -18.5 

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 -6.8 % 

to -36.3 % with an overall average of -18.5 % for 10 years of building operation. The 

reductions in energy costs are greater than the reductions in energy use for 5 of 11 

building types. For these building types, electricity consumption is decreased by a greater 

percentage than natural gas consumption, which leads to additional reductions in energy 

costs. Similar to ASHRAE 90.1-2007, the remaining six building types see percentage 

reductions in energy costs that are marginally smaller than the reductions in energy use 

because adoption of the LEC design decreases natural gas consumption by a greater 

percentage than electricity consumption. 

11.1.3 Energy-related Carbon Emissions Reduction 

Table 11-4 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 

5.0 % to -9.2 % with an average of -2.4 %. The LEC design leads to significant changes 

in average carbon emissions, ranging from -6.8 % to -36.1 % depending on the building 

type with an average of -18.6 % across all building types. As would be expected, a more 

energy efficient building design results in greater reductions in carbon emissions. 

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Minnesota 

However, the 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 changes in energy costs, this result is due to the fuel source of the changes 

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 are 

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 

decreased while electricity consumption is increased. The results are mixed from 

adopting the LEC design, with five building types realizing smaller reductions and six 

building types realizing greater reductions in carbon emissions than in energy use. 

Table 11-4 Average Percentage Change in Energy-related Carbon Emissions, 10­

Year, Minnesota 

Building Standard Edition 

Type 2007 LEC 

APART04 -3.3 -18.6 

APART06 -2.9 -17.9 

DORMI04 -4.3 -20.9 

DORMI06 -2.3 -15.7 

HOTEL15 5.0 -6.8 

HIGHS02 -2.4 -14.9 

OFFIC03 -3.8 -23.4 

OFFIC08 -1.9 -19.6 

OFFIC16 4.9 -7.7 

RETAIL1 -6.3 -23.5 

RSTRNT1 -9.2 -36.1 

Average -2.4 -18.6 

11.1.4 Life-Cycle Costs 

The most cost-effective building design for each building type is bolded in Table 11-5. 

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 3 building types while the LEC design has the 

lowest life-cycle costs for 6 building types. The current state energy code, ASHRAE 

90.1-2004, results in the lowest life-cycle costs for the hotel and 16-story office building. 

For 9 building types, ASHRAE 90.1-2007 leads to percentage reductions in life-cycle 

costs. The high-rise buildings are the only buildings that realize increases in life-cycle 

costs. Given that 9 building types realize a percentage decrease in life-cycle costs, it is 

likely that adopting ASHRAE 90.1-2007 will decrease total life-cycle costs. 

The LEC design results in reductions in life-cycle costs for 6 of the 11 building types for 

a 10-year study period. The percentage change in life-cycle costs ranges from -5.0 % to 

1.0 %. Based on the overall average percentage change of -0.8 % in life-cycle costs, the 

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Minnesota 

LEC design may be cost-effective if the state adopted it as its state energy code for 

commercial buildings. 

Table 11-5 Average Percentage Change in Life-Cycle Costs, 10-Year, Minnesota 

Building Standard Edition 

Type 2007 LEC 

APART04 -0.5 0.2 

APART06 -0.4 0.4 

DORMI04 -0.7 -1.5 

DORMI06 -0.3 0.2 

HOTEL15 0.3 0.9 

HIGHS02 -0.5 -1.1 

OFFIC03 -0.5 -1.8 

OFFIC08 -0.3 -1.3 

OFFIC16 0.4 1.0 

RETAIL1 -0.3 -0.8 

RSTRNT1 -2.2 -5.0 

Average -0.4 -0.8 

11.1.5 City Comparisons 

Simulations are run for five cities located in Minnesota: Minneapolis, Rochester, and 

Saint Cloud in Zone 6A and Duluth and International Falls in Zone 7. The results may 

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 11-6, the average reduction in energy use for all building types 

from adopting newer energy standard editions is greater for Zone 7 relative to Zone 6A. 

For the ASHRAE 90.1-2007 design, the percentage change in average energy use 

averages -7.4 % in Zone 7 and -4.4 % in Zone 6A. For the LEC design, the percentage 

change in average energy use is -20.1 % in Zone 7 and -16.1 % in Zone 6A. There is 

insignificant variation in percentage changes in energy use within either climate zone. 

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Minnesota 

Table 11-6 Average Percentage Change in Energy Use from Adoption of Newer 

Standard Editions by City, Minnesota 

Cities Zone Standard Edition 

2007 LEC 

Minneapolis 6A -4.3 -16.2 

Rochester 6A -4.4 -16.2 

Saint Cloud 6A -4.4 -15.8 

Duluth 7 -7.4 -20.2 

International Falls 7 -7.4 -20.0 

Average -5.6 -17.7 

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 11-7 shows that the average 

reduction in energy costs for all building types varies across, but not within climate 

zones. For the ASHRAE 90.1-2007 design, the percentage change in average energy costs 

ranges from -1.8 % to -4.1 % with an average of -2.8 %. The average percentage change 

in energy costs are greater in Zone 7 (-4.1 %) than Zone 6A (-1.9 %). For the LEC 

design, the percentage change in average energy costs ranges from -17.7 % to -19.8 % 

with an average of -18.5 %. The colder climate zone (Zone 7) realizes slightly greater 

changes in energy use than the warmer climate zone (Zone 6A). 

Table 11-7 Average Percentage Change in Energy Costs by City, 10-Year, 

Minnesota 

Cities Zone Standard Edition 

2007 LEC 

Minneapolis 6A -1.9 -17.7 

Rochester 6A -1.8 -17.7 

Saint Cloud 6A -1.9 -17.6 

Duluth 7 -4.1 -19.8 

International Falls 7 -4.1 -19.7 

Average -2.8 -18.5 

Table 11-8 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 cities 

in Zone 7 realize slightly greater average percentage changes in carbon emissions than 

the cities in Zone 6A for both ASHRAE 90.1-2007 and the LEC design (-4.0 % 

versus -1.9 % and -20.2 % versus -18.4 %, respectively). 

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Minnesota 

Table 11-8 Average Percentage Change in Carbon Emissions by City, Minnesota
 

Cities Zone Standard Edition 

2007 LEC 

Minneapolis 6A -1.9 -18.4 

Rochester 6A -1.8 -18.3 

Saint Cloud 6A -2.0 -18.3 

Duluth 7 -3.9 -20.2 

International Falls 7 -4.0 -20.1 

Average -2.7 -19.1 

The data reported in Table 11-9 show that adoption of the ASHRAE 90.1-2007 design 

decreases life-cycle costs across all cities, with changes in life-cycle costs ranging 

minimally from -0.4 % to -0.6 %, with Zone 7 realizing slightly greater reductions in lifecycle costs than Zone 6A. The LEC design realizes the greatest reduction in life-cycle 

costs across all cities in the state. There is no significant difference between the average 

percentage changes in life-cycle costs both within and across climate zones. 

Table 11-9 Average Percentage Change in Life-Cycle Costs by City, 10-Year, 

Minnesota 

Cities Zone Standard Edition 

2007 LEC 

Minneapolis 6A -0.4 -0.7 

Rochester 6A -0.4 -0.8 

Saint Cloud 6A -0.4 -0.8 

Duluth 7 -0.5 -0.8 

International Falls 7 -0.6 -0.9 

Average -0.4 -0.8 

11.2 Total Savings 

How much can Minnesota 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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Minnesota 

11.2.1 Energy Use 

Table 11-10 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 11-11 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 

Table 11-10 Average Per Unit Change in Annual Energy Use, Minnesota 

Building Standard Edition 

Type 2007 

kWh/m2 kBtu/ft2 

LEC 

kWh/m2 kBtu/ft2 

APART04 

APART06 

-10.43 -3.31 

-9.24 -2.93 

-29.52 -9.37 

-27.47 -8.72 

DORMI04 

DORMI06 

-12.89 -4.09 

-8.49 -2.69 

-33.44 -10.61 

-26.25 -8.33 

HOTEL15 5.30 1.68 -14.37 -4.56 

HIGHS02 -13.28 -4.21 -37.41 -11.87 

OFFIC03 

OFFIC08 

OFFIC16 

-12.03 -3.81 

-6.73 -2.13 

5.51 1.75 

-32.27 -10.23 

-25.91 -8.22 

-16.60 -5.26 

RETAIL1 -20.56 -6.52 -48.16 -15.28 

RSTRNT1 -41.87 -13.28 -93.18 -29.56 

The annual reduction in energy use shown in Table 11-11 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 16.9 

GWh (57.6 GBtu) annually. ASHRAE 90.1-2007 increases total energy use for the two 

high-rise buildings and decreases total energy use for the other 7 building types with 

retail stores realizing the greatest reduction. The adoption of the LEC design as the state’s 

energy code for commercial buildings would save 48.8 GWh (166.5 GBtu) of total 

statewide energy use annually for one year’s worth of new construction for these building 

types. 

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.
 

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Minnesota 

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

Minnesota 

Building Subcategory m 2 ft2 Standard Edition 

Type Weighting (1000s) (1000s) 2007 LEC 

kWh kBtu kWh kBtu 

APART04 44.9 % 129.2 1390 -1 346 987 -4 599 192 -3 813 272 -13 020 152
 

APART06 55.1 % 158.2 1703 -1 461 445 -4 990 000 -4 346 283 -14 840 079
 

HOTEL15 100.0 % 94.6 1019 501 858 1 713 560 -1 360 271 -4 644 549 

HIGHS02 100.0 % 234.9 2529 -2 824 972 -9 645 670 -7 579 550 -25 879 842 

OFFIC03 37.4 % 122.2 1316 -1 623 750 -5 544 180 -4 572 656 -15 613 014 

OFFIC08 40.4 % 131.8 1419 -886 887 -3 028 213 -3 414 529 -11 658 671 

OFFIC16 22.2 % 72.5 781 399 320 1 363 449 -1 203 553 -4 109 448 

RETAIL1 100.0 % 427.1 4597 -8 778 852 -29 974 775 -20 566 401 -70 222 538 

RSTRNT1 100.0 % 20.4 220 -854 184 -2 916 550 -1 901 047 -6 490 991 

Total 1390.9 14 972 -16 875 897 -57 621 570 -48 757 563 -166 479 284 

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 59.7 % 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 the 

statewide savings to be 28.3 GWh (96.5 GBtu) and 81.7 GWh (278.9 GBtu) per year for 

adoption of the ASHRAE 90.1-2007 and LEC designs, respectively. These savings imply 

282.7 GWh (965.2 GBtu) and 816.7 GWh (2788.6 GBtu) in energy use savings over the 

10-year study period. 

The relative reduction in energy use across building types is consistent across building 

designs. The greatest total reductions are realized by retail stores and high schools 

because they represent 30.7 % and 16.9 %, respectively, of the new construction in the 

state while all other building types represent less than 12 %. The amount of new 

construction overwhelms the relative percentage changes in energy use. 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 9th in percentage reduction, 

respectively, among the 11 building types, as reported in Table 11-2. 

11.2.2 Energy Costs 

Table 11-12 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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Minnesota 

Table 11-12 Average Per Unit Change in Energy Costs, 10-Year, Minnesota
 

Building Standard Edition 

Type 2007 

$/m2 $/ft2 

LEC 

$/m2 $/ft2 

APART04 

APART06 

-$2.62 -$0.24 

-$2.29 -$0.21 

-$13.44 -$1.25 

-$12.86 -$1.19 

DORMI04 

DORMI06 

-$2.88 -$0.27 

-$2.04 -$0.19 

-$12.81 -$1.19 

-$12.33 -$1.15 

HOTEL15 $3.51 $0.33 -$5.17 -$0.48 

HIGHS02 -$2.84 -$0.26 -$15.54 -$1.44 

OFFIC03 

OFFIC08 

OFFIC16 

-$2.88 -$0.27 

-$1.38 -$0.13 

$3.92 $0.36 

-$15.79 -$1.47 

-$12.22 -$1.13 

-$6.50 -$0.60 

RETAIL1 -$4.94 -$0.46 -$17.14 -$1.59 

RSTRNT1 -$9.86 -$0.92 -$35.38 -$3.29 

Table 11-13 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: $3.6 million and $20.0 million for adopting 

ASHRAE 90.1-2007 and LEC, 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 59.7 % 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 ASHRAE 90.1-2007 and LEC can be extrapolated to estimate the 

total statewide energy cost savings of $6.0 million and $33.5 million over the 10-year 

study period, respectively. 

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Minnesota 

Table 11-13 Statewide Change in Energy Costs for One Year of Construction, 

10-Year, Minnesota 

Building Subcategory m 2 ft2 Standard Edition
 

Type Weighting (1000s) (1000s) 2007 LEC
 

APART04 44.9 % 129.2 1390 -$337 813 -$1 735 539 

APART06 55.1 % 158.2 1703 -$362 436 -$2 033 600 

HOTEL15 100.0 % 94.6 1019 $332 378 -$489 530 

HIGHS02 100.0 % 234.9 2529 -$677 586 -$3 710 447 

OFFIC03 37.4 % 122.2 1316 -$347 673 -$1 899 802 

OFFIC08 40.4 % 131.8 1419 -$181 402 -$1 610 264 

OFFIC16 22.2 % 72.5 781 $284 396 -$471 054 

RETAIL1 100.0 % 427.1 4597 -$2 110 264 -$7 320 168 

RSTRNT1 100.0 % 20.4 220 -$201 063 -$721 740 

Total 1390.9 14 972 -$3 601 463 -$19 992 143 

Note: Dormitories are excluded because no such floor area category is reported in the construction 

11.2.3 Energy-related Carbon Emissions 

Table 11-14 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 11-14 Average Per Unit Change in Carbon Emissions, 10-Year, Minnesota 

Building Standard Edition 

Type 2007 

kg/m2 lb/ft2 

LEC 

kg/m2 lb/ft2 

APART04 

APART06 

-31.9 -6.5 

-27.9 -5.7 

-180.3 -36.9 

-173.0 -35.4 

DORMI04 

DORMI06 

-34.3 -7.0 

-24.7 -5.1 

-168.3 -34.5 

-166.0 -34.0 

HOTEL15 48.8 10.0 -67.4 -13.8 

HIGHS02 -34.9 -7.1 -213.6 -43.7 

OFFIC03 

OFFIC08 

OFFIC16 

-33.4 -6.8 

-16.0 -3.3 

54.7 11.2 

-206.3 -42.3 

-164.5 -33.7 

-85.6 -17.5 

RETAIL1 -59.7 -12.2 -222.9 -45.6 

RSTRNT1 -118.6 -24.3 -464.2 -95.1 

Table 11-15 applies the Table 11-14 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 

42 263 metric tons over a 10-year study period. The adoption of the LEC design 

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Minnesota 

decreases carbon emissions by 264 972 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 

70 792 metric tons and 443 839 metric tons over the 10-year study period, respectively. 

Table 11-15 Statewide Change in Total Carbon Emissions for One Year of 

Construction, 10-Year, Minnesota – Metric Tons 

Building Subcategory m 2 ft2 Standard Edition
 

Type Weighting (1000s) (1000s)
 2007 LEC 

APART04 44.9 % 129.2 1390 -4124 -23 286
 

APART06 55.1 % 158.2 1703 -4413 -27 368
 

HOTEL15 100.0 % 94.6 1019 4614 -6376 

HIGHS02 100.0 % 234.9 2529 -8188 -50 171
 

OFFIC03 37.4 % 122.2 1316 -4084 -25 221
 

OFFIC08 40.4 % 131.8 1419 -2104 -21 689
 

OFFIC16 22.2 % 72.5 781 3968 -6206
 

RETAIL1 100.0 % 427.1 4597 -25 514 -95 186
 

RSTRNT1 100.0 % 20.4 220 -2419 -9471 

Total 1390.9 14 972 -42 263 -264 972
 

Note: Dormitories are excluded because no such floor area category is 

reported in the construction data. 

11.2.4 Life-Cycle Costs 

Table 11-16 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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Minnesota 

Table 11-16 Average Per Unit Change in Life-Cycle Costs, 10-Year, Minnesota
 

Building Standard Edition 

Type 2007 

$/m2 $/ft2 

LEC 

$/m2 $/ft2 

APART04 

APART06 

-$5.29 -$0.49 

-$4.01 -$0.37 

$2.15 

$4.33 

$0.20 

$0.40 

DORMI04 

DORMI06 

-$7.17 -$0.67 

-$2.94 -$0.27 

-$15.48 

$2.63 

-$1.44 

$0.24 

HOTEL15 $3.60 $0.33 $9.46 $0.88 

HIGHS02 -$5.11 -$0.47 -$10.02 -$0.93 

OFFIC03 

OFFIC08 

OFFIC16 

-$3.93 -$0.36 

-$2.80 -$0.26 

$3.44 $0.32 

-$15.86 

-$11.96 

$8.60 

-$1.47 

-$1.11 

$0.80 

RETAIL1 -$2.15 -$0.20 -$5.97 -$0.56 

RSTRNT1 -$31.64 -$2.94 -$72.36 -$6.72 

Table 11-17 applies the Table 11-16 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 $4.3 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 $7.4 million, while reducing life-cycle costs 

for 5 of 9 building types. The ASHRAE 90.1-2007 and the LEC designs both lead to an 

increase in life-cycle costs for hotels and 16-story office buildings. The LEC design also 

increases life-cycle costs for the 4- and 6-story apartment 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 

$7.3 million and $12.4 million over the 10-year study period, respectively. 

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Minnesota 

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

10-Year, Minnesota 

Building Subcategory m 2 ft2 Standard Edition
 

Type Weighting (1000s) (1000s) 2007 LEC
 

APART04 44.9 % 129.2 1390 -$683 726 $277 532 

APART06 55.1 % 158.2 1703 -$635 097 $684 399 

HOTEL15 100.0 % 94.6 1019 $340 966 $895 302 

HIGHS02 100.0 % 234.9 2529 -$1 200 196 -$2 353 524 

OFFIC03 37.4 % 122.2 1316 -$479 885 -$1 938 169 

OFFIC08 40.4 % 131.8 1419 -$369 390 -$1 576 187 

OFFIC16 22.2 % 72.5 781 $249 115 $623 993 

RETAIL1 100.0 % 427.1 4597 -$919 484 -$2 551 579 

RSTRNT1 100.0 % 20.4 220 -$645 441 -$1 476 209 

Total 1390.9 14 972 -$4 343 137 -$7 414 442 

Note: Dormitories are excluded because no such floor area category is reported in the 

construction data. 

11.3 State Summary 

Minnesota is the only state in the Midwest Census Region that has adopted ASHRAE 

90.1-2004 as its current state energy code for commercial buildings. On average, 

adopting ASHRAE 90.1-2007 leads to reductions in energy use, energy costs, and energyrelated carbon emissions. 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 282.7 GWh (965.2 GBtu), energy cost 

savings of $6.0 million, carbon emissions reductions of 70 792 metric tons, and life-cycle 

cost savings of $7.3 million. The life-cycle cost savings are greater than the energy cost 

savings. The relaxation of the SHGC requirement 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 with savings of 816.7 GWh (2788.6 

GBtu), energy cost savings of $33.5 million, and carbon emissions reductions of 443 839 

metric tons for one year’s worth of commercial building construction while decreasing 

life-cycle costs by $12.4 million. 

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Missouri 

12 Missouri 

Missouri is located in the West North Central Census Division, and spans the warmest 

climate zones in the Midwest Census Region (Zone 4 and Zone 5). 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 12-1 provides 

an overview of Missouri’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 84 kWh/m2 to 124 kWh/m2 

(27 kBtu/ft2 to 39 kBtu/ft2) annually. The high school uses the greatest amount of energy 

at 200 kWh/m2 to 234 kWh/m2 (64 kBtu/ft2 to 74 kBtu/ft2) annually. 

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

Missouri 

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 

188 60 

187 59 

187 59 

185 59 

164 52 

162 51 

158 50 

157 50 

140 45 

137 43 

DORMI04 

DORMI06 

145 46 

205 65 

142 45 

199 63 

125 40 

175 55 

120 38 

172 55 

105 33 

151 48 

HOTEL15 173 55 171 54 152 48 160 51 138 44 

HIGHS02 234 74 233 74 226 72 217 69 200 64 

OFFIC03 

OFFIC08 

OFFIC16 

133 42 

124 39 

157 50 

130 41 

121 38 

156 49 

121 38 

111 35 

147 47 

113 36 

104 33 

156 49 

90 29 

84 27 

131 42 

RETAIL1 151 48 149 47 135 43 121 38 103 33 

RSTRNT1 209 66 203 64 185 59 174 55 126 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. 

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 more energy efficient designs for the state of Missouri. 

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Missouri 

12.1.1 Energy Use 

Table 12-2 shows 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 2.0 % or less. 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 -3.4 % to -14.2 % with 

an average of -10.3 %. The average change in energy use from constructing buildings 

using ASHRAE 90.1-2007 requirements ranges from -0.7 % to -19.5 %, with an overall 

average of -13.2 %. 

Table 12-2 Average Percentage Change in Energy Use from Adoption of Newer 

Standard Editions, Missouri 

Building Standard Edition 

Type 2001 2004 2007 LEC 

APART04 -0.6 -12.9 -16.0 -25.4 

APART06 -0.6 -13.1 -15.7 -26.5 

DORMI04 -1.7 -12.9 -16.9 -27.4 

DORMI06 -2.0 -14.2 -15.4 -26.0 

HOTEL15 -0.8 -11.8 -7.3 -19.8 

HIGHS02 -0.3 -3.4 -7.1 -14.3 

OFFIC03 -1.7 -8.2 -14.8 -31.6 

OFFIC08 -2.0 -9.9 -16.1 -32.3 

OFFIC16 -0.8 -6.0 -0.7 -16.3 

RETAIL1 -1.2 -9.9 -19.5 -31.3 

RSTRNT1 -2.0 -10.9 -16.3 -39.1 

Average -1.2 -10.3 -13.2 -26.4 

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 4 and Zone 5 is increased from ASHRAE 

90.1-2004 to ASHRAE 90.1-2007, making the requirement less strict. Additionally, the 

maximum U-factor is relaxed for Zone 4. The 100 % glazing amplifies the impact of 

these requirement relaxations 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 -14.3 % to -39.1 % with an average 

of -26.4 %. 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 ratio. 

Additionally, the high school realizes smaller reductions in energy use because of its 

unique occupant activity, with significant occupancy during the school year and minimal 

occupancy during the summer. 

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Missouri 

12.1.2 Energy Costs 

Table 12-3 shows minimal change in energy costs over 10 years from adopting ASHRAE 

90.1-2001 (-0.4 % to -2.4 %), 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 -6.4 % to -20.4 % depending on the building type, 

with an average of -14.6 %. The average change in energy costs from constructing 

buildings using ASHRAE 90.1-2007 requirements ranges from -1.7 % to -22.6 %, with an 

overall average of -16.1 %. The LEC design realizes the greatest change in energy costs, 

with the average change by building type ranging from -20.0 % to -43.9 % with an 

average of -31.9 % overall. 

Table 12-3 Average Percentage Change in Energy Costs, 10-Year, Missouri 

Building Standard Edition 

Type 2001 2004 2007 LEC 

APART04 -0.7 -19.2 -21.6 -33.3 

APART06 -0.7 -19.3 -21.2 -35.2 

DORMI04 -2.0 -20.0 -22.6 -35.0 

DORMI06 -2.4 -20.4 -21.3 -34.9 

HOTEL15 -0.9 -17.9 -12.4 -27.5 

HIGHS02 -0.4 -6.4 -9.4 -21.7 

OFFIC03 -1.8 -10.2 -14.2 -33.4 

OFFIC08 -2.1 -11.5 -14.8 -32.5 

OFFIC16 -0.9 -7.9 -1.7 -20.0 

RETAIL1 -1.3 -13.4 -19.9 -33.5 

RSTRNT1 -2.3 -14.7 -18.2 -43.9 

Average -1.4 -14.6 -16.1 -31.9 

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 can decrease 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. 

12.1.3 Energy-related Carbon Emissions 

Minimal change in energy use leads to small changes (2.6 % or less) in cradle-to-grave 

energy-related carbon emissions for the ASHRAE 90.1-2001 design across all building 

types. Table 12-4 shows a significant change in average energy-related carbon emissions 

for ASHRAE 90.1-2004 for all building types, ranging from -8.9 % to -24.6 % with an 

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Missouri 

average of -17.5 %. 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 -2.3 % to -26.3 % with an overall average of -18.0 %. The LEC design leads to the 

greatest average carbon emissions changes, ranging from -22.2 % to -46.8 % depending 

on the building type with an average of -35.6 % across all building types. 

Table 12-4 Average Percentage Change in Energy-related Carbon Emissions, 10­

Year, Missouri 

Building Standard Edition 

Type 2001 2004 2007 LEC 

APART04 -0.8 -23.4 -25.3 -38.6 

APART06 -0.8 -23.4 -24.9 -40.9 

DORMI04 -2.2 -24.6 -26.3 -39.8 

DORMI06 -2.6 -24.5 -25.2 -40.6 

HOTEL15 -1.0 -21.9 -15.8 -32.6 

HIGHS02 -0.5 -8.9 -11.2 -27.7 

OFFIC03 -1.9 -11.4 -13.9 -34.4 

OFFIC08 -2.2 -12.3 -14.1 -32.6 

OFFIC16 -1.0 -9.1 -2.3 -22.2 

RETAIL1 -1.5 -15.6 -20.1 -34.8 

RSTRNT1 -2.5 -17.0 -19.3 -46.8 

Average -1.5 -17.5 -18.0 -35.6 

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. In the most extreme cases, there is a shift from electricity to natural gas 

consumption, which further decreases carbon emissions because electricity has a higher 

carbon emissions rate per unit of energy than natural gas in Missouri. 

12.1.4 Life-Cycle Costs 

The most cost-effective building design for each building type is bolded in Table 12-5. 

Life-cycle costs increase for the ASHRAE 90.1-2001 design compared to ASHRAE 

90.1-1999 for 10 of 11 building types over a 10-year study period. ASHRAE 90.1-1999 is 

the lowest cost building design for three building types while ASHRAE 90.1-2004 and 

ASHRAE 90.1-2007 are the lowest cost building design for two and three building types, 

respectively. The change in life-cycle costs for ASHRAE 90.1-2004 and -2007 range 

from -2.3 % to 5.7 % depending on building type. The LEC design realizes a reduction in 

life-cycle costs for 3 of 11 building types, with the percentage change in life-cycle costs 

ranging from -3.3 % to 1.7 %. Given that the adoption of the LEC design decreases lifecycle costs for 6 of 11 building types, it may be cost-effective to adopt the LEC design as 

the state’s energy code for commercial buildings. 

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Missouri 

Table 12-5 Average Percentage Change in Life-Cycle Costs, 10-Year, Missouri 

Building Standard Edition 

Type 2001 2004 2007 LEC 

APART04 0.1 -1.5 -1.8 -1.0 

APART06 0.0 -1.6 -1.8 -1.1 

DORMI04 3.9 0.4 -0.1 0.2 

DORMI06 -0.2 -2.2 -2.3 -1.9 

HOTEL15 0.0 -2.1 -1.6 -0.9 

HIGHS02 0.2 -0.5 -0.9 -1.4 

OFFIC03 5.4 3.5 3.0 1.4 

OFFIC08 5.6 3.4 2.4 0.4 

OFFIC16 0.1 -0.7 -0.1 0.9 

RETAIL1 3.1 1.1 0.5 1.7 

RSTRNT1 7.1 5.7 4.6 -3.3 

Average 2.3 0.5 0.2 -0.5 

12.1.5 City Comparisons 

Simulations are run for four cities located in Missouri: Columbia, Kansas City, 

Springfield, and St. Louis in Climate Zone 4. While the four cities in Missouri selected 

for this study are located in the same climate zone, the results may still vary across cities 

within the state for three 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. Finally, 

St. Louis has adopted a more stringent energy code than the state. 

As can be seen in Table 12-6, the average reduction in energy use for all building types 

from adopting newer energy standard editions varies across cities. St. Louis realizes 

smaller percentage reductions in energy use than the other three cities because St. Louis 

has adopted ASHRAE 90.1-2001 while the state has not yet adopted a state energy code. 

Excluding St. Louis, there is minimal variation between cities. For the LEC design, the 

change in average energy use ranges from -26.2 % to -27.7 %. 

Table 12-6 Average Percentage Change in Energy Use from Adoption of Newer 

Standard Editions by City, Missouri 

Cities Zone Standard Edition 

2001 2004 2007 LEC 

Columbia 4A -1.6 -10.4 -13.5 -26.5 

Kansas City 4A -1.6 -10.3 -13.2 -26.2 

Springfield 4A -1.7 -11.5 -14.3 -27.7 

St. Louis 4A 0.0 -9.0 -12.0 -25.1 

Average -1.2 -10.3 -13.2 -26.4 

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Missouri 

The variations in energy costs across cities are a result of three factors, the reduction in 

energy use, the fuel source of the reduction, and the current local energy code. Table 12-7 

shows that the average reduction in energy costs for all building types varies minimally 

across cities, with St. Louis realizing smaller reductions than the other three cities. 

Excluding St. Louis, adopting the LEC design results in an average change in energy 

costs ranging from -31.8 % to -33.1 %. 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. 

Table 12-7 Average Percentage Change in Energy Costs by City, 10-Year, Missouri 

Cities Zone Standard Edition 

2001 2004 2007 LEC 

Columbia 4A -1.9 -14.9 -16.5 -32.2 

Kansas City 4A -1.9 -14.7 -16.2 -31.8 

Springfield 4A -1.9 -15.7 -17.1 -33.1 

St. Louis 4A 0.0 -13.2 -14.7 -30.6 

Average -1.4 -14.6 -16.1 -31.9 

Table 12-8 reports changes in energy-related carbon emissions by city for Missouri. For 

all four cities, the more stringent standard editions result in greater reductions in carbon 

emissions. The percentage change in carbon emissions is greater than the percentage 

change in energy use because electricity consumption is decreased by a greater 

percentage than natural gas consumption. As with energy use and energy costs, St. Louis 

realizes smaller reductions in carbon emissions than the other three cities because the city 

has adopted ASHRAE 90.1-2001 as its local energy code. 

Table 12-8 Average Percentage Change in Carbon Emissions by City, 10-Year, 

Missouri 

Cities Zone Standard Edition 

2001 2004 2007 LEC 

Columbia 4A -1.9 -17.6 -18.6 -36.5 

Kansas City 4A -1.8 -17.1 -18.1 -35.9 

Springfield 4A -1.9 -16.9 -17.8 -35.4 

St. Louis 4A 0.0 -15.4 -16.4 -34.3 

Average -1.4 -16.7 -17.7 -35.5 

The data reported in Table 12-9 show that, over a 10-year period, average life-cycle costs 

increase for all cities for the ASHRAE 90.1-2001 compared to ASHRAE 90.1-1999. St. 

Louis realizes percentage reductions in life-cycle costs while the other three cities realize 

increases in life-cycle costs for ASHRAE 90.1-2004 and -2007. Kansas City is the only 

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Missouri 

city that does not realize a percentage reduction in life-cycle costs from adoption of the 

LEC design. Based on these results, there is significant variation in life-cycle costs across 

cities in Missouri. 

Table 12-9 Average Percentage Change in Life-Cycle Costs by City, 10-Year, 

Missouri 

Cities Zone Standard Edition 

2001 2004 2007 LEC 

Columbia 4A 3.1 1.2 0.8 -0.1 

Kansas City 4A 3.1 1.4 1.1 0.5 

Springfield 4A 3.0 1.0 0.8 -0.1 

St. Louis 4A 0.0 -1.6 -1.9 -2.0 

Average 2.3 0.5 0.2 -0.5 

12.2 Total Savings 

How much can Missouri 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 12-10 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 12-11 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.27 

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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Missouri 

Table 12-10 Average Per Unit Change in Annual Energy Use, Missouri
 

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 

-1.1 -0.4 

-1.1 -0.4 

-24.2 -7.7 

-24.3 -7.7 

-30.0 -9.5 

-29.1 -9.2 

-47.6 -15.1 

-49.3 -15.6 

DORMI04 

DORMI06 

-2.5 -0.8 

-4.1 -1.3 

-18.5 -5.9 

-28.8 -9.1 

-24.3 -7.7 

-31.3 -9.9 

-39.4 -12.5 

-52.8 -16.8 

HOTEL15 -1.3 -0.4 -20.2 -6.4 -12.6 -4.0 -34.1 -10.8 

HIGHS02 -0.7 -0.2 -10.8 -3.4 -19.5 -6.2 -41.8 -13.3 

OFFIC03 

OFFIC08 

OFFIC16 

-2.2 -0.7 

-2.4 -0.8 

-1.3 -0.4 

-8.0 -2.5 

-12.2 -3.9 

-9.5 -3.0 

-16.5 -5.2 

-19.9 -6.3 

-1.1 -0.3 

-33.3 -10.6 

-40.0 -12.7 

-25.5 -8.1 

RETAIL1 -1.8 -0.6 -14.8 -4.7 -29.3 -9.3 -47.1 -14.9 

RSTRNT1 -4.2 -1.3 -22.7 -7.2 -33.7 -10.7 -81.1 -25.7 

The total annual reduction in energy use ranges widely across building designs, but 

ASHRAE 90.1-2001, ASHRAE 90.1-2004, ASHRAE 90.1-2007, and LEC all decrease 

energy use across the state for all building types. Adopting ASHRAE 90.1-2001, ASHRAE 

90.1-2004, and ASHRAE 90.1-2007 results in an annual decrease of 2.2 GWh (7.4 GBtu), 

21.3 GWh (72.7 GBtu), and 32.3 GWh (110.4 GBtu), respectively. The adoption of the 

LEC design as the state’s energy code would save 60.8 GWh (207.4 GBtu) of total 

energy use annually for one year’s worth of new construction for these building types. 

Table 12-11 Statewide Change in Annual Energy Use for One Year of Construction, 

Missouri 

Building 

Type 

Subcat. 

Weight. m 2 

(1000s) 

ft2 

(1000s) 

Standard Edition 

2001 

MWh MBtu 

2004 

MWh MBtu 

2007 

MWh MBtu 

LEC 

MWh kBtu 

APART04 

APART06 

44.9 % 

55.1 % 

79 

96 

847 

1037 

-88 -300 

-110 -374 

-1906 -6507 

-2340 -7991 

-2364 -8071 

-2805 -9578 

-3748 -12 796 

-4750 -16 217 

HOTEL15 100.0 % 176 1897 -235 -804 -3564 -12 169 -2213 -7556 -6012 -20 526 

HIGHS02 100.0 % 325 3499 -221 -754 -2592 -8851 -5352 -18 275 -10 827 -36 968 

OFFIC03 

OFFIC08 

OFFIC16 

37.4 % 

40.4 % 

22.2 % 

92 

99 

54 

988 

1065 

586 

-203 -693 

-240 -818 

-68 -233 

-988 -3375 

-1207 -4120 

-515 -1758 

-1791 -6114 

-1966 -6711 

-58 -197 

-3836 -13 097 

-3954 -13 501 

-1390 -4745 

RETAIL1 100.0 % 503 5411 -883 -3016 -7464 -25 487 -14 720 -50 262 -23 671 -80 824 

RSTRNT1 100.0 % 32 341 -132 -452 -718 -2451 -1067 -3644 -2570 -8774 

Total 1456 15 671 -2180 -7443 -21 295 -72 710 -32 336 -110 408 -60 756 -207 448 

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 61.7 % 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 the total 

statewide savings from adopting the LEC design in new commercial buildings to be 98.5 

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Missouri 

GWh (336.2 GBtu) per year. These savings imply 984.7 GWh (3362.2 GBtu) in energy 

use savings over the 10-year study period. In comparison, ASHRAE 90.1-2007 would 

save 52.4 GWh (178.9 GBtu) annually or 524.1 GWh (1789.4 GBtu) over the 10-year 

study period. 

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 greatest total reductions are realized by retail stores 

and high schools because they represent 34.5 % and 22.3 %, respectively, of the new 

construction in the state while all other building types represent 12.1 % or less. The 

amount of new construction overwhelms the relative percentage 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 high schools -- rank 4th and 11th in percentage 

reduction, respectively, among the 11 building types, as reported in Table 12-2. 

12.2.2 Energy Costs 

Table 12-12 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 12-12 Average Per Unit Change in Energy Costs, 10-Year, Missouri 

Building Standard Edition 

Type 2001 

$/m2 $/ft2 

2004 

$/m2 $/ft2 

2007 

$/m2 $/ft2 

LEC 

$/m2 $/ft2 

APART04 

APART06 

-$0.63 

-$0.64 

-$0.06 

-$0.06 

-$17.07 

-$17.10 

-$1.59 

-$1.59 

-$19.14 

-$18.80 

-$1.78 

-$1.75 

-$29.58 

-$31.15 

-$2.75 

-$2.89 

DORMI04 

DORMI06 

-$1.39 

-$2.31 

-$0.13 

-$0.21 

-$13.89 

-$19.90 

-$1.29 

-$1.85 

-$15.70 

-$20.77 

-$1.46 

-$1.93 

-$24.23 

-$33.92 

-$2.25 

-$3.15 

HOTEL15 -$0.76 -$0.07 -$14.44 -$1.34 -$10.05 -$0.93 -$22.23 -$2.07 

HIGHS02 -$1.25 -$0.12 -$6.91 -$0.64 -$9.61 -$0.89 -$22.61 -$2.10 

OFFIC03 

OFFIC08 

OFFIC16 

-$0.38 

-$1.37 

-$0.71 

-$0.04 

-$0.13 

-$0.07 

-$6.32 

-$7.52 

-$6.26 

-$0.59 

-$0.70 

-$0.58 

-$9.21 

-$9.71 

-$1.35 

-$0.86 

-$0.90 

-$0.13 

-$21.36 

-$21.32 

-$15.78 

-$1.98 

-$1.98 

-$1.47 

RETAIL1 -$0.99 -$0.09 -$9.94 -$0.92 -$14.69 -$1.36 -$24.78 -$2.30 

RSTRNT1 -$2.36 -$0.22 -$15.09 -$1.40 -$18.66 -$1.73 -$45.10 -$4.19 

Table 12-13 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 the smallest 

reductions in energy costs ($1.2 million). ASHRAE 90.1-2004, ASHRAE 90.1-2007, and 

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Missouri 

the LEC design realize decreases in energy costs of $14.8 million, $18.0 million, and 

$35.1 million, respectively. Assuming that the buildings considered in this study, which 

represent 61.7 % 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 

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 $2.0 million, 

$24.0 million, $29.1 million, and $56.9 million over the 10-year study period, 

respectively. 

Table 12-13 Statewide Change in Energy Costs for One Year of Construction, 

10-Year, Missouri 

Building Subcategory m 2 ft2 Standard Edition 

Type Weighting (1000s) (1000s) 2001 2004 2007 LEC 

APART04 44.9 % 79 847 -$49 689 -$1 342 647 -$1 506 136 -$2 326 931
 

APART06 55.1 % 96 1037 -$61 995 -$1 648 000 -$1 811 493 -$3 001 945
 

HOTEL15 100 % 176 1897 -$133 295 -$2 544 720 -$1 770 554 -$3 916 929 

HIGHS02 100 % 325 3499 -$124 941 -$2 055 636 -$2 995 639 -$6 943 063 

OFFIC03 37.4 % 92 988 -$114 895 -$634 646 -$881 699 -$2 075 268 

OFFIC08 40.4 % 99 1065 -$135 661 -$743 870 -$961 260 -$2 109 782 

OFFIC16 22.2 % 54 586 -$38 666 -$340 987 -$73 316 -$859 483 

RETAIL1 100 % 503 5411 -$500 050 -$4 999 133 -$7 384 263 -$12 458 820 

RSTRNT1 100 % 32 341 -$74 884 -$478 143 -$591 193 -$1 428 657 

Total 1456 15 671 -$1 234 075 -$14 787 783 -$17 975 554 -$35 120 878 

Note: Dormitories are excluded because no such floor area category is reported in the construction data. 

12.2.3 Energy-related Carbon Emissions 

Table 12-14 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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Missouri 

Table 12-14 Average Per Unit Change in Carbon Emissions, 10-Year, Missouri
 

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 

-2.3 -326.0 

-2.3 -326.7 

-66.8 -351.6 

-66.9 -347.2 

-72.0 -537.3 

-71.1 -570.3 

-110.0 -2.3 

-116.8 -2.3 

DORMI04 

DORMI06 

-5.0 -271.1 

-8.2 -377.6 

-55.5 -289.8 

-77.3 -388.1 

-59.4 -438.0 

-79.5 -625.0 

-89.7 -5.0 

-128.0 -8.2 

HOTEL15 -2.7 -277.2 -56.8 -200.3 -41.0 -412.1 -84.4 -2.7 

HIGHS02 -1.4 -125.7 -25.7 -159.4 -32.6 -393.3 -80.6 -1.4 

OFFIC03 

OFFIC08 

OFFIC16 

-4.5 -127.4 

-4.9 -136.1 

-2.5 -116.8 

-26.1 -154.7 

-27.9 -155.7 

-23.9 -29.9 

-31.7 -384.3 

-31.9 -359.6 

-6.1 -286.2 

-78.7 -4.5 

-73.7 -4.9 

-58.6 -2.5 

RETAIL1 -3.5 -186.4 -38.2 -239.2 -49.0 -415.0 -85.0 -3.5 

RSTRNT1 -8.4 -282.3 -57.8 -321.1 -65.8 -777.5 -159.2 -8.4 

Table 12-15 applies the Table 12-14 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 90.1-2001, 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 281 003 metric tons 

and 309 899 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 617 379 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 455 435 metric tons, 502 267 metric tons, 

and 1.0 million metric tons over the 10-year study period, respectively. 

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Missouri 

Table 12-15 Statewide Change in Total Carbon Emissions for One Year of 

Construction, 10-Year, Missouri – Metric Tons 

Building Subcategory m 2 ft2 Standard Edition 

Type Weighting (1000s) (1000s) 2001 2004 2007 LEC 

APART04 44.9 % 79 847 -865 -25 649 -27 663 -42 269 

APART06 55.1 % 96 1037 -1079 -31 477 -33 457 -54 949 

HOTEL15 100.0 % 176 1897 -2319 -48 849 -35 299 -72 608 

HIGHS02 100.0 % 325 3499 -2174 -40 868 -51 824 -127 864 

OFFIC03 37.4 % 92 988 -1999 -11 694 -14 195 -35 273 

OFFIC08 40.4 % 99 1065 -2360 -13 470 -15 411 -35 593 

OFFIC16 22.2 % 54 586 -673 -6 362 -1629 -15 586 

RETAIL1 100.0 % 503 5411 -8700 -93 691 -120 247 -208 604 

RSTRNT1 100.0 % 32 341 -1303 -8942 -10 174 -24 632 

Total 1456 15 671 -21 471 -281 003 -309 899 -617 379 

Note: Dormitories are excluded because no such floor area category is reported in the 

construction data. 

12.2.4 Life-Cycle Costs 

Table 12-16 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 12-16 Average Per Unit Change in Life-Cycle Costs, 10-Year, Missouri 

Building Standard Edition 

Type 2001 

$/m2 $/ft2 

2004 

$/m2 $/ft2 

2007 

$/m2 $/ft2 

LEC 

$/m2 $/ft2 

APART04 $0.55 $0.05 -$16.07 -$1.49 -$19.03 -$1.77 -$10.21 -$0.95 

APART06 $0.08 $0.01 -$16.75 -$1.56 -$19.11 -$1.77 -$11.77 -$1.09 

DORMI04 $38.49 $3.58 $3.35 $0.31 -$2.32 -$0.22 $1.60 $0.15 

DORMI06 -$1.77 -$0.16 -$23.95 -$2.23 -$24.97 -$2.32 -$20.84 -$1.94 

HOTEL15 $0.05 $0.00 -$21.16 -$1.97 -$16.43 -$1.53 -$9.11 -$0.85 

HIGHS02 $1.73 $0.16 -$4.08 -$0.38 -$7.48 -$0.69 -$11.64 -$1.08 

OFFIC03 $43.13 $4.01 $27.71 $2.57 $23.85 $2.22 $10.53 $0.98 

OFFIC08 $46.97 $4.36 $27.98 $2.60 $19.01 $1.77 $1.97 $0.18 

OFFIC16 $0.55 $0.05 -$5.24 -$0.49 -$0.65 -$0.06 $7.27 $0.68 

RETAIL1 $21.23 $1.97 $7.12 $0.66 $2.95 $0.27 $11.19 $1.04 

RSTRNT1 $97.27 $9.04 $78.27 $7.27 $62.20 $5.78 -$48.30 -$4.49 

Table 12-17 applies the Table 12-16 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 

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Missouri 

the ASHRAE 90.1-2001 design results in an increase in life-cycle costs for all 9 building 

types and increases total statewide life-cycle costs by $23.0 million. The ASHRAE 

90.1-2004 and -2007 designs result in a decrease in life-cycle costs for 5 of 9 building 

types, with total life-cycle costs increasing by $3.1 million for ASHRAE 90.1-2004 and 

decreasing by $1.2 million for ASHRAE 90.1-2007. The LEC design decreases life-cycle 

costs for 5 of 9 building types, and decreases total life-cycle costs by $1.7 million. The 

results for the ASHRAE 90.1-2007 design emphasize the importance of estimating total 

statewide impacts instead of focusing on the average percentage change in life-cycle 

costs, because total life-cycle costs are decreased even though the average percentage 

change in life-cycle costs is positive. 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 $37.3 million, 

$5.1 million, -$1.9 million, and -$2.7 million over the 10-year study period, respectively. 

Table 12-17 Statewide Change in Life-Cycle Costs for One Year of Construction, 

10-Year, Missouri 

Building Subcategory m 2 ft2 Standard Edition 

Type Weighting (1000s) (1000s) 2001 2004 2007 LEC 

APART04 44.9 % 79 847 $42 962 -$1 264 632 -$1 496 810 -$803 128
 

APART06 55.1 % 96 1037 $7682 -$1 614 481 -$1 840 983 -$1 134 155
 

HOTEL15 100.0 % 176 1897 $8902 -$3 728 180 -$2 894 223 -$1 604 607 

HIGHS02 100.0 % 325 3499 $560 832 -$1 327 736 -$2 431 676 -$3 785 260 

OFFIC03 37.4 % 92 988 $3 958 308 $2 543 076 $2 188 712 $966 702 

OFFIC08 40.4 % 99 1065 $4 648 800 $2 769 010 $1 881 288 $194 621 

OFFIC16 22.2 % 54 586 $29 749 -$285 436 -$35 536 $396 073 

RETAIL1 100.0 % 503 5411 $10 674 089 $3 576 708 $1 481 402 $5 624 263 

RSTRNT1 100.0 % 32 341 $3 081 362 $2 479 703 $1 970 535 -$1 530 097 

Total 1456 15 671 $23 012 686 $3 148 032 -$1 177 291 -$1 675 588 

Note: Dormitories are excluded because no such floor area category is reported in the construction data. 

12.3 State Summary 

Missouri is one of the four states in the Midwest Census Region that has no state energy 

code for commercial buildings, and represents the warmest climates in the Midwest 

Census Region. Adopting the ASHRAE 90.1-2001 and -2004 designs 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, costing $37.3 million and $5.1 million over 10 

years, respectively. On average, adopting the ASHRAE 90.1-2007 and LEC designs leads 

to reductions in energy use, energy costs, and cradle-to-grave energy-related carbon 

emissions 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 

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Missouri 

ASHRAE 90.1-2007 as the state’s energy code for commercial buildings would lead to 

energy use savings of 524.1GWh (1789.4 GBtu), energy cost savings of $29.1 million, 

and 502 267 metric tons of carbon emissions reductions while saving $1.9 million in lifecycle costs for one year’s worth of commercial building construction. Adopting the LEC 

design would lead to even greater impacts than adopting ASHRAE 90.1-2007, with 

savings of 984.7 GWh (3362.2 GBtu), $56.9 million of energy costs, 1.0 million metric 

tons of carbon emissions while decreasing life-cycle costs by $2.7 million for one year’s 

worth of commercial building construction. 

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Nebraska 

13 Nebraska 

Nebraska has adopted ASHRAE 90.1-2007 as its state energy code for commercial 

buildings, and is located in the West North Central Census Division and Climate 

Zone 5A. Table 13-1 provides an overview of Nebraska’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 

87 kWh/m2 to 107 kWh/m2 (28 kBtu/ft2 to 34 kBtu/ft2

) annually. The high school uses 

the greatest amount of energy at 238 kWh/m2 to 252 kWh/m2 (75 kBtu/ft2 to 80 kBtu/ft2) 

annually. 

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

Nebraska 

Building 

Type 

Standard Edition 

2007 

kWh/m2 kBtu/ft2 

LEC 

kWh/m2 kBtu/ft2 

APART04 

APART06 

167 53 

166 53 

151 48 

147 47 

DORMI04 

DORMI06 

131 41 

184 58 

115 37 

164 52 

HOTEL15 176 56 153 49 

HIGHS02 252 80 238 75 

OFFIC03 

OFFIC08 

OFFIC16 

117 37 

107 34 

168 53 

96 30 

87 28 

142 45 

RETAIL1 132 42 116 37 

RSTRNT1 183 58 139 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. 

13.1 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 Nebraska. 

13.1.1 Statewide Building Comparison 

Table 13-2 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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Nebraska 

There is significant variation in the change in energy use for the LEC design relative to 

ASHRAE 90.1-2007, ranging from -5.8 % to -24.2 % depending on the building type with 

an overall average of -13.7 %. High schools realize the lowest reduction in energy use 

while restaurants realize the greatest reduction in energy use. 

Table 13-2 Average Percentage Change from Adoption of the LEC Design, 10-Year, 

Nebraska 

Building LEC 

Type Energy Use Energy Cost Carbon LCC 

APART04 -9.8 -16.3 -17.2 0.7 

APART06 -11.2 -19.5 -20.5 0.6 

DORMI04 -11.7 -17.2 -17.9 -0.2 

DORMI06 -10.9 -18.8 -19.8 0.3 

HOTEL15 -12.7 -18.9 -19.7 0.6 

HIGHS02 -5.8 -15.0 -16.4 -0.6 

OFFIC03 -18.2 -23.0 -23.5 -2.3 

OFFIC08 -18.5 -21.2 -21.5 -2.2 

OFFIC16 -15.2 -20.2 -20.7 0.8 

RETAIL1 -12.5 -16.8 -17.2 0.8 

RSTRNT1 -24.2 -32.6 -33.5 -3.9 

Average -13.7 -19.9 -20.7 -0.5 

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 -15.0 % to -32.6 % depending 

on the building type with an average of -19.9 % 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. For 9 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 

42.2 % of the reduction in electricity consumption, and results in a percentage reduction 

in energy costs that is nearly three times greater than the percentage reduction in energy 

use. The LEC design incorporates daylighting and overhangs into the building design 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 -16.4 % to -33.5 % with an average of -20.7 %. 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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Nebraska 

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 9 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 -3.9 % to 0.8 % 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 -0.5 % 

in life-cycle costs, the LEC design may be cost-effective if the state adopted it as its state 

energy code for commercial buildings. 

13.1.2 City Comparisons 

Simulations are run for five cities located in Nebraska, all of which are located in
 

Zone 5A: Grand Island, Norfolk, North Platte, Omaha, and Scottsbluff. While the five
 

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 13-3 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 -13.1 %
 

to -14.1 %. Any variation in local climate appears to have minimal effects on energy
 

consumption.
 

Table 13-3 Average Percentage Change from Adoption of the LEC Design by City, 

10-Year, Nebraska 

Cities Zone LEC 

Energy Use Energy Cost Carbon LCC 

Grand Island 5A -13.8 -19.9 -20.9 -0.5 

Norfolk 5A -13.1 -19.4 -20.3 -0.3 

North Platte 5A -13.5 -20.1 -21.1 -0.5 

Omaha 5A -14.0 -19.8 -20.7 -0.5 

Scottsbluff 5A -14.1 -20.6 -21.6 -0.6 

Average -13.7 -19.9 -20.9 -0.5 

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Nebraska 

The average percentage change in energy costs for all building types also varies 

minimally across cities, ranging from -19.4 % to -20.6 % for 10 years of operation. For 

all cities, reductions in energy costs are greater than reductions in energy use because of 

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, ranging from -20.3 % 

to -21.6 %. Percentage changes in life-cycle costs for all building types vary minimally 

across cities, ranging from -0.3 % to -0.6 %. 

13.2 Total Savings 

How much can Nebraska 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. 

13.2.1 Energy Use 

Table 13-4 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 13-5 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 

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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Nebraska 

Table 13-4 Average Per Unit Change in Annual Energy Use, Nebraska
 

Building Standard Edition 

Type LEC 

kWh/m2 kBtu/ft2 

APART04 -16.3 -5.2 

APART06 -18.5 -5.9 

DORMI04 -15.3 -4.8 

DORMI06 -20.0 -6.4 

HOTEL15 -22.3 -7.1 

HIGHS02 -21.4 -6.8 

OFFIC03 -14.7 -4.7 

OFFIC08 -19.7 -6.2 

OFFIC16 -25.4 -8.1 

RETAIL1 -16.5 -5.2 

RSTRNT1 -44.3 -14.1 

The adoption of the LEC design as the state’s energy code for commercial buildings 

would save energy for all building types and 10.4 GWh (35.4 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 60.8 % 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 statewide savings to 

be 17.1 GWh (58.3 GBtu) per year. These savings imply 170.8 GWh (583.0 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 41.1 % and 18.4 %, 

respectively, of the new construction in the state while all other building types represent 

10.8 % 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 

13-2. 

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Nebraska 

Table 13-5 Statewide Change in Annual Energy Use for One Year of Construction, 

Nebraska 

Building Subcategory m 2 ft2 Standard Edition 

Type Weighting (1000s) (1000s) LEC 

kWh kBtu 

APART04 44.9 % 13.2 143 -216 456 -739 075 

APART06 55.1 % 16.2 175 -299 533 -1 022 735 

HOTEL15 100.0 % 60.6 653 -1 353 727 -4 622 206 

HIGHS02 100.0 % 102.8 1107 -1 508 953 -5 152 215 

OFFIC03 37.4 % 47.2 508 -1 009 922 -3 448 308 

OFFIC08 40.4 % 50.9 548 -1 001 908 -3 420 946 

OFFIC16 22.2 % 28.0 302 -712 920 -2 434 216 

RETAIL1 100.0 % 229.8 2474 -3 803 322 -12 986 176 

RSTRNT1 100.0 % 10.7 115 -475 386 -1 623 171 

Total 559.6 6024 -10 382 128 -35 449 048 

Note: Dormitories are excluded because no such floor area category is reported 

in the construction data. 

13.2.2 Energy Costs 

Table 13-6 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 13-6 Average Per Unit Change in Energy Costs, 10-Year, Nebraska 

Building Standard Edition 

Type LEC 

$/m2 $/ft2 

APART04 -$10.38 -$0.96 

APART06 -$12.44 -$1.16 

DORMI04 -$8.79 -$0.82 

DORMI06 -$13.26 -$1.23 

HOTEL15 -$12.92 -$1.20 

HIGHS02 -$13.37 -$1.24 

OFFIC03 -$13.07 -$1.21 

OFFIC08 -$12.04 -$1.12 

OFFIC16 -$15.86 -$1.47 

RETAIL1 -$9.94 -$0.92 

RSTRNT1 -$26.59 -$2.47 

Table 13-7 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 $6.7 million for 10 years of building operation. 

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Nebraska 

Assuming that the buildings considered in this study, which represent 60.8 % 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 the LEC design can be extrapolated 

to estimate the total statewide energy cost savings of $11.1 million over the 10-year study 

period. 

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

10-Year, Nebraska 

Building Subcategory m 2 ft2 Standard Edition
 

Type Weighting (1000s) (1000s) LEC
 

APART04 44.9 % 13.2 143 -$137 494 

APART06 55.1 % 16.2 175 -$201 839 

HOTEL15 100.0 % 60.6 653 -$783 535 

HIGHS02 100.0 % 102.8 1107 -$1 343 471 

OFFIC03 37.4 % 47.2 508 -$631 499
 

OFFIC08 40.4 % 50.9 548 -$612 857
 

OFFIC16 22.2 % 28.0 302 -$444 397 

RETAIL1 100.0 % 229.8 2474 -$2 284 163 

RSTRNT1 100.0 % 10.7 115 -$285 042 

Total 559.6 6024 -$6 724 297 

Note: Dormitories are excluded because no such floor area category 

is reported in the construction data. 

13.2.3 Energy-related Carbon Emissions 

Table 13-8 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 13-8 Average Per Unit Change in Carbon Emissions, 10-Year, Nebraska 

Building Standard Edition 

Type LEC 

kg/m2 lb/ft2 

APART04 -156.1 -32.0 

APART06 -188.0 -38.5 

DORMI04 -131.2 -26.9 

DORMI06 -200.1 -41.0 

HOTEL15 -193.0 -39.5 

HIGHS02 -200.8 -41.1 

OFFIC03 -200.9 -41.2 

OFFIC08 -180.5 -37.0 

OFFIC16 -238.2 -48.8 

RETAIL1 -148.9 -30.5 

RSTRNT1 -398.1 -81.5 

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Nebraska 

Table 13-9 applies the Table 13-8 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 101 296 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 166 606 metric tons over the 

10-year study period. 

Table 13-9 Statewide Change in Total Carbon Emissions for One Year of 

Construction, 10-Year, Nebraska – Metric Tons 

Building Subcategory m 2 ft2 Standard Edition
 

Type Weighting (1000s) (1000s)
 LEC 

APART04 44.9 % 13.2 143 -2068 

APART06 55.1 % 16.2 175 -3049 

HOTEL15 100.0 % 60.6 653 -11 700 

HIGHS02 100.0 % 102.8 1107 -20 646 

OFFIC03 37.4 % 47.2 508 -9488 

OFFIC08 40.4 % 50.9 548 -9192 

OFFIC16 22.2 % 28.0 302 -6675 

RETAIL1 100.0 % 229.8 2474 -34 210 

RSTRNT1 100.0 % 10.7 115 -4268 

Total 559.6 6024 -101 296 

Note: Dormitories are excluded because no such floor area category is 

reported in the construction data. 

13.2.4 Life-Cycle Costs 

Table 13-10 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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Nebraska 

Table 13-10 Average Per Unit Change in Life-Cycle Costs, 10-Year, Nebraska
 

Building Standard Edition 

Type LEC 

$/m2 $/ft2 

APART04 $6.51 $0.61 

APART06 $5.43 $0.50 

DORMI04 -$1.75 -$0.16 

DORMI06 $2.69 $0.25 

HOTEL15 $5.51 $0.51 

HIGHS02 -$4.79 -$0.45 

OFFIC03 -$17.09 -$1.59 

OFFIC08 -$16.88 -$1.57 

OFFIC16 $5.62 $0.52 

RETAIL1 $5.03 $0.47 

RSTRNT1 -$48.43 -$4.50 

Table 13-11 applies the Table 13-10 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 $857 290 in statewide life-cycle costs 

relative to ASHRAE 90.1-2007. Eight-story office buildings ($859 676) and 3-story 

office buildings ($806 793) realize the greatest reductions in life-cycle costs. Retail stores 

realize the greatest increase in life-cycle costs ($1.2 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 $1.4 million over the 10-year study period. 

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Nebraska 

Table 13-11 Statewide Change in Life-Cycle Costs for One Year of Construction, 

10-Year, Nebraska 

Building Subcategory m 2 ft2 Standard Edition
 

Type Weighting (1000s) (1000s) LEC
 

APART04 44.9 % 13.2 143 $86 268 

APART06 55.1 % 16.2 175 $88 078 

HOTEL15 100.0 % 60.6 653 $334 231 

HIGHS02 100.0 % 102.8 1107 -$492 735 

OFFIC03 37.4 % 47.2 508 -$806 793 

OFFIC08 40.4 % 50.9 548 -$859 676 

OFFIC16 22.2 % 28.0 302 $157 380 

RETAIL1 100.0 % 229.8 2474 $1 155 175 

RSTRNT1 100.0 % 10.7 115 -$519 218 

Total 559.6 6024 -$857 290 

Note: Dormitories are excluded because no such floor area category 

is reported in the construction data. 

13.3 State Summary 

Nebraska 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 170.8 GWh (583.0 GBtu), 

energy cost savings of $11.1 million, and carbon emissions reductions of 166 606 metric 

tons while decreasing life-cycle costs of $1.4 million for one year’s worth of commercial 

building construction. 

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North Dakota 

14 North Dakota 

North Dakota is located in the West North Central Census Division and spans two 

climate zones (Zone 6 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 14-1 provides an overview of 

North Dakota’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 96 kWh/m2 to 129 kWh/m2 

(30 kBtu/ft2 to 41 kBtu/ft2) annually. The high school uses the greatest amount of energy 

at 308 kWh/m2 to 346 kWh/m2 (104 kBtu/ft2 to 110 kBtu/ft2) annually. 

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

North Dakota 

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 

219 69 

216 68 

218 69 

215 68 

211 67 

207 66 

200 63 

197 63 

180 57 

179 57 

DORMI04 

DORMI06 

177 56 

238 75 

175 55 

237 75 

173 55 

228 72 

160 51 

216 69 

138 44 

198 63 

HOTEL15 211 67 209 66 207 66 210 67 190 60 

HIGHS02 346 110 345 109 343 109 329 104 308 98 

OFFIC03 

OFFIC08 

OFFIC16 

147 47 

129 41 

187 59 

146 46 

127 40 

186 59 

143 45 

122 39 

188 60 

129 41 

115 37 

191 61 

104 33 

96 30 

168 53 

RETAIL1 184 58 183 58 176 56 155 49 125 40 

RSTRNT1 255 81 252 80 248 79 203 64 149 47 

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. 

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 more energy efficient designs for the state of North Dakota. 

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14.1.1 Energy Use 

Table 14-2 shows minimal change in energy use from adopting ASHRAE 90.1-2001 

relative to ASHRAE 90.1-1999 with all 11 building types realizing reductions in energy 

use of 1.7 % or less. There is a small decrease in energy use for 10 of 11 building types 

for ASHRAE 90.1-2004, with the percentage change in energy use ranging from 0.4 % 

to -5.7 % with an average of -2.9 %. The average change in energy use from constructing 

buildings using ASHRAE 90.1-2007 requirements ranges from 2.2 % to -20.6 %, with an 

overall average of -8.9 %. 

Table 14-2 Average Percentage Change in Energy Use from Adoption of Newer 

Standard Editions, North Dakota 

Building Standard Edition 

Type 2001 2004 2007 LEC 

APART04 -0.3 -3.7 -8.5 -17.5 

APART06 -0.4 -4.1 -8.5 -17.2 

DORMI04 -1.0 -1.7 -9.3 -21.6 

DORMI06 -0.4 -4.2 -9.0 -16.6 

HOTEL15 -0.6 -1.7 -0.4 -10.0 

HIGHS02 -0.4 -1.0 -4.9 -11.1 

OFFIC03 -1.2 -3.1 -12.5 -29.5 

OFFIC08 -1.7 -5.7 -10.7 -26.0 

OFFIC16 -0.7 0.4 2.2 -9.9 

RETAIL1 -0.7 -4.1 -15.7 -31.8 

RSTRNT1 -1.3 -2.8 -20.6 -41.8 

Average -0.8 -2.9 -8.9 -21.2 

The ASHRAE 90.1-2004 and ASHRAE 90.1-2007 designs realize an increase for the 

16-story office building. 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 North Dakota, 

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 6 and Zone 7 is increased from ASHRAE 

90.1-2004 to ASHRAE 90.1-2007, making the requirement less strict. 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 -9.9 % to -41.8 % with an average 

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North Dakota 

of -21.2 %. 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 ratio due to 

the less strict window SHGC requirement. 

14.1.2 Energy Costs 

Table 14-3 shows minimal 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 -5.1 % to -15.9 % depending on the building type, 

with an average of -11.7 %. The average change in energy costs from constructing 

buildings using ASHRAE 90.1-2007 requirements ranges from -1.8 % to -20.8 %, with an 

overall average of -14.6 %. The LEC design realizes the greatest change in energy costs, 

with the average change by building type ranging from -13.5 % to -44.2 % with an 

average of -28.5 % overall. 

Table 14-3 Average Percentage Change in Energy Costs, 10-Year, North Dakota 

Building Standard Edition 

Type 2001 2004 2007 LEC 

APART04 -0.5 -15.6 -18.8 -30.8 

APART06 -0.6 -15.9 -18.8 -30.5 

DORMI04 -1.4 -15.8 -20.2 -33.7 

DORMI06 -0.6 -15.3 -18.3 -28.8 

HOTEL15 -0.9 -14.0 -10.9 -20.8 

HIGHS02 -0.7 -5.1 -8.1 -18.9 

OFFIC03 -1.6 -8.5 -12.9 -30.5 

OFFIC08 -2.0 -10.4 -12.5 -28.1 

OFFIC16 -1.0 -5.5 -1.8 -13.5 

RETAIL1 -1.0 -11.5 -18.0 -33.4 

RSTRNT1 -1.8 -10.7 -20.8 -44.2 

Average -1.1 -11.7 -14.6 -28.5 

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 reduced 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. Even the 16-story office building, which realizes a percentage increase in 

energy use, realizes a percentage reduction in energy costs due to a shift in energy use 

from electricity to natural gas. 

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North Dakota 

14.1.3 Energy-related Carbon Emissions 

Minimal change in energy use leads to small changes (2.0 % or less) in cradle-to-grave 

energy-related carbon emissions for the ASHRAE 90.1-2001 design across all building 

types. Table 14-4 shows a significant change in average energy-related carbon emissions 

for ASHRAE 90.1-2004 for all building types, ranging from -6.1 % to -18.5 % with an 

average of -13.3 %. 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 -2.4 % to -20.9 % and an overall average of -15.7 %. The LEC design leads to the 

greatest average carbon emissions changes, ranging from -14.1 % to -44.6 % depending 

on the building type with an average of -29.9 % across all building types. 

Table 14-4 Average Percentage Change in Energy-related Carbon Emissions, 10­

Year, North Dakota 

Building Standard Edition 

Type 2001 2004 2007 LEC 

APART04 -0.6 -18.0 -20.9 -33.4 

APART06 -0.6 -18.2 -20.8 -33.1 

DORMI04 -1.5 -18.5 -22.2 -36.0 

DORMI06 -0.6 -17.4 -20.2 -31.2 

HOTEL15 -1.0 -16.3 -12.9 -22.8 

HIGHS02 -0.7 -6.1 -8.9 -20.8 

OFFIC03 -1.6 -9.3 -13.0 -30.6 

OFFIC08 -2.0 -11.1 -12.8 -28.4 

OFFIC16 -1.0 -6.5 -2.4 -14.1 

RETAIL1 -1.0 -12.8 -18.4 -33.7 

RSTRNT1 -1.9 -12.1 -20.9 -44.6 

Average -1.2 -13.3 -15.7 -29.9 

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 further decreases carbon 

emissions because electricity has a higher carbon emissions rate per unit of energy than 

natural gas in North Dakota. The 16-story office building realizes reductions in carbon 

emissions from adopting the ASHRAE 90.1-2004 and -2007 designs even though it 

realizes a percentage increase in energy use due to a shift in energy use from electricity to 

natural gas. 

14.1.4 Life-Cycle Costs 

The most cost-effective building design for each building type is bolded in Table 14-5. 

Life-cycle costs increase for the ASHRAE 90.1-2001 design compared to ASHRAE 

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North Dakota 

90.1-1999 for 8 of 11 building types over a 10-year study period. ASHRAE 90.1-1999 is 

the lowest cost building design for three building types while ASHRAE 90.1-2004, 

ASHRAE 90.1-2007, and the LEC design are the lowest cost building design for one, five, 

and two building types, respectively. The change in life-cycle costs for ASHRAE 

90.1-2004 and -2007 ranges from -2.1 % to 5.8 % depending on building type. The LEC 

design realizes a reduction in life-cycle costs for 6 of 11 building types, with the 

percentage change in life-cycle costs ranging from -1.6 % to 1.3 %. Based on the overall 

average percentage reduction in life-cycle costs of 0.2 %, the LEC design may be costeffective if the state adopted it as its state energy code for commercial buildings. 

Table 14-5 Average Percentage Change in Life-Cycle Costs, 10-Year, North Dakota 

Building Standard Edition 

Type 2001 2004 2007 LEC 

APART04 0.1 -1.1 -1.6 -1.0 

APART06 0.0 -1.2 -1.6 -0.9 

DORMI04 3.3 1.6 1.2 0.3 

DORMI06 -0.0 -1.7 -2.1 -1.6 

HOTEL15 -0.0 -1.8 -1.6 -1.1 

HIGHS02 0.7 0.1 -0.4 -0.9 

OFFIC03 5.0 3.1 2.4 0.8 

OFFIC08 4.9 2.9 2.5 1.3 

OFFIC16 -0.0 -0.5 -0.2 0.4 

RETAIL1 2.8 0.5 -0.3 0.6 

RSTRNT1 6.7 5.8 2.9 -0.2 

Average 2.1 0.7 0.1 -0.2 

14.1.5 City Comparisons 

Simulations are run for three cities located in North Dakota: Bismarck in Climate 

Zone 6A, and Fargo and Minot in Climate Zone 7. The results may vary across cities 

within North Dakota for three 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 14-6, the average reduction in energy use for all building types 

from adopting newer energy standard editions varies by standard edition and city. For 

ASHRAE 90.1-2004 and -2007, the city located in the warmer climate zone (Zone 6A) 

realizes greater reductions in energy use than the cities in the colder climate zone (Zone 

7). Meanwhile, the percentage reduction in energy use varies minimally for the ASHRAE 

90.1-2001 and LEC design. 

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North Dakota 

Table 14-6 Average Percentage Change in Energy Use from Adoption of Newer 

Standard Editions by City, North Dakota 

Cities Zone Standard Edition 

2001 2004 2007 LEC 

Bismarck 6A -0.8 -5.8 -10.0 -21.0 

Fargo 7 -0.8 -1.5 -8.3 -21.1 

Minot 7 -0.8 -1.4 -8.4 -21.4 

Average -0.8 -2.9 -8.9 -21.2 

The variations in the percentage change in energy costs across cities are a result of two 

factors, the reduction in energy use and the fuel source of the reduction. Table 14-7 

shows that the average reduction in energy costs for all building types is greater for the 

city in Zone 6A relative to cities in Zone 7 for the ASHRAE 90.1-2004 and -2007 designs. 

For the LEC design, there is minimal variation in the percentage change in energy costs 

across cities in different climate zones. 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. 

Table 14-7 Average Percentage Change in Energy Costs by City, 10-Year, North 

Dakota 

Cities Zone Standard Edition 

2001 2004 2007 LEC 

Bismarck 6A -1.1 -13.6 -15.5 -28.9 

Fargo 7 -1.2 -10.6 -14.2 -28.0 

Minot 7 -1.1 -10.7 -14.3 -28.4 

Average -1.1 -11.7 -14.6 -28.5 

Table 14-8 reports changes in energy-related carbon emissions by city for North Dakota. 

For all cities, the more stringent standard editions result in greater reductions in carbon 

emissions. As with the energy use, the city in Zone 6A realizes a greater average change 

in emissions than the cities in Zone 7 for the ASHRAE 90.1-2004 and ASHRAE 90.1-2007 

design while there is minimal difference for the ASHRAE 90.1-2001 and LEC designs. 

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North Dakota 

Table 14-8 Average Percentage Change in Carbon Emissions by City, 10-Year, 

North Dakota 

Cities Zone Standard Edition 

2001 2004 2007 LEC 

Bismarck 6A -1.0 -14.5 -16.2 -30.4 

Fargo 7 -1.1 -11.7 -15.0 -29.3 

Minot 7 -1.0 -11.8 -15.1 -29.7 

Average -1.1 -12.7 -15.4 -29.8 

The data reported in Table 14-9 show that, over a 10-year period, average life-cycle costs 

increase for all cities for ASHRAE 90.1-2001 and -2004 compared to ASHRAE 90.1-1999. 

For the ASHRAE 90.1-2007 design, the city in Zone 6A (Bismarck) realizes a percentage 

reduction in life-cycle costs while the cities in Zone 7 realize a percentage increase in 

life-cycle costs. For the LEC design, Bismarck and Minot realize percentage reductions 

in life-cycle costs while Fargo realizes a slight percentage increase in life-cycle costs. 

Table 14-9 Average Percentage Change in Life-Cycle Costs by City, 10-Year, North 

Dakota 

Cities Zone Standard Edition 

2001 2004 2007 LEC 

Bismarck 6A 2.1 0.3 -0.1 -0.5 

Fargo 7 2.2 0.9 0.3 0.0
 

Minot 7 2.1 0.9 0.2 -0.2
 

Average 2.1 0.7 0.1 -0.2 

14.2 Total Savings 

How much can North Dakota 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 14-10 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 14-11 reports the 

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. 

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North Dakota 

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.31 

Table 14-10 Average Per Unit Change in Annual Energy Use, North Dakota 

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 

-0.8 -0.2 

-0.8 -0.3 

-8.0 -2.5 

-8.8 -2.8 

-18.7 -5.9 

-18.3 -5.8 

-38.2 -12.1 

-37.0 -11.7 

DORMI04 

DORMI06 

-1.7 -0.5 

-0.9 -0.3 

-3.1 -1.0 

-10.0 -3.2 

-16.5 -5.2 

-21.4 -6.8 

-38.1 -12.1 

-39.5 -12.5 

HOTEL15 -1.3 -0.4 -3.6 -1.2 -0.9 -0.3 -21.1 -6.7 

HIGHS02 -1.2 -0.4 -4.6 -1.5 -18.5 -5.9 -43.5 -13.8 

OFFIC03 

OFFIC08 

OFFIC16 

-1.8 -0.6 

-2.2 -0.7 

-1.4 -0.4 

-3.6 -1.1 

-7.4 -2.4 

0.6 0.2 

-17.0 -5.4 

-13.9 -4.4 

4.0 1.3 

-38.6 -12.3 

-33.5 -10.6 

-18.6 -5.9 

RETAIL1 -1.3 -0.4 -7.6 -2.4 -28.8 -9.1 -58.6 -18.6 

RSTRNT1 -3.2 -1.0 -7.1 -2.3 -52.5 -16.6 -106.7 -33.8 

The total annual reduction in energy use ranges widely across building designs, but the 

ASHRAE 90.1-2001, -2004, and -2007, and LEC designs all decrease overall energy use 

across the state. Adopting the ASHRAE 90.1-2001, -2004, and -2007 designs result in an 

annual decrease of 213 MWh (726 MBtu), 853 MWh (2.9 GBtu), and 3.0 GWh 

(10.3 GBtu) annually, respectively. 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 for one year’s worth of new construction for these building types. The 

ASHRAE 90.1-2004 and -2007 designs increase total energy use for the 16-story office 

building relative to ASHRAE 90.1-1999 because of the changes in building envelope 

requirements as a result of the consolidation of climate zones. 

31 State-level subcategory data are not available. 

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North Dakota 

Table 14-11 Statewide Change in Annual Energy Use for One Year of Construction, 

North Dakota 

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 % 

0.7 

0.7 

7 

8 

-0 -2 

-1 -2 

-5 -17 

-7 -23 

-12 -40 

-14 -49 

-24 -83 

-29 -98 

HOTEL15 100.0 % 18.2 196 -24 -82 -66 -227 -16 -55 -385 -1315 

HIGHS02 100.0 % 34.7 374 -43 -148 -125 -426 -591 -2019 -1343 -4587 

OFFIC03 

OFFIC08 

OFFIC16 

37.4 % 

40.4 % 

22.2 % 

10.4 

11.1 

6.1 

112 

120 

66 

-19 -64 

-24 -83 

-9 -29 

-47 -162 

-83 -283 

4 13 

-192 -655 

-155 -529 

25 84 

-451 -1538 

-374 -1279 

-114 -390 

RETAIL1 100.0 % 66.2 713 -83 -284 -503 -1718 -1911 -6526 -3881 -13 251 

RSTRNT1 100.0 % 2.9 31 -9 -32 -21 -70 -151 -516 -307 -1049 

Total 151.2 1628 -213 -726 -853 -2914 -3018 -10 305 -6909 -23 590 

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 66.1 % 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 10.5 

GWh (35.7 GBtu) per year. These savings imply 104.5 GWh (356.9 GBtu) in energy use 

savings over the 10-year study period. In comparison, ASHRAE 90.1-2007 would save 

4.6 GWh (15.6 GBtu) annually or 45.7 GWh (155.9 GBtu) over the 10-year study period. 

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 greatest total reductions are realized by retail stores 

and high schools because they represent 43.8 % and 22.9 %, respectively, of the new 

construction in the state while all other building types represent 12.0 % or less. The 

amount of new construction overwhelms the relative percentage 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. 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 14-2. 

14.2.2 Energy Costs 

Table 14-12 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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North Dakota 

Table 14-12 Average Per Unit Change in Energy Costs, 10-Year, North Dakota
 

Building Standard Edition 

Type 2001 

$/m2 $/ft2 

2004 

$/m2 $/ft2 

2007 

$/m2 $/ft2 

LEC 

$/m2 $/ft2 

APART04 

APART06 

-$0.42 

-$0.44 

-$0.04 

-$0.04 

-$12.24 

-$12.44 

-$1.14 

-$1.16 

-$14.76 

-$14.69 

-$1.37 

-$1.36 

-$24.10 

-$23.88 

-$2.24 

-$2.22 

DORMI04 

DORMI06 

-$0.95 

-$0.50 

-$0.09 

-$0.05 

-$10.39 

-$13.06 

-$0.97 

-$1.21 

-$13.23 

-$15.70 

-$1.23 

-$1.46 

-$22.10 

-$24.63 

-$2.05 

-$2.29 

HOTEL15 -$0.73 -$0.07 -$10.95 -$1.02 -$8.56 -$0.80 -$16.31 -$1.52 

HIGHS02 -$1.00 -$0.09 -$5.36 -$0.50 -$8.18 -$0.76 -$19.31 -$1.79 

OFFIC03 

OFFIC08 

OFFIC16 

-$0.69 

-$1.21 

-$0.77 

-$0.06 

-$0.11 

-$0.07 

-$5.33 

-$6.31 

-$4.32 

-$0.50 

-$0.59 

-$0.40 

-$8.49 

-$7.59 

-$1.41 

-$0.79 

-$0.70 

-$0.13 

-$19.85 

-$17.03 

-$10.61 

-$1.84 

-$1.58 

-$0.99 

RETAIL1 -$0.70 -$0.06 -$8.23 -$0.77 -$12.86 -$1.19 -$23.89 -$2.22 

RSTRNT1 -$1.78 -$0.17 -$10.48 -$0.97 -$20.48 -$1.90 -$43.40 -$4.03 

Table 14-13 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 ($117 799). ASHRAE 90.1-2004, ASHRAE 90.1-2007, and the LEC 

design realize reductions in energy costs of $1.1 million, $1.6 million, and $3.2 million 

respectively. The 16-story office buildings that realize an increase in total energy use 

from the adoption of the ASHRAE 90.1-2004 and ASHRAE 90.1-2007 designs realize a 

decrease in total energy costs because of the shift in energy consumption from electricity 

to natural gas. 

Assuming that the buildings considered in this study, which represent 66.1 % 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 $178 214, $1.7 million, $2.4 million, and 

$4.8 million over the 10-year study period, respectively. 

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North Dakota 

Table 14-13 Statewide Change in Energy Costs for One Year of Construction, 

10-Year, North Dakota 

Building Subcategory m 2 ft2 Standard Edition 

Type Weighting (1000s) (1000s) 2001 2004 2007 LEC 

APART04 44.9 % 0.7 7 -$268 -$7771 -$9366 -$15 298 

APART06 55.1 % 0.7 8 -$342 -$9673 -$11 417 -$18 565 

HOTEL15 100 % 18.2 196 -$13 380 -$199 866 -$156 225 -$297 550 

HIGHS02 100 % 34.7 374 -$24 005 -$185 385 -$295 274 -$689 980 

OFFIC03 37.4 % 10.4 112 -$10 321 -$55 528 -$84 737 -$200 121 

OFFIC08 40.4 % 11.1 120 -$13 499 -$70 561 -$84 797 -$190 346 

OFFIC16 22.2 % 6.1 66 -$4743 -$26 537 -$8678 -$65 222 

RETAIL1 100 % 66.2 713 -$46 114 -$545 753 -$852 105 -$1 583 528 

RSTRNT1 100 % 2.9 31 -$5129 -$30 184 -$58 983 -$125 002 

Total 151.2 1628 -$117 799 -$1 131 258 -$1 561 583 -$3 185 613 

Note: Dormitories are excluded because no such floor area category is reported in the construction data. 

14.2.3 Energy-related Carbon Emissions 

Table 14-14 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 14-14 Average Per Unit Change in Carbon Emissions, 10-Year, North Dakota 

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 

-6.8 -1.4 

-7.1 -1.5 

-212.3 -43.5 

-215.0 -44.0 

-246.3 -50.4 

-245.3 -50.2 

-394.0 -80.7 

-391.2 -80.1 

DORMI04 

DORMI06 

-15.2 -3.1 

-8.0 -1.6 

-184.1 -37.7 

-224.8 -46.1 

-221.0 -45.3 

-260.3 -53.3 

-358.0 -73.3 

-402.2 -82.4 

HOTEL15 -11.8 -2.4 -193.7 -39.7 -153.5 -31.4 -271.6 -55.6 

HIGHS02 -11.1 -2.3 -92.3 -18.9 -135.1 -27.7 -316.8 -64.9 

OFFIC03 

OFFIC08 

OFFIC16 

-16.0 -3.3 

-19.5 -4.0 

-12.4 -2.5 

-91.8 -18.8 

-106.0 -21.7 

-78.5 -16.1 

-127.8 -26.2 

-122.1 -25.0 

-29.7 -6.1 

-302.0 -61.8 

-271.5 -55.6 

-171.5 -35.1 

RETAIL1 -11.2 -2.3 -140.4 -28.8 -201.1 -41.2 -368.5 -75.5 

RSTRNT1 -28.7 -5.9 -181.4 -37.2 -313.4 -64.2 -669.1 -137.0 

Table 14-15 applies the Table 14-14 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 90.1-2001, 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 19 494 metric tons 

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North Dakota 

and 24 947 metric tons over a 10-year study period, respectively. The 16-story office 

buildings, which realize 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 electricity consumption. The adoption of LEC as the state’s 

energy code decreases carbon emissions by 50 089 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 90.1-2001, 

ASHRAE 90.1-2004, ASHRAE 90.1-2007, and LEC can be extrapolated to estimate 

statewide reductions in carbon emissions of 2871 metric tons, 29 491 metric tons, 

37 741 metric tons, and 75 777 metric tons over the 10-year study period, respectively. 

Table 14-15 Statewide Change in Total Carbon Emissions for One Year of 

Construction, 10-Year, North Dakota – Metric Tons 

Building Subcategory m 2 ft2 Standard Edition 

Type Weighting (1000s) (1000s) 2001 2004 2007 LEC 

APART04 44.9 % 0.7 7 -4 -135 -156 -250 

APART06 55.1 % 0.7 8 -6 -167 -191 -304 

HOTEL15 100.0 % 18.2 196 -216 -3534 -2801 -4956 

HIGHS02 100.0 % 34.7 374 -387 -3210 -4695 -11 012 

OFFIC03 37.4 % 10.4 112 -166 -951 -1324 -3129 

OFFIC08 40.4 % 11.1 120 -217 -1184 -1364 -3034 

OFFIC16 22.2 % 6.1 66 -76 -483 -183 -1054 

RETAIL1 100.0 % 66.2 713 -743 -9307 -13 331 -24 422 

RSTRNT1 100.0 % 2.9 31 -83 -523 -903 -1927 

Total 151.2 1628 -1898 -19 494 -24 947 -50 089 

Note: Dormitories are excluded because no such floor area category is reported in the 

construction data. 

14.2.4 Life-Cycle Costs 

Table 14-16 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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North Dakota 

Table 14-16 Average Per Unit Change in Life-Cycle Costs, 10-Year, North Dakota
 

Building Standard Edition 

Type 2001 

$/m2 $/ft2 

2004 

$/m2 $/ft2 

2007 

$/m2 $/ft2 

LEC 

$/m2 $/ft2 

APART04 $0.62 $0.06 -$10.13 -$0.94 -$14.89 -$1.38 -$8.74 -$0.81 

APART06 $0.13 $0.01 -$10.87 -$1.01 -$14.62 -$1.36 -$7.78 -$0.72 

DORMI04 $27.83 $2.59 $13.76 $1.28 $10.24 $0.95 $2.32 $0.22 

DORMI06 -$0.16 -$0.01 -$15.95 -$1.48 -$19.59 -$1.82 -$15.15 -$1.41 

HOTEL15 -$0.45 -$0.04 -$16.42 -$1.53 -$14.09 -$1.31 -$9.57 -$0.89 

HIGHS02 $5.33 $0.50 $0.72 $0.07 -$2.75 -$0.26 -$6.87 -$0.64 

OFFIC03 $34.76 $3.23 $21.55 $2.00 $16.84 $1.56 $5.29 $0.49 

OFFIC08 $35.26 $3.28 $20.69 $1.92 $17.75 $1.65 $9.45 $0.88 

OFFIC16 -$0.11 -$0.01 -$3.74 -$0.35 -$1.27 -$0.12 $2.82 $0.26 

RETAIL1 $16.16 $1.50 $3.03 $0.28 -$1.49 -$0.14 $3.66 $0.34 

RSTRNT1 $75.17 $6.98 $65.25 $6.06 $33.06 $3.07 -$2.54 -$0.24 

Table 14-17 applies the Table 14-16 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 

the ASHRAE 90.1-2001 design results in an increase in life-cycle costs for 7 of 9 building 

types. The ASHRAE 90.1-2004 and -2007 designs result in a decrease in life-cycle costs 

for 4 and 6 building types with total life-cycle costs increasing by $531 099 and 

decreasing by $12 000, respectively. Adopting the LEC design decreases life-cycle costs 

for 5 of 9 building types, and decreases total life-cycle costs by $11 945. For a 10-year 

study period, it is cost-effective to adopt the ASHRAE 90.1-2007 or 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 the ASHRAE 90.1-2001, 

ASHRAE 90.1-2004, ASHRAE 90.1-2007, and LEC designs can be extrapolated to 

estimate statewide changes in life-cycle costs of $3.4 million, $803 478, -$18 154, 

and -$18 072 over the 10-year study period, respectively. 

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North Dakota 

Table 14-17 Statewide Change in Life-Cycle Costs for One Year of Construction, 

10-Year, North Dakota 

Building Subcategory m 2 ft2 Standard Edition 

Type Weighting (1000s) (1000s) 2001 2004 2007 LEC 

APART04 44.9 % 0.7 7 $396 -$6429 -$9452 -$5547 

APART06 55.1 % 0.7 8 $102 -$8452 -$11 364 -$6050 

HOTEL15 100.0 % 18.2 196 -$8138 -$299 673 -$257 043 -$174 538 

HIGHS02 100.0 % 34.7 374 $185 286 $25 185 -$95 654 -$238 926 

OFFIC03 37.4 % 10.4 112 $360 243 $223 264 $174 491 $54 774 

OFFIC08 40.4 % 11.1 120 $393 977 $231 167 $198 301 $105 556 

OFFIC16 22.2 % 6.1 66 -$699 -$22 997 -$7793 $17 315 

RETAIL1 100.0 % 66.2 713 $1 070 934 $201 113 -$98 693 $242 791 

RSTRNT1 100.0 % 2.9 31 $216 479 $187 920 $95 207 -$7320 

Total 151.2 1628 $2 218 579 $531 099 -$12 000 -$11 945 

Note: Dormitories are excluded because no such floor area category is reported in the construction data. 

14.3 State Summary 

North Dakota is one of the states that has no state energy code for commercial buildings, 

and represents the coldest climates in the Midwest Census Region. On average, adopting 

the ASHRAE 90.1-2004, ASHRAE 90.1-2007, or LEC design leads to reductions in 

energy use, energy costs, and cradle-to-grave energy-related carbon emissions. However, 

only the ASHRAE 90.1-2007 and LEC designs do 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 for commercial buildings 

would lead to energy use savings of 45.7 GWh (155.9 GBtu), energy cost savings of 

$2.4 million, and 37 741 metric tons of carbon emissions reductions while saving 

$18 154 in life-cycle costs for one year’s worth of commercial building construction. 

However, adopting the ASHRAE 90.1-2004 and ASHRAE 90.1-2007 designs increase 

energy use for the 16-story office buildings in North Dakota. 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 North Dakota. Additionally, 

ASHRAE 90.1-2007 relaxes the window SHGC requirement above that required in 

ASHRAE 90.1-2004 for North Dakota’s climate zones, leading to lower energy efficiency 

performance. 

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 lead to even greater impacts than adopting ASHRAE 90.1-2007, with 

savings of 104.5 GWh (356.9 GBtu), $4.8 million of energy costs, 75 777 metric tons of 

126
 
 

 

 

 

North Dakota 

carbon emissions, and life-cycle costs of $18 072 for one year’s worth of commercial 

building construction. The LEC design leads to about the same reductions in life-cycle 

costs while realizing much larger reductions in energy use and carbon emissions. 

127
 
North Dakota 

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Ohio 

15 Ohio 

Ohio has adopted ASHRAE 90.1-2007 as its state energy code for commercial buildings, 

is located in the East North Central Census Division, and spans two climate zones (Zone 

4A and Zone 5A). Table 15-1 provides an overview of Ohio’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 

84 kWh/m2 to 102 kWh/m2 (27 kBtu/ft2 to 32 kBtu/ft2

) annually. The high school uses 

the greatest amount of energy at 231 kWh/m2 to 245 kWh/m2 (73 kBtu/ft2 to 78 kBtu/ft2) 

annually. 

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

Ohio 

Building 

Type 

Standard Edition 

2007 

kWh/m2 kBtu/ft2 

LEC 

kWh/m2 kBtu/ft2 

APART04 

APART06 

164 52 

162 52 

148 47 

145 46 

DORMI04 

DORMI06 

128 41 

179 57 

114 36 

160 51 

HOTEL15 171 54 151 48 

HIGHS02 245 78 231 73 

OFFIC03 

OFFIC08 

OFFIC16 

113 36 

102 32 

162 51 

94 30 

84 27 

139 44 

RETAIL1 125 40 109 35 

RSTRNT1 171 54 132 42 

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. 

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 the LEC design in the state of Ohio. 

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. 

129
 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Ohio 

There is significant variation in the change in energy use for the LEC design relative to 

ASHRAE 90.1-2007, ranging from -5.6 % to -23.3 % depending on the building type with 

an overall average of -13.2 %. High schools realize the lowest reduction in energy use 

while restaurants realize the greatest reduction in energy use. 

Table 15-2 Average Percentage Change from Adoption of Newer Standard 

Editions, 10-Year, Ohio 

Building LEC 

Type Energy Use Energy Cost Carbon LCC 

APART04 -9.6 -16.0 -17.1 0.5 

APART06 -10.6 -18.5 -19.9 0.4 

DORMI04 -11.2 -16.9 -17.8 -1.2 

DORMI06 -10.3 -17.9 -19.2 0.1 

HOTEL15 -11.8 -18.1 -19.2 0.4 

HIGHS02 -5.6 -14.2 -15.8 -0.8 

OFFIC03 -17.5 -22.1 -22.7 -2.5 

OFFIC08 -17.9 -20.6 -20.9 -2.2 

OFFIC16 -14.4 -19.5 -20.2 0.5 

RETAIL1 -12.5 -16.1 -16.6 -0.5 

RSTRNT1 -23.3 -31.4 -32.6 -3.4 

Average -13.2 -19.2 -20.2 -0.8 

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 -14.2 % to -31.4 % depending 

on the building type with an average of -19.2 % 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. For 8 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 

42.6 % of the reduction in electricity consumption, and results in a percentage reduction 

in energy costs that is over 2.5 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 change in energy-related carbon emissions 

across building types for the LEC design relative to ASHRAE 90.1-2007, ranging 

from -15.8 % to -32.6 % with an average of -20.2 %. 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 

130
 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Ohio 

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 8 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 -3.4 % to 0.5 % for a 10-year study period. Only 6 of the 11 building types realize 

reductions in life-cycle costs. Based on the overall average percentage change of -0.8 % 

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 six cities located in Ohio, all of which are located in Zone 5A: 

Columbus, Akron, Cleveland, Mansfield, Toledo, and Youngstown. While the six 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 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. The average percentage changes in energy use for all building 

types from adopting the LEC design do not vary significantly across cities, ranging 

from -12.5 % to -14.2 % with an overall average of -13.2 %. 

Table 15-3 Average Percentage Change from Adoption of Newer Standard Editions 

by City, 10-Year, Ohio 

Cities Zone LEC 

Energy Use Energy Cost Carbon LCC 

Columbus 5A -13.2 -19.3 -21.0 -0.8 

Akron 5A -13.4 -19.3 -20.5 -0.7 

Cleveland 5A -14.2 -19.9 -20.5 -0.9 

Mansfield 5A -13.2 -19.2 -20.4 -0.9 

Toledo 5A -12.5 -18.8 -20.0 -0.6 

Youngstown 5A -12.5 -18.7 -20.0 -0.8 

Average -13.2 -19.2 -20.4 -0.8 

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Ohio 

The average percentage change in energy costs for all building types also varies 

minimally across cities, ranging from -18.7 % to -19.9 % 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 minimally across cities, ranging from -20.0 % 

to -21.0 %. Changes in life-cycle costs for all building types vary slightly across cities, 

with the percentage change in life-cycle costs ranging from -0.6 % to -0.9 %. 

15.2 Total Savings 

How much can Ohio 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 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 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.33 

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.
 

132
 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Ohio 

Table 15-4 Average Per Unit Change in Annual Energy Use, Ohio
 

Building Standard Edition 

Type LEC 

kWh/m2 kBtu/ft2 

APART04 -15.7 -5.0 

APART06 -17.2 -5.5 

DORMI04 -14.4 -4.6 

DORMI06 -18.4 -5.8 

HOTEL15 -20.2 -6.4 

HIGHS02 -19.8 -6.3 

OFFIC03 -13.8 -4.4 

OFFIC08 -18.4 -5.8 

OFFIC16 -23.2 -7.4 

RETAIL1 -15.6 -5.0 

RSTRNT1 -39.9 -12.7 

The adoption of the LEC design as the state’s energy code for commercial buildings 

would save energy for all building types and 47.8 GWh (163.2 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 57.8 % 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 statewide savings to 

be 82.7 GWh (282.3 GBtu) per year. These savings imply 826.8 GWh (2823.2 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. The greatest total reductions are realized by retail stores and 

high schools because they represent 36.2 % and 31.4 %, respectively, of the new 

construction in the state while all other building types represent 7.6 % or less. The 

amount of new construction overwhelms the relative percentage changes in energy use. 

For example, 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 

15-2. 

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Ohio 

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

Ohio 

Building Subcategory m 2 ft2 Standard Edition 

Type Weighting (1000s) (1000s) LEC 

kWh kBtu 

APART04 44.9 % 57.1 614 -895 330 -3 057 042
 

APART06 55.1 % 69.9 752 -1 201 296 -4 101 743
 

HOTEL15 100.0 % 185.0 1992 -3 739 195 -12 767 220 

HIGHS02 100.0 % 890.4 9584 -12 275 926 -41 915 289 

OFFIC03 37.4 % 200.2 2154 -3 957 577 -13 512 868 

OFFIC08 40.4 % 215.8 2323 -3 962 034 -13 528 088 

OFFIC16 22.2 % 118.8 1278 -2 761 081 -9 427 519 

RETAIL1 100.0 % 1026.5 11 049 -16 028 204 -54 727 181 

RSTRNT1 100.0 % 74.4 801 -2 970 162 -10 141 412 

Total 2838.0 30 548 -47 790 806 -163 178 362 

Note: Dormitories are excluded because no such floor area category is reported 

in the construction data. 

15.2.2 Energy Costs 

Table 15-6 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 15-6 Average Per Unit Change in Energy Costs, 10-Year, Ohio 

Building Standard Edition 

Type LEC 

$/m2 $/ft2 

APART04 -$13.23 -$1.23 

APART06 -$15.33 -$1.42 

DORMI04 -$11.15 -$1.04 

DORMI06 -$16.27 -$1.51 

HOTEL15 -$15.83 -$1.47 

HIGHS02 -$16.43 -$1.53 

OFFIC03 -$16.08 -$1.49 

OFFIC08 -$14.89 -$1.38 

OFFIC16 -$19.43 -$1.80 

RETAIL1 -$12.23 -$1.14 

RSTRNT1 -$32.31 -$3.00 

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. All building types realize energy cost savings for the LEC design, with a 

statewide reduction in energy costs of $42.8 million for 10 years of building operation. 

134
 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Ohio 

Assuming that the buildings considered in this study, which represent 57.8 % 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 the LEC design can be extrapolated 

to estimate the total statewide energy cost savings of $74.1 million over the 10-year study 

period. 

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

10-Year, Ohio 

Building Subcategory m 2 ft2 Standard Edition
 

Type Weighting (1000s) (1000s) LEC
 

APART04 44.9 % 57.1 614 -$754 715 

APART06 55.1 % 69.9 752 -$1 071 102 

HOTEL15 100.0 % 185.0 1992 -$2 929 604 

HIGHS02 100.0 % 890.4 9584 -$14 317 011 

OFFIC03 37.4 % 200.2 2154 -$3 289 486 

OFFIC08 40.4 % 215.8 2323 -$3 213 562 

OFFIC16 22.2 % 118.8 1278 -$2 306 878 

RETAIL1 100.0 % 1026.5 11 049 -$12 554 631 

RSTRNT1 100.0 % 74.4 801 -$2 403 926 

Total 2838.0 30 548 -$42 840 916 

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. The carbon emissions estimation approach is defined 

in Section 5.3. 

Table 15-8 Average Per Unit Change in Carbon Emissions, 10-Year, Ohio 

Building Standard Edition 

Type LEC 

kg/m2 lb/ft2 

APART04 -148.6 -30.4 

APART06 -173.1 -35.5 

DORMI04 -124.1 -25.4 

DORMI06 -183.6 -37.6 

HOTEL15 -176.5 -36.2 

HIGHS02 -185.6 -38.0 

OFFIC03 -184.4 -37.8 

OFFIC08 -166.6 -34.1 

OFFIC16 -218.0 -44.7 

RETAIL1 -136.4 -27.9 

RSTRNT1 -361.5 -74.0 

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Ohio 

Table 15-9 applies the Table 15-8 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 484 121 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 837 580 metric tons over the 

10-year study period. 

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

Construction, 10-Year, Ohio – Metric Tons 

Building Subcategory m 2 ft2 Standard Edition
 

Type Weighting (1000s) (1000s)
 LEC 

APART04 44.9 % 57.1 614 -8479 

APART06 55.1 % 69.9 752 -12 098 

HOTEL15 100.0 % 185.0 1992 -32 667 

HIGHS02 100.0 % 890.4 9584 -165 230 

OFFIC03 37.4 % 200.2 2154 -36 904 

OFFIC08 40.4 % 215.8 2323 -35 963 

OFFIC16 22.2 % 118.8 1278 -25 894 

RETAIL1 100.0 % 1026.5 11 049 -139 989 

RSTRNT1 100.0 % 74.4 801 -26 897 

Total 2838.0 30 548 -484 121 

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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Ohio 

Table 15-10 Average Per Unit Change in Life-Cycle Costs, 10-Year, Ohio
 

Building Standard Edition 

Type LEC 

$/m2 $/ft2 

APART04 $5.23 $0.49 

APART06 $4.19 $0.39 

DORMI04 -$11.45 -$1.06 

DORMI06 $1.11 $0.10 

HOTEL15 $4.11 $0.38 

HIGHS02 -$7.14 -$0.66 

OFFIC03 -$20.98 -$1.95 

OFFIC08 -$18.92 -$1.76 

OFFIC16 $3.69 $0.34 

RETAIL1 -$3.22 -$0.30 

RSTRNT1 -$46.12 -$4.28 

Table 15-11 applies the Table 6-10 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 5 of 9 building types realizing reductions in life-cycle costs. 

Overall, the LEC design results in a decrease of $19.6 million in statewide life-cycle 

costs relative to ASHRAE 90.1-2007. High schools, 3-story office buildings, and 8-story 

office buildings realize the greatest statewide decreases in life-cycle costs ($6.4 million, 

$4.2 million, and $4.1 million, respectively) while hotels and 16-story office buildings 

realize the greatest increases in life-cycle costs ($760 121 and $438 543, 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 $33.9 million over the 

10-year study period. 

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Ohio 

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

10-Year, Ohio 

Building Subcategory m 2 ft2 Standard Edition
 

Type Weighting (1000s) (1000s) LEC
 

APART04 44.9 % 57.1 614 $298 431
 

APART06 55.1 % 69.9 752 $292 876
 

HOTEL15 100.0 % 185.0 1992 $760 121 

HIGHS02 100.0 % 890.4 9584 -$6 355 737 

OFFIC03 37.4 % 200.2 2154 -$4 199 547 

OFFIC08 40.4 % 215.8 2323 -$4 083 527 

OFFIC16 22.2 % 118.8 1278 $438 543 

RETAIL1 100.0 % 1026.5 11 049 -$3 308 504 

RSTRNT1 100.0 % 74.4 801 -$3 430 813 

Total 2838.0 30 548 -$19 588 158 

Note: Dormitories are excluded because no such floor area category is 

reported in the construction data. 

15.3 State Summary 

Ohio 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 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 826.8 GWh (2823.2 GBtu), energy cost savings of 

$74.1 million, and carbon emissions reductions of 837 580 metric tons while decreasing 

life-cycle costs by $33.9 million for one year’s worth of commercial building 

construction. 

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South Dakota 

16 South Dakota 

South Dakota is located in the West North Central Census Division, and spans two 

climate zones (Zone 5 and Zone 6). 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 16-1 provides an overview of 

South Dakota’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 95 kWh/m2 to 130 kWh/m2 

(30 kBtu/ft2 to 41 kBtu/ft2) annually. The high school uses the greatest amount of energy 

at 280 kWh/m2 to 314 kWh/m2 (89 kBtu/ft2 to 100 kBtu/ft2) annually. 

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

South Dakota 

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 

215 68 

212 67 

214 68 

211 67 

197 63 

194 62 

188 60 

186 59 

170 54 

168 53 

DORMI04 

DORMI06 

174 55 

230 73 

172 54 

229 73 

161 51 

211 67 

150 48 

208 66 

132 42 

190 60 

HOTEL15 207 66 206 65 191 61 200 64 182 58 

HIGHS02 314 100 313 99 308 98 298 95 280 89 

OFFIC03 

OFFIC08 

OFFIC16 

146 46 

130 41 

185 59 

144 46 

128 41 

183 58 

137 44 

120 38 

176 56 

127 40 

114 36 

186 59 

105 33 

95 30 

166 53 

RETAIL1 175 56 173 55 164 52 146 46 122 39 

RSTRNT1 248 79 244 77 231 73 198 63 151 48 

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. 

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 more energy efficient designs for the state of South Dakota. 

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South Dakota 

16.1.1 Energy Use 

Table 16-2 shows 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 1.3 % or less. 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 -1.9 % to -8.3 % with 

an average of -6.5 %. The average change in energy use from constructing buildings 

using ASHRAE 90.1-2007 requirements ranges from 1.2 % to -19.9 %, with an overall 

average of -10.5 %. 

Table 16-2 Average Percentage Change in Energy Use from Adoption of Newer 

Standard Editions, South Dakota 

Building Standard Edition 

Type 2001 2004 2007 LEC 

APART04 -0.3 -8.2 -12.5 -21.2 

APART06 -0.3 -8.3 -12.1 -20.6 

DORMI04 -0.9 -7.3 -13.1 -24.0 

DORMI06 -0.3 -8.2 -9.6 -17.3 

HOTEL15 -0.5 -7.6 -3.0 -11.8 

HIGHS02 -0.3 -1.9 -5.0 -10.9 

OFFIC03 -1.0 -5.8 -12.6 -28.1 

OFFIC08 -1.3 -7.7 -12.4 -26.8 

OFFIC16 -0.5 -4.3 1.2 -10.1 

RETAIL1 -0.7 -6.3 -16.1 -29.9 

RSTRNT1 -1.1 -6.5 -19.9 -39.0 

Average -0.7 -6.5 -10.5 -21.8 

The ASHRAE 90.1-2007 design realizes an increase for the 16-story office building. 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 South Dakota, 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. For the 

ASHRAE 90.1-2007 design, the 16-story office building realizes a small percentage 

increase in energy use (1.2 %) while the hotel realizes a small decrease relative to 

ASHRAE 90.1-1999. The maximum window SHGC in Zone 5 and Zone 6 is increased 

from ASHRAE 90.1-2004 to ASHRAE 90.1-2007, making the requirement less strict. 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 Rvalues. 

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South Dakota 

The LEC design realizes the greatest reductions in energy use, with the change in energy 

use relative to ASHRAE 90.1-1999 ranging from -10.1 % to -39.0 % with an average 

of -21.8 %. 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 ratio due to 

the less strict window SHGC requirement. 

16.1.2 Energy Costs 

Table 16-3 shows minimal change in energy costs over 10 years from adopting ASHRAE 

90.1-2001 (-0.5 % to -1.6 %), 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 -6.4 % to -19.5 % depending on the building type, 

with an average of -14.2 %. The average change in energy costs from constructing 

buildings using ASHRAE 90.1-2007 requirements ranges from -1.5 % to -20.9 %, with an 

overall average of -15.7 %. The LEC design realizes the greatest change in energy costs, 

with the average change by building type ranging from -13.2 % to -43.6 % with an 

average of -29.5 % overall. 

Table 16-3 Average Percentage Change in Energy Costs, 10-Year, South Dakota 

Building Standard Edition 

Type 2001 2004 2007 LEC 

APART04 -0.5 -19.2 -21.9 -34.1 

APART06 -0.5 -19.2 -21.6 -33.5 

DORMI04 -1.3 -19.5 -22.7 -35.7 

DORMI06 -0.5 -19.0 -19.8 -30.6 

HOTEL15 -0.7 -17.6 -12.1 -21.8 

HIGHS02 -0.5 -6.4 -8.7 -20.0 

OFFIC03 -1.3 -9.7 -12.8 -30.2 

OFFIC08 -1.5 -11.0 -12.9 -28.4 

OFFIC16 -0.7 -7.8 -1.5 -13.2 

RETAIL1 -0.9 -12.8 -18.4 -33.5 

RSTRNT1 -1.6 -13.5 -20.9 -43.6 

Average -0.9 -14.2 -15.7 -29.5 

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 reduced 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. 

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South Dakota 

16.1.3 Energy-related Carbon Emissions 

Minimal change in energy use leads to small reductions (1.6 % or less) in cradle-to-grave 

energy-related carbon emissions for the ASHRAE 90.1-2001 design across all building 

types. Table 16-4 shows a significant change in energy-related carbon emissions for 

ASHRAE 90.1-2004 across building types, ranging from -7.3 % to -21.3 % with an 

average of -15.2 %. 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 -1.8 % to -24.0 % with an overall average of -16.5 %. The LEC design leads to the 

greatest average carbon emissions changes, ranging from -13.6 % to -44.2 % depending 

on the building type with an average of -30.6 % across all building types. 

Table 16-4 Average Percentage Change in Energy-related Carbon Emissions, 10­

Year, South Dakota 

Building Standard Edition 

Type 2001 2004 2007 LEC 

APART04 -0.5 -20.8 -23.3 -35.9 

APART06 -0.5 -20.8 -22.9 -35.4 

DORMI04 -1.3 -21.3 -24.0 -37.3 

DORMI06 -0.5 -20.5 -21.3 -32.5 

HOTEL15 -0.7 -19.0 -13.4 -23.2 

HIGHS02 -0.5 -7.3 -9.4 -21.7 

OFFIC03 -1.3 -10.2 -12.8 -30.4 

OFFIC08 -1.5 -11.4 -12.9 -28.6 

OFFIC16 -0.7 -8.2 -1.8 -13.6 

RETAIL1 -1.0 -13.7 -18.7 -34.0 

RSTRNT1 -1.6 -14.5 -21.0 -44.2 

Average -0.9 -15.2 -16.5 -30.6 

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. This 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 South Dakota. 

16.1.4 Life-Cycle Costs 

The most cost-effective building design for each building type is bolded in Table 16-5. 

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 never 

the lowest cost building design while 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 

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South Dakota 

life-cycle costs for ASHRAE 90.1-2004 and -2007 range from -2.3 % to 2.4 % 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 -3.0 % to 

0.2 %. 

Table 16-5 Average Percentage Change in Life-Cycle Costs, 10-Year, South Dakota 

Building Standard Edition 

Type 2001 2004 2007 LEC 

APART04 0.0 -1.7 -2.2 -1.7 

APART06 0.0 -1.8 -2.1 -1.5 

DORMI04 2.3 -1.0 -1.2 -1.4 

DORMI06 0.0 -2.2 -2.3 -2.0 

HOTEL15 0.0 -2.3 -1.8 -1.3 

HIGHS02 0.3 -0.5 -0.9 -1.8 

OFFIC03 3.2 1.3 0.8 -0.7 

OFFIC08 3.2 1.1 0.7 -0.5 

OFFIC16 0.0 -0.9 -0.2 0.2 

RETAIL1 2.0 -0.4 -1.1 -0.9 

RSTRNT1 4.6 2.4 0.3 -3.0 

Average 1.4 -0.6 -0.9 -1.3 

16.1.5 City Comparisons 

Simulations are run for three cities located in South Dakota, all of which are located in 

Zone 6: Huron, Pierre, and Sioux Falls. While the three cities are located in the same 

climate zone, the results may still vary across cities within the state for three 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. Finally, Huron has adopted a stricter 

building energy code than the state. 

As can be seen in Table 16-6, the average reduction in energy use for all building types 

from adopting newer energy standard editions is smallest for Huron followed by Sioux 

Falls and Pierre. The variation is small even though the Huron has adopted ASHRAE 

90.1-2001 as its local energy code for commercial buildings. 

Table 16-6 Average Percentage Change in Energy Use from Adoption of Newer 

Standard Editions by City, South Dakota 

Cities Zone Standard Edition 

Huron 

Pierre 

Sioux Falls 

Average 

6A 

6A 

6A 

2001 

0.0 

-1.0 

-0.9 

-0.7 

2004 

-5.5 

-7.4 

-6.7 

-6.5 

2007 

-9.6 

-11.1 

-10.6 

-10.5 

LEC 

-20.8 

-22.7 

-21.9 

-21.8 

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South Dakota 

The variations in energy costs across cities are a result of three factors, the reduction in 

energy use, the fuel source of the reduction, and the city’s local energy code. Table 16-7 

shows that average reduction in energy costs for all building types is highly correlated 

with reductions in energy use. For all building designs, Huron realizes slightly lower 

reductions in energy costs. 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. 

Table 16-7 Average Percentage Change in Energy Costs by City, 10-Year, South 

Dakota 

Cities Zone Standard Edition 

2001 2004 2007 LEC 

Huron 6A 0.0 -13.1 -14.8 -28.5 

Pierre 6A -1.4 -15.0 -16.4 -30.3 

Sioux Falls 6A -1.3 -14.4 -16.0 -29.7 

Average -0.9 -14.2 -15.7 -29.5 

Table 16-8 reports changes in energy-related carbon emissions by city for South Dakota. 

For all three cities, the more stringent standard editions result in greater reductions in 

carbon emissions. As with the energy use, Huron realizes the smallest reductions in 

carbon emissions for all building designs. 

Table 16-8 Average Percentage Change in Carbon Emissions by City, 10-Year, 

South Dakota 

Cities Zone Standard Edition 

2001 2004 2007 LEC 

Huron 6A 0.0 -13.6 -15.3 -29.6 

Pierre 6A -1.3 -15.3 -16.8 -31.3 

Sioux Falls 6A -1.2 -14.9 -16.5 -30.7 

Average -0.8 -14.6 -16.2 -30.5 

The data reported in Table 16-9 show that, over a 10-year period, average life-cycle costs 

increase for Pierre and Sioux Falls from the adoption of the ASHRAE 90.1-2001 

and -2004 designs. Huron realizes average percentage reductions in life-cycle costs for 

the ASHRAE 90.1-2004, -2007, and LEC designs. Adopting the ASHRAE 90.1-2007 and 

LEC designs results in reductions in average life-cycle costs for Pierre and Sioux Falls. 

For all three cities, the LEC design is the most cost-effective building design alternative. 

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South Dakota 

Table 16-9 Average Percentage Change in Life-Cycle Costs by City, 10-Year, South 

Dakota 

Cities Zone Standard Edition 

2001 2004 2007 LEC 

Huron 6A 0.0 -1.9 -2.3 -2.7 

Pierre 6A 2.2 0.1 -0.3 -0.7 

Sioux Falls 6A 2.1 0.1 -0.2 -0.5 

Average 1.4 -0.6 -0.9 -1.3 

16.2 Total Savings 

How much can South Dakota 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 16-10 reports the average per unit change in annual energy use by building type 

and building design 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 16-11 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.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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South Dakota 

Table 16-10 Average Per Unit Change in Annual Energy Use, South Dakota
 

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 

-17.5 -5.6 

-17.6 -5.6 

-26.9 -8.5 

-25.6 -8.1 

-45.5 -14.4 

-43.6 -13.8 

DORMI04 

DORMI06 

-1.5 -0.5 

-0.8 -0.2 

-12.5 -4.0 

-18.7 -5.9 

-22.7 -7.2 

-22.0 -7.0 

-41.4 -13.1 

-39.8 -12.6 

HOTEL15 -0.9 -0.3 -15.6 -4.9 -6.1 -1.9 -24.3 -7.7 

HIGHS02 -0.8 -0.3 -8.3 -2.6 -18.3 -5.8 -40.8 -12.9 

OFFIC03 

OFFIC08 

OFFIC16 

-1.4 -0.5 

-1.7 -0.5 

-0.9 -0.3 

-5.8 -1.8 

-10.0 -3.2 

-7.9 -2.5 

-15.5 -4.9 

-16.1 -5.1 

2.2 0.7 

-34.2 -10.8 

-34.8 -11.0 

-18.5 -5.9 

RETAIL1 -1.2 -0.4 -11.0 -3.5 -28.2 -8.9 -52.2 -16.6 

RSTRNT1 -2.8 -0.9 -16.0 -5.1 -49.0 -15.5 -96.2 -30.5 

The total annual reduction in energy use ranges widely across building designs, but 

ASHRAE 90.1-2001, ASHRAE 90.1-2004, ASHRAE 90.1-2007, and LEC all decrease 

overall energy use across the state. Adopting ASHRAE 90.1-2001 results in an annual 

decrease of 755.1 MWh (221 172 kBtu) while adopting ASHRAE 90.1-2004 and 

ASHRAE 90.1-2007 save 1.9 GWh (6.4 GBtu) and 3.7 GWh (12.7 GBtu) annually, 

respectively. The adoption of the LEC design as the state’s energy code would save 

energy for all building types and 7.9 GWh (26.9 GBtu) of total energy use annually for 

one year’s worth of new construction for these building types. 

Table 16-11 Statewide Change in Annual Energy Use for One Year of Construction, 

South Dakota 

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 % 

1.2 

1.5 

13 

16 

-1 -3 

-1 -3 

-21 -71 

-26 -87 

-32 -109 

-37 -127 

-54 -184 

-63 -216 

HOTEL15 100.0 % 17.1 184 -16 -54 -267 -912 -105 -358 -416 -1419 

HIGHS02 100.0 % 53.6 577 -43 -148 -311 -1063 -829 -2832 -1830 -6249 

OFFIC03 

OFFIC08 

OFFIC16 

37.4 % 

40.4 % 

22.2 % 

19.2 

20.8 

11.4 

207 

223 

123 

-28 -95 

-34 -118 

-11 -37 

-161 -549 

-207 -705 

-90 -307 

-351 -1200 

-334 -1139 

26 88 

-785 -2681 

-722 -2464 

-211 -721 

RETAIL1 100.0 % 68.2 734 -80 -273 -748 -2554 -1 920 -6556 -3560 -12 157 

RSTRNT1 100.0 % 2.6 28 -7 -24 -41 -140 -126 -429 -247 -842 

Total 195.5 2104 -221 -755 -1871 -6389 -3 708 -12 661 -7888 -26 934 

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 64.5 % 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 the total 

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South Dakota 

statewide savings from adopting the LEC design in new commercial buildings to be 12.2 

GWh (41.8 GBtu) per year. These savings imply 122.3 GWh (417.6 GBtu) in energy use 

savings over the 10-year study period. In comparison, ASHRAE 90.1-2007 would save 

5.7 GWh (19.6 GBtu) annually or 57.5 GWh (196.3 GBtu) over the 10-year study period. 

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 greatest total reductions are realized by retail stores 

and high schools because they represent 34.9 % and 27.4 %, respectively, of the new 

construction in the state while all other building types represent less than 10.6 %. The 

amount of new construction overwhelms the relative percentage 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. 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 16-2. 

16.2.2 Energy Costs 

Table 16-12 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 16-12 Average Per Unit Change in Energy Costs, 10-Year, South Dakota 

Building Standard Edition 

Type 2001 

$/m2 $/ft2 

2004 

$/m2 $/ft2 

2007 

$/m2 $/ft2 

LEC 

$/m2 $/ft2 

APART04 

APART06 

-$0.39 

-$0.40 

-$0.04 

-$0.04 

-$16.04 

-$16.06 

-$1.49 

-$1.49 

-$18.34 

-$17.99 

-$1.70 

-$1.67 

-$28.51 

-$27.99 

-$2.65 

-$2.60 

DORMI04 

DORMI06 

-$0.87 

-$0.45 

-$0.08 

-$0.04 

-$13.41 

-$17.18 

-$1.25 

-$1.60 

-$15.58 

-$17.93 

-$1.45 

-$1.67 

-$24.51 

-$27.65 

-$2.28 

-$2.57 

HOTEL15 -$0.54 -$0.05 -$14.18 -$1.32 -$9.72 -$0.90 -$17.57 -$1.63 

HIGHS02 -$0.84 -$0.08 -$6.48 -$0.60 -$8.52 -$0.79 -$20.07 -$1.86 

OFFIC03 

OFFIC08 

OFFIC16 

-$0.47 

-$0.97 

-$0.55 

-$0.04 

-$0.09 

-$0.05 

-$6.61 

-$7.08 

-$6.30 

-$0.61 

-$0.66 

-$0.59 

-$8.93 

-$8.25 

-$1.18 

-$0.83 

-$0.77 

-$0.11 

-$20.58 

-$18.22 

-$10.65 

-$1.91 

-$1.69 

-$0.99 

RETAIL1 -$0.68 -$0.06 -$9.47 -$0.88 -$13.57 -$1.26 -$24.70 -$2.29 

RSTRNT1 -$1.62 -$0.15 -$13.90 -$1.29 -$21.46 -$1.99 -$44.73 -$4.16 

Table 16-13 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 ($128 438). Adopting the ASHRAE 90.1-2004, ASHRAE 90.1-2007, and 

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South Dakota 

LEC designs decrease energy costs by $1.7 million, $2.0 million, and $4.2 million 

respectively. The 16-story office building, which realizes an increase in total energy use 

from the adoption of the ASHRAE 90.1-2007 design, realizes a decrease in 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 64.5 % 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 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 $199 129, $2.6 million, $3.1 million, and 

$6.5 million over the 10-year study period, respectively. 

Table 16-13 Statewide Change in Energy Costs for One Year of Construction, 

10-Year, South Dakota 

Building Subcategory m 2 ft2 Standard Edition 

Type Weighting (1000s) (1000s) 2001 2004 2007 LEC 

APART04 44.9 % 1.2 13 -$467 -$19 021 -$21 746 -$33 808 

APART06 55.1 % 1.5 16 -$587 -$23 325 -$26 137 -$40 656 

HOTEL15 100 % 17.1 184 -$9226 -$242 858 -$166 498 -$300 995 

HIGHS02 100 % 53.6 577 -$25 231 -$354 075 -$478 315 -$1 102 594 

OFFIC03 37.4 % 19.2 207 -$16 139 -$124 616 -$163 979 -$386 210 

OFFIC08 40.4 % 20.8 223 -$20 034 -$146 894 -$171 146 -$378 037 

OFFIC16 22.2 % 11.4 123 -$6233 -$71 896 -$13 512 -$121 600 

RETAIL1 100 % 68.2 734 -$46 367 -$645 146 -$925 080 -$1 683 293 

RSTRNT1 100 % 2.6 28 -$4156 -$35 650 -$55 019 -$114 702 

Total 195.5 2104 -$128 438 -$1 663 481 -$2 021 431 -$4 161 896 

Note: Dormitories are excluded because no such floor area category is reported in the construction data. 

16.2.3 Energy-related Carbon Emissions 

Table 16-14 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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South Dakota 

Table 16-14 Average Per Unit Change in Carbon Emissions, 10-Year, South Dakota
 

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 

-6.0 -1.2 

-6.2 -1.3 

-254.9 -52.2 

-255.2 -52.3 

-285.7 -58.5 

-281.0 -57.6 

-441.1 -90.3 

-433.9 -88.9 

DORMI04 

DORMI06 

-13.3 -2.7 

-6.9 -1.4 

-214.9 -44.0 

-273.0 -55.9 

-242.9 -49.8 

-282.9 -58.0 

-377.4 -77.3 

-431.4 -88.4 

HOTEL15 -8.3 -1.7 -225.2 -46.1 -158.2 -32.4 -275.0 -56.3 

HIGHS02 -7.2 -1.5 -106.2 -21.7 -137.1 -28.1 -317.2 -65.0 

OFFIC03 

OFFIC08 

OFFIC16 

-12.9 -2.6 

-14.8 -3.0 

-8.4 -1.7 

-101.8 -20.9 

-110.6 -22.7 

-99.2 -20.3 

-128.0 -26.2 

-125.2 -25.6 

-21.8 -4.5 

-303.2 -62.1 

-277.1 -56.8 

-163.5 -33.5 

RETAIL1 -10.5 -2.1 -149.9 -30.7 -204.6 -41.9 -371.4 -76.1 

RSTRNT1 -24.9 -5.1 -220.2 -45.1 -319.7 -65.5 -671.4 -137.5 

Table 16-15 applies the Table 16-14 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 90.1-2001, ASHRAE 90.1-2004, 

ASHRAE 90.1-2007, and LEC designs decrease carbon emissions overall. The adoption 

of ASHRAE 90.1-2001, -2004, and -2007 result in savings of 1974 metric tons, 26 389 

metric tons, and 30 873 metric tons over a 10-year study period, respectively. The 16­

story office building, which realizes an increase in total energy use from adopting 

ASHRAE 90.1-2007, realizes a decrease in carbon emissions because the emissions 

resulting from the increase in natural gas consumption are less than the decrease in 

emissions from electricity consumption. The adoption of LEC as the state’s energy code 

decreases carbon emissions by 63 352 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 90.1-2001, ASHRAE 

90.1-2004, ASHRAE 90.1-2007, and LEC designs can be extrapolated to estimate 

statewide reductions in carbon emissions of 3060 metric tons, 40 913 metric tons, 47 865 

metric tons, and 98 221 metric tons over the 10-year study period, respectively. 

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South Dakota 

Table 16-15 Statewide Change in Total Carbon Emissions for One Year of 

Construction, 10-Year, South Dakota – Metric Tons 

Building Subcategory m 2 ft2 Standard Edition 

Type Weighting (1000s) (1000s) 2001 2004 2007 LEC 

APART04 44.9 % 1.2 13 -7 -302 -339 -523 

APART06 55.1 % 1.5 16 -9 -371 -408 -630 

HOTEL15 100.0 % 17.1 184 -142 -3858 -2710 -4711 

HIGHS02 100.0 % 53.6 577 -388 -5689 -7345 -17 000 

OFFIC03 37.4 % 19.2 207 -248 -1960 -2462 -5,835 

OFFIC08 40.4 % 20.8 223 -308 -2296 -2598 -5,750 

OFFIC16 22.2 % 11.4 123 -96 -1133 -248 -1,867 

RETAIL1 100.0 % 68.2 734 -712 -10 216 -13 943 -25 315 

RSTRNT1 100.0 % 2.6 28 -64 -565 -820 -1722 

Total 195.5 2104 -1974 -26 389 -30 873 -63 352 

Note: Dormitories are excluded because no such floor area category is reported in the 

construction data. 

16.2.4 Life-Cycle Costs 

Table 16-16 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 16-16 Average Per Unit Change in Life-Cycle Costs, 10-Year, South Dakota 

Building Standard Edition 

Type 2001 

$/m2 $/ft2 

2004 

$/m2 $/ft2 

2007 

$/m2 $/ft2 

LEC 

$/m2 $/ft2 

APART04 $0.26 $0.02 -$15.33 -$1.42 -$19.41 -$1.80 -$14.80 -$1.37 

APART06 -$0.05 $0.00 -$15.54 -$1.44 -$18.54 -$1.72 -$13.32 -$1.24 

DORMI04 $18.97 $1.76 -$8.74 -$0.81 -$10.01 -$0.93 -$11.45 -$1.06 

DORMI06 -$0.25 -$0.02 -$20.38 -$1.89 -$21.48 -$2.00 -$18.50 -$1.72 

HOTEL15 -$0.34 -$0.03 -$20.05 -$1.86 -$15.39 -$1.43 -$11.51 -$1.07 

HIGHS02 $2.05 $0.19 -$4.02 -$0.37 -$6.64 -$0.62 -$13.10 -$1.22 

OFFIC03 $21.89 $2.03 $8.79 $0.82 $5.10 $0.47 -$5.41 -$0.50 

OFFIC08 $22.64 $2.10 $7.41 $0.69 $5.00 $0.46 -$3.51 -$0.33 

OFFIC16 -$0.11 -$0.01 -$5.98 -$0.56 -$1.52 -$0.14 $1.50 $0.14 

RETAIL1 $11.15 $1.04 -$2.59 -$0.24 -$6.40 -$0.59 -$4.98 -$0.46 

RSTRNT1 $51.16 $4.75 $25.74 $2.39 $2.26 $0.21 -$35.14 -$3.26 

Table 16-17 applies the Table 16-16 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. The total change in 

life-cycle costs over the 10-year study period varies across building designs. Adoption of 

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South Dakota 

the ASHRAE 90.1-2001 design results in an increase in life-cycle costs for 6 of 9 building 

types. The ASHRAE 90.1-2004 and -2007 designs result in a decrease in life-cycle costs 

for 6 of 9 building types, with total life-cycle costs decreasing by $455 599 and $915 667, 

respectively. The LEC design decreases life-cycle costs for 8 of 9 building types, and 

decreases total life-cycle costs by $1.5 million. For a 10-year study period, it is costeffective to adopt ASHRAE 90.1-2004, -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 $2.9 million, -$706 355, -$1.4 million, and -$2.4 million 

over the 10-year study period, respectively. 

Table 16-17 Statewide Change in Life-Cycle Costs for One Year of Construction, 

10-Year, South Dakota 

Building Subcategory m 2 ft2 Standard Edition 

Type Weighting (1000s) (1000s) 2001 2004 2007 LEC 

APART04 44.9 % 1.2 13 $310 -$18 176 -$23 024 -$17 546 

APART06 55.1 % 1.5 16 -$76 -$22 574 -$26 937 -$19 341 

HOTEL15 100.0 % 17.1 184 -$5 859 -$343 398 -$263 659 -$197 170 

HIGHS02 100.0 % 53.6 577 $109 975 -$215 562 -$355 960 -$701 783 

OFFIC03 37.4 % 19.2 207 $421 303 $169 176 $98 147 -$104 021 

OFFIC08 40.4 % 20.8 223 $469 749 $153 699 $103 763 -$72 774 

OFFIC16 22.2 % 11.4 123 -$1 260 -$68 269 -$17 370 $17 182 

RETAIL1 100.0 % 68.2 734 $759 704 -$176 484 -$436 429 -$339 655 

RSTRNT1 100.0 % 2.6 28 $131 177 $65 989 $5 801 -$90 112 

Total 195.5 2104 $1 885 024 -$455 599 -$915 667 -$1 525 220 

Note: Dormitories are excluded because no such floor area category is reported in the construction data. 

16.3 State Summary 

South Dakota is one of the four states in the Midwest Census Region that have no state 

energy code for commercial buildings. 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 use savings of 57.5 GWh (196.3 GBtu), energy cost savings of $3.1 million, and 

47 865 metric tons of carbon emissions reductions while saving $1.4 million in life-cycle 

costs for one year’s worth of commercial building construction. 

However, adopting the ASHRAE 90.1-2007 design increases energy use for 16-story 

office buildings in South Dakota. 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 

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South Dakota 

building envelope requirements (window U-factors and insulation R-values) are slightly 

less stringent for cities in Zone 6. Additionally, ASHRAE 90.1-2007 relaxes the window 

SHGC above that required in ASHRAE 90.1-2004 for South Dakota. 

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 lead to even greater impacts than adopting ASHRAE 90.1-2007, with 

savings of 122.3 GWh (417.6 GBtu), $6.5 million of energy costs, 98 221 metric tons of 

carbon emissions, and $2.4 million in life-cycle costs for one year’s worth of commercial 

building construction. 

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Wisconsin 

17 Wisconsin 

Wisconsin has adopted ASHRAE 90.1-2007 as its state energy code for commercial 

buildings, is located in the East North Central Census Region, and spans two climate 

zones (Zone 6A and Zone 7). Table 17-1 provides an overview of Wisconsin’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 93 kWh/m2 to 111 kWh/m2 (29 kBtu/ ft2 to 35 kBtu/ft2

) annually. The high 

school uses the greatest amount of energy at 282 kWh/m2 to 300 kWh/m2 (90 kBtu/ft2 to 

95 kBtu/ft2

) annually. 

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

Wisconsin 

Building 

Type 

Standard Edition 

2007 

kWh/m2 kBtu/ft2 

LEC 

kWh/m2 kBtu/ft2 

APART04 

APART06 

189 60 

187 59 

171 54 

170 54 

DORMI04 

DORMI06 

150 48 

209 66 

132 42 

192 61 

HOTEL15 201 64 183 58 

HIGHS02 300 95 282 90 

OFFIC03 

OFFIC08 

OFFIC16 

124 39 

111 35 

183 58 

102 32 

93 29 

163 52 

RETAIL1 143 45 120 38 

RSTRNT1 191 61 146 46 

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 cityby-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 in the state of Wisconsin. 

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. 

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Wisconsin 

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 -23.6 % depending on the building type with 

an overall average of -12.6 %. High schools realize the lowest reductions in energy use 

while restaurants realize the greatest reductions in energy use. 

Table 17-2 Average Percentage Change from Adoption of the LEC design, 10-Year, 

Wisconsin 

Building LEC 

Type Energy Use Energy Cost Carbon LCC 

APART04 -9.5 -15.9 -16.4 0.4 

APART06 -9.3 -15.5 -16.0 0.5 

DORMI04 -12.0 -17.0 -17.4 -0.8 

DORMI06 -8.2 -13.7 -14.2 0.2 

HOTEL15 -8.9 -11.2 -11.4 0.4 

HIGHS02 -5.9 -12.7 -13.4 -1.1 

OFFIC03 -17.5 -20.1 -20.2 -1.7 

OFFIC08 -16.4 -18.0 -18.1 -1.2 

OFFIC16 -10.9 -11.9 -12.0 0.3 

RETAIL1 -15.9 -18.0 -18.1 -1.1 

RSTRNT1 -23.6 -28.7 -29.1 -3.3 

Average -12.6 -16.6 -16.9 -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 -11.2 % to -28.7 % depending 

on the building type with an average of -16.6 % 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 the high school, adopting the LEC design increases natural gas 

consumption while decreasing electricity consumption. The increase in natural gas 

consumption offsets 13.2 % of the reduction in electricity consumption, and results in the 

percentage reduction in energy costs to be over twice the percentage reduction in energy 

use. The LEC design incorporates daylighting and overhangs into the building design, 

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 -11.4 % to -29.1 % with an average of -16.9 %. For the LEC design, the percentage 

reduction in carbon emissions is slightly 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 

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Wisconsin 

reduction in electricity consumption further decreases 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 -3.3 % to 0.5 % for a 10-year study period with 6 of the 11 building types realizing 

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. 

17.1.2 City Comparisons 

Simulations are run for five cities located in Wisconsin, all located in Zone 6A: Eau 

Claire, Green Bay, La Crosse, Madison, and Milwaukee. While the selected 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 17-3 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 do not vary significantly across cities, ranging from 

-12.1 % to -12.8 % with an overall average of -12.6 %. Any variation in local climate 

appears to have minimal effects on energy consumption. 

Table 17-3 Average Percentage Change in Energy Use from Adoption of the LEC 

Design by City, Wisconsin 

Cities Zone LEC 

Energy Use Energy Cost Carbon LCC 

Eau Claire 6A -12.1 -16.1 -16.7 -0.7 

Green Bay 6A -12.4 -16.5 -17.1 -0.8 

La Crosse 6A -12.7 -16.6 -17.2 -0.5 

Madison 6A -12.8 -16.8 -17.3 -0.7 

Milwaukee 6A -12.8 -16.7 -17.3 -0.6 

Average -12.6 -16.6 -17.1 -0.7 

The average percentage change in energy costs for all building types also varies 

minimally across cities, ranging from -16.1 % to -16.8 % 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 minimally across cities, ranging from -16.7 % 

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Wisconsin 

to -17.3 %. Reductions in life-cycle costs for all building types vary minimally across 

cities, with the percentage change ranging from -0.5 % to -0.8 %. 

17.2 Total Savings 

How much can Wisconsin 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 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 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.37 

Table 17-4 Average Per Unit Change in Annual Energy Use, Wisconsin 

Building Standard Edition 

Type LEC 

kWh/m2 kBtu/ft2 

APART04 -17.9 -5.7 

APART06 -17.4 -5.5 

DORMI04 -178.0 -5.7 

DORMI06 -17.2 -5.5 

HOTEL15 -17.8 -5.6 

HIGHS02 -21.8 -6.9 

OFFIC03 -17.6 -5.6 

OFFIC08 -18.2 -5.8 

OFFIC16 -20.0 -6.3 

RETAIL1 -22.7 -7.2 

RSTRNT1 -44.9 -14.3 

The adoption of the LEC design as the state’s energy code for commercial buildings 

would save energy for all building types and 28.0 GWh (95.6 GBtu) of total energy use 

annually for one year’s worth of new construction for these building types. Assuming that 

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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Wisconsin 

the buildings considered in this study, which represent 57.0 % 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 

be 49.1 GWh (167.6 GBtu) per year. These savings imply 491.0 GWh (1676.3 GWh) 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 36.6 % and 16.6 %, respectively, of the new 

construction in the state while all other building types represent 9.3 % 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 4th and 11th in percentage 

reduction, respectively, among the 11 building types, as reported in Table 17-2. 

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

Wisconsin 

Building Subcategory m 2 ft2 Standard Edition 

Type Weighting (1000s) (1000s) LEC 

kWh kBtu 

APART04 44.9 % 81 877 -1 460 482 -4 986 715 

APART06 55.1 % 100 1074 -1 733 043 -5 917 355 

HOTEL15 100.0 % 117 1255 -2 069 204 -7 065 153 

HIGHS02 100.0 % 226 2430 -3 977 568 -13 581 126 

OFFIC03 37.4 % 117 1254 -2 534 616 -8 654 268 

OFFIC08 40.4 % 126 1352 -2 279 698 -7 783 868 

OFFIC16 22.2 % 69 744 -1 382 125 -4 719 170 

RETAIL1 100.0 % 498 5359 -11 317 290 -38 642 095 

RSTRNT1 100.0 % 27 295 -1 230 620 -4 201 865 

Total 1360 14 639 -27 984 646 -95 551 615 

Note: Dormitories are excluded because no such floor area category is reported 

in the construction data. 

17.2.2 Energy Costs 

Table 17-6 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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Wisconsin 

Table 17-6 Average Per Unit Change in Energy Costs, 10-Year, Wisconsin
 

Building Standard Edition 

Type LEC 

$/m2 $/ft2 

APART04 -$13.26 -$1.23 

APART06 -$12.99 -$1.21 

DORMI04 -$11.46 -$1.06 

DORMI06 -$12.68 -$1.18 

HOTEL15 -$10.13 -$0.94 

HIGHS02 -$15.17 -$1.41 

OFFIC03 -$14.99 -$1.39 

OFFIC08 -$13.00 -$1.21 

OFFIC16 -$12.09 -$1.12 

RETAIL1 -$13.91 -$1.29 

RSTRNT1 -$29.49 -$2.74 

Table 17-7 reports the statewide changes in total energy costs by building type for the 

LEC 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 $18.9 million for 10 years of building operation. Assuming 

that the buildings considered in this study, which represent 57.0 % 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 

the total statewide energy cost savings of $33.2 million over the 10-year study period. 

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

10-Year, Wisconsin 

Building Subcategory m 2 ft2 Standard Edition
 

Type Weighting (1000s) (1000s) LEC
 

APART04 44.9 % 81 877 -$1 079 803 

APART06 55.1 % 100 1074 -$1 296 271 

HOTEL15 100.0 % 117 1255 -$1 180 194 

HIGHS02 100.0 % 226 2430 -$3 425 643 

OFFIC03 37.4 % 117 1254 -$1 745 771 

OFFIC08 40.4 % 126 1352 -$1 633 430 

OFFIC16 22.2 % 69 744 -$835 570 

RETAIL1 100.0 % 498 5359 -$6 923 358 

RSTRNT1 100.0 % 27 295 -$807 577 

Total 1360 14 639 -$18 927 617 

Note: Dormitories are excluded because no such floor area category 

is reported in the construction data. 

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Wisconsin 

17.2.3 Energy-related Carbon Emissions 

Table 17-8 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 17-8 Average Per Unit Change in Carbon Emissions, 10-Year, Wisconsin 

Building Standard Edition 

Type LEC 

kg/m2 lb/ft2 

APART04 -153.9 -31.5 

APART06 -150.9 -30.9 

DORMI04 -131.9 -27.0 

DORMI06 -147.2 -30.2 

HOTEL15 -115.8 -23.7 

HIGHS02 -177.4 -36.3 

OFFIC03 -173.3 -35.5 

OFFIC08 -150.7 -30.9 

OFFIC16 -138.8 -28.4 

RETAIL1 -159.7 -32.7 

RSTRNT1 -340.1 -69.7 

Table 17-9 applies the Table 17-8 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 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 218 699 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 383 682 metric tons over the 10­

year study period. 

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Wisconsin 

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

Construction, 10-Year, Wisconsin – Metric Tons 

Building Subcategory m 2 ft2 Standard Edition
 

Type Weighting (1000s) (1000s)
 LEC 

APART04 44.9 % 81 877 -12 536 

APART06 55.1 % 100 1074 -15 055 

HOTEL15 100.0 % 117 1255 -13 501 

HIGHS02 100.0 % 226 2430 -40 043 

OFFIC03 37.4 % 117 1254 -20 191 

OFFIC08 40.4 % 126 1352 -18 927 

OFFIC16 22.2 % 69 744 -9591 

RETAIL1 100.0 % 498 5359 -79 534 

RSTRNT1 100.0 % 27 295 -9321 

Total 1360 14 639 -218 699 

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. 

Table 17-10 Average Per Unit Change in Life-Cycle Costs, 10-Year, Wisconsin 

Building Standard Edition 

Type LEC 

$/m2 $/ft2 

APART04 $4.42 $0.41 

APART06 $5.20 $0.48 

DORMI04 -$8.05 -$0.75 

DORMI06 $2.48 $0.23 

HOTEL15 $3.87 $0.36 

HIGHS02 -$9.40 -$0.87 

OFFIC03 -$13.92 -$1.29 

OFFIC08 -$10.53 -$0.98 

OFFIC16 $2.76 $0.26 

RETAIL1 -$7.40 -$0.69 

RSTRNT1 -$45.18 -$4.20 

Table 17-11 applies the Table 17-10 results to one year’s worth of new building 

construction in the state to estimate statewide life-cycle cost changes from adoption of 

the LEC design. Total changes in life-cycle costs over the 10-year study period vary 

across building type, with 5 of 9 building types realizing reductions in life-cycle costs. 

Overall, the LEC design results in a decrease of $8.5 million in statewide life-cycle costs 

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Wisconsin 

relative to ASHRAE 90.1-2007. The 6-story apartment buildings and hotels realize the 

greatest statewide increases in life-cycle costs ($518 369 and $450 877, respectively) 

while retail stores realize the greatest decrease in life-cycle costs ($3.7 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 life-cycle cost decrease of $14.9 million over the 

10-year study period. 

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

10-Year, Wisconsin 

Building Subcategory m 2 ft2 Standard Edition
 

Type Weighting (1000s) (1000s) LEC
 

APART04 44.9 % 81 877 $359 919
 

APART06 55.1 % 100 1074 $518 369
 

HOTEL15 100.0 % 117 1255 $450 877 

HIGHS02 100.0 % 226 2430 -$2 122 267 

OFFIC03 37.4 % 117 1254 -$1 621 064 

OFFIC08 40.4 % 126 1352 -$1 322 856 

OFFIC16 22.2 % 69 744 $191 013 

RETAIL1 100.0 % 498 5359 -$3 684 303 

RSTRNT1 100.0 % 27 295 -$1 237 360 

Total 1360 14 639 -$8 467 672 

Note: Dormitories are excluded because no such floor area category is 

reported in the construction data. 

17.3 State Summary 

Wisconsin 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 energyrelated 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 491.0 GWh (1676.3 GWh), energy cost savings of 

$33.2 million, and carbon emissions reductions of 383 682 metric tons while decreasing 

life-cycle costs by $14.9 million for one year’s worth of commercial building 

construction. 

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State Comparisons for the Adoption of the Low Energy Case Design 

18 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 

Midwest 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 lifecycle 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 four states with no state energy code would realize greater 

benefits from adopting the LEC design relative to the other eight states in the Midwest 

Census Region that have adopted the more energy efficient ASHRAE 90.1-2004 and 

ASHRAE 90.1-2007. 

18.1 Total Savings Comparison 

By comparing the aggregate results from the detailed state-by-state analysis, some 

interesting trends emerge. Table 18-1 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 Midwest 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. 

163
 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

State Comparisons for the Adoption of the Low Energy Case Design 

Table 18-1 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) 

IA 2007 1447 (15 573) 283.7 17.6 256.4 4.0 

IL 2007 6929 (74 579) 1212.7 124.4 1343.5 31.4 

IN 2007 3663 (39 425) 656.9 49.8 652.7 13.3 

KS None 1077 (11 590) 438.6 28.6 436.0 2.3 

MI 2007 2964 (31 905) 511.9 40.4 490.9 17.0 

MN 2004 2329 (25 068) 816.7 33.5 443.8 12.4 

MO None 2358 (25 383) 984.7 56.9 1000.6 2.7 

ND None 229 (2464) 104.5 4.8 75.8 0.0 

NE 2007 920 (9900) 170.8 11.1 166.6 1.4 

OH 2007 4907 (52 814) 826.8 74.1 837.6 33.9 

SD None 303 (3262) 122.3 6.5 98.2 2.4 

WI 2007 2386 (25 679) 491.0 33.2 383.7 14.8 

Total 29 510 (317 641) 6620.6 458.5 6218.8 135.6 

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. 

Consider the reductions in energy use for three states with nearly identical amounts of 

new floor area, Minnesota, Missouri, and Wisconsin. Of these three states, Missouri 

realizes the greatest total reduction in energy use (984.7 GWh) followed by Minnesota 

(816.7 GWh) and Wisconsin (491.0 GWh). Even though Wisconsin has slightly more 

new floor area construction than the other two states, both realize greater total reductions 

because both have not yet adopted ASHRAE 90.1-2007 while Wisconsin has already done 

so. 

Table 18-2 shows the reduction in energy use per unit of newly constructed floor area by 

state. The reduction in energy use per unit of floor area 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, ranging from 404 kWh/m2 (128 kBtu/ft2

) to 456 kWh/m2 

(145 kBtu/ft2), followed by the state that has adopted ASHRAE 90.1-2004 and realizes 

reductions of 351 kWh/m2 (111 kBtu/ft2

). The states that have adopted ASHRAE 

90.1-2007 realize reductions ranging from 168 kWh/m2 (53 kBtu/ft2) to 206 kWh/m2 

(65 kBtu/ft2). 

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State Comparisons for the Adoption of the Low Energy Case Design 

Table 18-2 Energy Use Reduction per Unit of Floor Area for Adoption of the LEC 

Design by State, 10-Year 

State Code 

Floor 

Area 

Average Annual 

New Floor Area 

Energy Use Reduction 

Ranking 1000 m2 (1000 ft2

) GWh kWh/m2 kBtu/ft2 

ND 

MO 

KS 

SD 

None 

None 

None 

None 

49 

23 

35 

45 

229 (2464) 

2358 (25 383) 

1077 (11 590) 

303 (3262) 

104.5 456 145 

984.7 418 133 

438.6 407 129 

122.3 404 128 

MN 2004 24 2329 (25 068) 816.7 351 111 

WI 

IA 

NE 

IN 

IL 

MI 

OH 

2007 

2007 

2007 

2007 

2007 

2007 

2007 

22 

31 

36 

13 

5 

19 

7 

2386 (25 679) 

1447 (15 573) 

920 (9900) 

3663 (39 425) 

6929 (74 579) 

2964 (31 905) 

4907 (52 814) 

491.0 206 65 

283.7 196 62 

170.8 186 59 

656.9 179 57 

1212.7 175 56 

511.9 173 55 

826.8 168 53 

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 for the twelve states in the study. Table 18-3 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 reductions in electricity consumption offset by 

a change in natural gas consumption.38 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 

($0.03/kWh or $0.04/kWh) 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, Ohio (9.7¢/kWh) and Wisconsin (9.6¢/kWh) have similar electricity 

rates. However, Ohio realizes a greater average energy cost savings per unit of energy use 

savings ($0.09) than Wisconsin ($0.07) because Ohio realizes a shift in fuel consumption 

from electricity to natural gas, leading to additional savings. Meanwhile, Wisconsin 

realizes a reduction in both electricity and natural gas consumption, which dampens its 

savings per unit of reduction in energy use. 

38 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 18-3 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) 

IL 2007 11.6 11.3 2.5 0.10 

OH 2007 15.3 9.7 3.1 0.09 

MI 2007 3.7 9.2 2.7 0.08 

IN 2007 -13.6 8.3 2.7 0.08 

WI 2007 -25.9 9.6 2.6 0.07 

KS None 2.6 7.9 2.9 0.07 

IA 2007 -1.0 7.6 2.3 0.06 

NE 2007 9.6 7.3 2.2 0.06 

MO None 3.0 7.0 3.2 0.06 

SD None -14.6 7.1 2.2 0.05 

ND None -33.0 6.8 2.2 0.05 

MN 2004 -121.2 7.9 2.3 0.04 

*Percentage of the reduction in electricity consumption offset by change in 

natural gas consumption. 

Table 18-4 shows the weighted average fraction of reductions in electricity consumption 

offset by a change in natural gas consumption, the average CO2e 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. There is a direct correlation between the 

CO2e 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, five states have the same average emissions rate for electricity generation. The 

states with a greater offset in the reduction of electricity due to a change in natural gas 

realize a greater average reduction in carbon emissions. Additionally, Nebraska realizes 

greater average reductions in carbon emissions than Wisconsin even though its emissions 

rate for electricity is smaller, because Nebraska’s offset reflects an increase in natural gas 

consumption while Wisconsin’s reflects a decrease. 

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State Comparisons for the Adoption of the Low Energy Case Design 

Table 18-4 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) 

IL 2007 11.6 993 241 1108 

MO None 3.0 984 241 1016 

OH 2007 15.3 875 241 1013 

KS None 2.6 971 241 994 

IN 2007 13.6 875 241 994 

NE 2007 9.6 892 241 975 

MI 2007 3.7 909 241 959 

IA 2007 -1.0 892 241 904 

SD None -14.6 892 241 803 

WI 2007 -25.9 905 241 781 

ND None -33.0 892 241 725 

MN 2004 -121.2 892 241 543 

*Percentage of the reduction in electricity consumption offset by change in natural 

gas consumption. 

The relative change in life-cycle costs per unit of new floor area is shown in Table 18-5. 

There is no correlation between the energy cost savings (Table 18-3) and the life-cycle 

cost-effectiveness of adopting the LEC design because additional construction costs are 

required in order to obtain energy cost savings. All Midwest states realize an average 

decrease in life-cycle costs from adoption of the LEC design, with savings ranging from 

$0.08/m2 ($0.01/ft2

) to $7.92/m2 ($0.74/ft2). There is no correlation between the state 

energy code and the total statewide reduction in life-cycle costs. 

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State Comparisons for the Adoption of the Low Energy Case Design 

Table 18-5 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 

SD None 45 404 $2.4 $7.92 $0.74 

OH 2007 7 168 $33.9 $6.91 $0.64 

WI 2007 22 206 $14.8 $6.20 $0.58 

MI 2007 19 173 $17.0 $5.74 $0.53 

MN 2004 24 351 $12.4 $5.32 $0.49 

IL 2007 5 175 $31.4 $4.53 $0.42 

IN 2007 13 179 $13.3 $3.63 $0.34 

IA 2007 31 196 $4.0 $2.76 $0.26 

KS None 35 407 $2.3 $2.14 $0.20 

NE 2007 36 186 $1.4 $1.52 $0.14 

MO None 23 418 $2.7 $1.15 $0.11 

ND None 49 456 $0.0 $0.08 $0.01 

18.2 Percentage Savings Comparison 

State comparisons are made based on the simple average changes for the cities analyzed 

in each state by building type.39 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. 

18.2.1 3-Story Office Building 

Table 18-6 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 20 % each while reducing life-cycle costs by 

1.5 %. 

39 City-level data is not available to weight by amount of building construction in each city. 

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State Comparisons for the Adoption of the Low Energy Case Design 

Table 18-6 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 

IA -17.7 -21.4 -21.9 -1.7 

IL -17.5 -23.0 -23.0 -2.4 

IN -18.3 -22.4 -23.0 -2.1 

KS -31.9 -34.3 -35.1 0.7 

MI -16.4 -21.0 -21.5 -2.6 

MN -26.1 -23.7 -23.4 -1.8 

MO -31.6 -33.4 -34.4 1.4 

ND -29.5 -30.5 -30.6 0.8 

NE -18.2 -23.0 -23.5 -2.3 

OH -17.5 -22.1 -22.7 -2.5 

SD -28.1 -30.2 -30.4 -0.7 

WI -17.5 -20.1 -20.2 -1.7 

Avg. -21.4 -24.5 -24.9 -1.5 

These detailed results can be readily analyzed in mappings of the Midwest Census 

Region. Figure 18-1, Figure 18-2, Figure 18-3, and Figure 18-4 display the average 

percentage energy use savings, energy cost savings, carbon emissions reduction, and lifecycle cost savings by state, respectively. The states with no state energy code are shown 

with cross hatching and a bolded state border. Figure 18-1 shows that the states that have 

not yet adopted ASHRAE 90.1-2007 realize the greatest reductions in energy use. Kansas 

and Missouri realize energy use savings greater than 30 % by adopting the LEC design. 

Neither state currently has an energy code. North Dakota, South Dakota, and Minnesota 

realize reductions of 25 % to 30 %. None of the seven Midwestern states that have 

adopted ASHRAE 90.1-2007 realize energy use savings of greater than 20 %. 

Figure 18-1 Average Energy Use Savings by State, 3-Story Office Building, 10-Year 

Figure 18-2 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 %. All four states that 

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State Comparisons for the Adoption of the Low Energy Case Design 

have no state energy code realize energy cost savings of greater than 30 %. None of the 

other eight states have cost savings greater than 25 %. 

Figure 18-2 Average Energy Cost Savings by State, 3-Story Office Building, 

10-Year 

Figure 18-3 shows the average reductions in energy-related carbon emissions by state 

from adopting the LEC design. Similar to energy cost savings, the four states that have no 

state energy code realize reductions in carbon emissions of greater than 30 %. The other 

eight states realize reductions between 20 % and 25 %. 

Figure 18-3 Average Energy-related Carbon Emissions Reduction by State, 3-Story 

Office Building, 10-Year 

Figure 18-4 shows the average life-cycle cost savings over 10 years by state from 

adopting the LEC design. Three of the four states that have not adopted a state energy 

code realize increases in life-cycle costs while the fourth (South Dakota) realizes a small 

reduction in life-cycle costs (0.7 %). Of the states that have adopted ASHRAE 90.1-2004 

and -2007, three states realize reductions in life-cycle costs of less than 2 % while the 

other five states realize reductions in life-cycle costs between 2 % and 4 %. 

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State Comparisons for the Adoption of the Low Energy Case Design 

Figure 18-4 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 have 

the most to gain in percentage terms in energy use, energy cost, and carbon emissions 

savings from adopting the LEC design. Additionally, holding state energy codes constant, 

states in warmer climates would realize greater savings than states with colder climates. 

However, the benefits realized by states with no state energy code tend to not be 

life-cycle cost-effective. Of the four states with no state energy code, only South Dakota 

realizes a small percentage reduction in life-cycle costs. The other eight states would 

realize significant benefits from the adoption of the LEC design for 3-story office 

buildings, and do so in a cost-effective manner. 

18.2.2 Region-wide Results by Study Period Length 

The percentage change comparisons up to this point have 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 58 cities in the study ranges from 

7.6 % to 28.7 %, depending on the building type, with an overall regional average of 

16.1 %. Table 18-7 shows these results. 

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State Comparisons for the Adoption of the Low Energy Case Design 

Table 18-7 Midwest 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 

-13.0 

-13.5 

-15.4 

-12.8 

-11.9 

-7.6 

-21.4 

-20.8 

-13.1 

-18.8 

-28.7 

-16.1 

As shown in Table 18-8, 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 21.8 % for a 1-year study period to 

21.3 % 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 15.2 % to 34.9 %, depending on 

the building type, over all study periods. 

Table 18-8 Midwest 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 -20.5 -20.4 -20.4 -20.3 -20.2 -20.1 -20.0 -19.9 -19.9 

APART06 -22.0 -21.9 -21.8 -21.8 -21.7 -21.6 -21.5 -21.4 -21.3 

DORMI04 -21.9 -21.8 -21.7 -21.7 -21.6 -21.5 -21.5 -21.4 -21.3 

DORMI06 -20.9 -20.8 -20.7 -20.7 -20.6 -20.5 -20.4 -20.3 -20.2 

HOTEL15 -17.9 -17.8 -17.8 -17.7 -17.7 -17.6 -17.5 -17.5 -17.4 

HIGHS02 -16.0 -15.8 -15.8 -15.7 -15.6 -15.5 -15.4 -15.3 -15.2 

OFFIC03 -24.5 -24.5 -24.5 -24.5 -24.4 -24.4 -24.4 -24.3 -24.3 

OFFIC08 -22.6 -22.6 -22.6 -22.6 -22.6 -22.6 -22.6 -22.6 -22.5 

OFFIC16 -16.8 -16.8 -16.8 -16.8 -16.7 -16.7 -16.6 -16.6 -16.6 

RETAIL1 -21.5 -21.4 -21.4 -21.4 -21.4 -21.4 -21.3 -21.3 -21.3 

RSTRNT1 -34.9 -34.8 -34.8 -34.7 -34.7 -34.6 -34.5 -34.5 -34.4 

Average -21.8 -21.7 -21.7 -21.6 -21.6 -21.5 -21.4 -21.4 -21.3 

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 22.7 %. The 

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State Comparisons for the Adoption of the Low Energy Case Design 

regional average reduction in carbon emissions ranges from 17.4 % to 35.7 % depending 

on the building type, as shown in Table 18-9. 

Table 18-9 Midwest Region Average Percentage Change in Carbon Emissions by 

Building Type 

Building Percentage 

Type Change 

APART04 -21.9 

APART06 -23.5 

DORMI04 -23.0 

DORMI06 -22.3 

HOTEL15 -19.0 

HIGHS02 -17.6 

OFFIC03 -24.9 

OFFIC08 -22.8 

OFFIC16 -17.4 

RETAIL1 -21.8 

RSTRNT1 -35.7 

Average -22.7 

Table 18-10 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 18-10 Midwest 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 -1.7 0.0 0.0 -0.3 -0.1 -0.3 -0.4 -0.6 -0.5 

APART06 0.1 0.3 -0.0 -0.4 -0.3 -0.5 -0.6 -0.8 -0.7 

DORMI04 -5.7 -0.8 -0.6 -0.8 -0.6 -0.7 -0.8 -0.9 -0.8 

DORMI06 0.7 -0.1 -0.4 -0.8 -0.7 -0.9 -1.0 -1.2 -1.2 

HOTEL15 1.4 0.4 0.0 -0.4 -0.4 -0.7 -0.9 -1.1 -1.1 

HIGHS02 -1.1 -0.9 -1.0 -1.3 -1.3 -1.4 -1.6 -1.8 -1.7 

OFFIC03 -8.9 -1.8 -1.5 -1.7 -1.4 -1.5 -1.6 -1.7 -1.7 

OFFIC08 -3.3 -1.3 -1.3 -1.6 -1.3 -1.5 -1.6 -1.7 -1.7 

OFFIC16 2.0 1.0 0.5 -0.1 -0.0 -0.3 -0.5 -0.8 -0.7 

RETAIL1 -8.3 0.1 0.0 -0.4 0.0 -0.2 -0.4 -0.6 -0.5 

RSTRNT1 -10.0 -4.0 -3.4 -3.9 -3.5 -3.6 -3.8 -4.0 -4.1 

Average -3.2 -0.6 -0.7 -1.1 -0.9 -1.0 -1.2 -1.4 -1.3 

Figure 18-5 shows that four building types – the 6-story apartment building, 6-story 

dormitory, hotel, and 16-story office building – are not cost-effective for a 5-year study 

period, with an average change in life-cycle costs ranging from 0.0 % to 1.0 %. By a 15­

year study period, these four building types become cost-effective. The retail store is the 

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State Comparisons for the Adoption of the Low Energy Case Design 

only building type that is not cost-effective for all study periods longer than 10 years, 

realizing a 0.003 % increase in life-cycle costs for a 20-year study period. 

3.0 

APART04 2.0 

Change in Life-cycle Costs (%)
 

1.0 APART06 

0.0 DORMI04 

-1.0 

DORMI06 -2.0 

-3.0 HOTEL15 

-4.0 HIGHS02 

-5.0 

OFFIC03 -6.0 

-7.0 OFFIC08 

-8.0 OFFIC16 

-9.0 RETAIL1 -10.0 

-11.0 RSTRNT1 

Study Period 

Figure 18-5 Average Change in Life-Cycle Costs by Building Type and Study 

Period Length 

1 5 10 15 20 25 30 35 40
 

18.2.3 Region-wide Results by Building Type 

For a 10-year study period length, Table 18-11 shows the simple average changes across 

all 58 cities in the Midwest Census Region, in percentage terms, from adopting the LEC 

design. The building type that realizes the smallest percentage reductions in energy use, 

energy costs, and energy-related carbon emissions is the high school followed by the 

hotel and 16-story office building, while the greatest reductions are realized by the 

restaurant followed by the 3- and 8-story office buildings. 

The occupant activity is the primary driver of the results for the high school, which is 

heavily occupied during the school year and lightly occupied during the summer months. 

Some of the energy efficiency measures decrease heat gains, which lead to lower cooling 

loads during warmer months and greater heating loads during the colder months. A 

significant portion of the reductions in electricity consumption during these colder 

months is offset by increases in natural gas consumption required to meet the increased 

heating loads. Thus, a greater portion of the high school’s energy use occurs during the 

colder months relative to other building types. The combination of more energy use 

occurring during the colder months and the offsetting increase in natural gas consumption 

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State Comparisons for the Adoption of the Low Energy Case Design 

during those months leads to a smaller overall percentage reduction in energy use for 

high schools. 

One of the reasons that the restaurant realizes the greatest reductions in energy use is that 

the restaurant has the smallest plug and process loads in terms of watts per unit of floor 

area. Since the plug and process load is the only electricity use not impacted by the 

energy efficiency measures adopted in this study, a greater fraction of energy use can be 

decreased for restaurants relative to the other building types. 

For all building types, the percentage changes in energy costs and carbon emissions are 

greater than the percentage changes in energy use. This result is most significant for the 

high school, for which the percentage reduction in energy costs is over twice the 

percentage reduction in energy use. Seven of 11 building types realize reductions in lifecycle costs. The restaurant, 3-story office building, and 8-story office building realize the 

greatest percentage reduction in life-cycle costs. The 16-story office building realizes the 

greatest increase in life-cycle costs. 

Table 18-11 Midwest Region Percentage Change for LEC by Building Type, 

10-Year 

Building Percentage Change 

Type Energy Use Energy Cost Carbon LCC 

APART04 -13.0 -20.4 -21.9 0.0 

APART06 -13.5 -21.8 -23.5 -0.0 

DORMI04 -15.4 -21.7 -23.0 -0.6 

DORMI06 -12.8 -20.7 -22.3 -0.4 

HOTEL15 -11.9 -17.8 -19.0 0.0 

HIGHS02 -7.6 -15.8 -17.6 -1.0 

OFFIC03 -21.4 -24.5 -24.9 -1.5 

OFFIC08 -20.8 -22.6 -22.8 -1.3 

OFFIC16 -13.1 -16.8 -17.4 0.5 

RETAIL1 -18.8 -21.4 -21.8 0.0 

RSTRNT1 -28.7 -34.8 -35.7 -3.4 

Average -16.1 -21.7 -22.7 -0.7 

18.2.4 Region-wide Results by Climate Zone 

Table 18-12 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. 

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State Comparisons for the Adoption of the Low Energy Case Design 

Table 18-12 Average Percentage Change for LEC by Climate Zone
 

Climate Zone Energy Energy Carbon LCC 

Use Cost Emissions 

4A -25.1 -31.1 -33.9 -0.5 

5A -13.5 -20.0 -21.0 -0.7 

6A -15.5 -20.0 -20.7 -0.8 

7 -17.5 -21.6 -22.5 -0.6 

Average -16.1 -21.7 -22.9 -0.7 

Table 18-13 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 16.1 % with Zone 4A realizing 

the greatest reduction (25.1 %) and Zone 5A the smallest (13.5 %). Controlling for state 

energy codes, the warmer the climate the greater the reduction in energy use, which is a 

result of the energy efficiency improvement options considered in the LEC design. Cities 

located in Zone 4A and Zone 5A have an additional option (adding overhangs) that is not 

beneficial in the colder climates because solar heat gains are beneficial in cold climates 

and harmful in warm climates. 

Table 18-13 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 

4A -26.7 -25.1 -15.5 -25.1 

5A -25.2 -13.1 -13.5 

6A -21.9 -20.8 -16.1 -12.6 -15.5 

7 -21.3 -20.1 -11.1 -17.5 

Grand Total -24.5 -22.9 -17.7 -12.9 -16.1 

Table 18-14 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 21.7 % with Zone 4A realizing the greatest average reduction 

in energy costs (31.1 %) and Zone 5A and Zone 6A realizing the smallest reduction 

(20.0 %). Similar to energy use, controlling for state energy codes, cities located in 

warmer climates tend to realize greater reductions in energy costs. 

176
 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

State Comparisons for the Adoption of the Low Energy Case Design 

Table 18-14 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 

4A -32.9 -30.6 -20.4 -31.1 

5A -33.3 -19.5 -20.0 

6A -29.6 -28.5 -17.7 -16.6 -20.0 

7 -28.2 -19.7 -16.8 -21.6 

Grand Total -31.4 -29.5 -18.5 -18.7 -21.7 

Table 18-15 shows the average percentage reduction in energy-related carbon emissions 

for all cities located in a climate zone. Similar to energy use and energy costs, while 

controlling for state energy codes, cities located in 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 18-15 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 

4A -35.9 -34.3 -21.4 -33.9 

5A -36.2 -20.5 -21.0 

6A -30.8 -29.6 -18.4 -17.2 -20.7 

7 -29.5 -20.1 -17.8 -22.5 

Grand Total -33.6 -32.0 -19.1 -19.6 -22.9 

Table 18-16 shows the average percentage change in life-cycle costs for all cities located 

in a climate zone while controlling for state energy codes. There are no distinct trends in 

the percentage change in life-cycle costs across climate zones. 

Table 18-16 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 

4A -0.3 -2.0 -0.7 -0.5 

5A -1.0 -0.7 -0.7 

6A -0.6 -2.7 -0.8 -0.7 -0.8 

7 -0.1 -0.8 -0.9 -0.6 

Grand Total -0.4 -2.4 -0.8 -0.7 -0.7 

177
 
State Comparisons for the Adoption of the Low Energy Case Design 

178
 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Discussion 

19 Discussion 

This study analyzes the impacts of adopting new, more stringent state energy codes for 

58 cities located across the Midwest Census Region. Results are summarized at the 

regional level as well as the state level for all twelve Midwestern states. This section will 

discuss the key findings, limitations of the research, and recommended directions for 

future research. 

19.1 Key Findings 

Four states in the Midwest Census Region have not yet adopted a state energy code for 

commercial buildings: Kansas, Missouri, North Dakota, and South Dakota. For these 

states, adoption of ASHRAE 90.1-2001 and -2004 lead to reductions in energy use, energy 

costs, and energy-related carbon emissions. However, adoption of ASHRAE 90.1-2001 is 

not life-cycle cost-effective in any of the four states because the additional costs from 

implementing the energy efficiency measures overwhelm the future energy cost savings. 

ASHRAE 90.1-2004 is not life-cycle cost-effective to adopt in three of the four states, 

with only South Dakota realizing a reduction in life-cycle costs. Adopting ASHRAE 

90.1-2007 leads to greater reductions in energy use, energy costs, and carbon emissions 

than ASHRAE 90.1-2001 or -2004, and is life-cycle cost-effective to adopt in three of the 

four states (Kansas is the exception). 

Minnesota is the only state in the Midwest Census Region that has adopted ASHRAE 

90.1-2004 as its state energy code for commercial buildings. Minnesota would realize 

reductions in energy use, energy costs, energy-related carbon emissions, and life-cycle 

costs from adopting ASHRAE 90.1-2007. 

The adoption of the LEC design is analyzed for all twelve 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 Midwest 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 (16.1 %), energy costs (21.7 %), and 

carbon emissions (22.7 %), on average, while reducing life-cycle costs (0.7 %), 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 four states with no energy code realize the greatest percentage savings in 

energy use, energy costs, and carbon emissions. However, three of the four states realize 

percentage increases in life-cycle costs and the fourth state realizes a minimal percentage 

179
 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Discussion 

decrease. Meanwhile, the states that have already adopted ASHRAE 90.1-2007 realize 

reductions in life-cycle costs. 

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

period length increases from 5 years to 20 years, the number of building types that are 

cost-effective increases from 7 to all 11. The retail store is the only building type that is 

not cost-effective for all study periods longer than 10 years, and is cost-effective for all 

study period lengths of 20 years or greater. 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. There are no distinct trends in life-cycle costs associated with climate zones. 

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 

realize the smallest reductions while restaurants and 3- and 8-story office buildings 

realize the greatest reductions in energy use and energy costs. The reduction in carbon 

emissions is not perfectly correlated with reductions in energy use because along with the 

reduction in energy use, there is a change in the fuel source mix. The greatest percentage 

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

buildings while the smallest percentage reductions are 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 Illinois 

than in Iowa the amount of newly constructed floor area for 2003 to 2007 was almost five 

times greater in Illinois. 

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

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

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, ranging from 404 kWh/m2 

(128 kBtu/ft2) to 456 kWh/m2 (145 kBtu/ft2), followed by the state that has adopted 

ASHRAE 90.1-2004 and realizes reductions of 351 kWh/m2 (111 kBtu/ft2). The states that 

have adopted ASHRAE 90.1-2007 realize reductions ranging from 168 kWh/m2 

180
 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Discussion 

(53 kBtu/ft2) to 206 kWh/m2 (65 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 emission rates per unit of electricity generated tend to realize 

greater reductions in emissions per unit of energy consumption reduced. The greater the 

fraction of the total reduction in energy use that is from electricity consumption, the 

greater the reduction in both energy costs and carbon emissions per unit of energy 

consumption reduced. 

19.2 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 12 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 38 states will allow for estimation of nationwide 

impacts. Also, 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. 

Additional data are needed to refine and expand the BIRDS database. First, the study uses 

simple statewide 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 

181
 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Discussion 

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 Midwest 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 

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 

182
 
 

 

Discussion 

software tool in development will provide the results of this more comprehensive 

sustainability assessment alongside the results summarized in this report. 

183
 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

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/. 

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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. 

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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. 

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187
 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

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 

188
 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Building and Energy Characteristics 

Table A-2 New Commercial Building Construction Floor Area for 2003 through 

2007 by State and Building Type 

State 

Building Construction Floor Area in 1000 m2 (1,000 ft2

) 

ApartmentHealthcare

Hotel

Office

Public

Assembly

657 

(7069) 

Restaurant

Retail

School

Warehouse

No

Prototype

1062 

(11 426) 

Total 

IA 143 

(1542) 

639 

(6875) 

427 

(4598) 

999 

(10 749) 

74 (796) 1350 

(14 534) 

1262 

(13 586) 

621 

(6688) 

7234 

(77 863) 

IL 7303 

(78 609) 

1765 

(18 998) 

1304 

(14 037) 

2930 

(31 542) 

1714 

(18 451) 

232 

(2497) 

5660 

(60 928) 

3083 

(33 180) 

6473 

(69 674) 

4179 

(44 977) 

34 643 

(372 893) 

IN 360 

(3875) 

1728 

(18 600) 

856 

(9210) 

1746 

(18 791) 

1323 

(14 242) 

255 

(2747) 

3302 

(35 539) 

2558 

(27 535) 

3771 

(40 591) 

2415 

(25 992) 

18 313 

(197 123) 

KS 98 (1057) 533 

(5734) 

353 

(3795) 

877 

(9442) 

295 

(3178) 

97 

(1039) 

1122 

(12 076) 

826 

(8892) 

513 

(5521) 

670 

(7216) 

5384 

(57 950) 

MI 446 

(4800) 

1797 

(19 346) 

713 

(7671) 

1696 

(18 251) 

1359 

(14 629) 

200 

(2153) 

3245 

(34 934) 

2058 

(22 151) 

864 

(9305) 

2442 

(26 283) 

14 820 

(159 523) 

MN 1437 

(15 465) 

1018 

(10 954) 

473 

(5093) 

1633 

(17 575) 

527 

(5673) 

102 

(1098) 

2135 

(22 985) 

1175 

(12643) 

803 

(8643) 

2342 

(25 212) 

11 645 

(125 342) 

MO 875 

(9420) 

940 

(10 121) 

881 

(9483) 

1226 

(13 197) 

780 

(8395) 

158 

(1705) 

2513 

(27 054) 

1626 

(17 497) 

819 

(8818) 

1972 

(21 226) 

11 791 

(126 915) 

ND 7 (76) 118 

(1265) 

91 (982) 138 

(1490) 

113 

(1221) 

14 (155) 331 

(3567) 

174 

(1871) 

57 (617) 100 

(1077) 

1145 

(12 320) 

NE 147 

(1586) 

453 

(4880) 

303 

(3263) 

631 

(6790) 

331 

(3562) 

54 (577) 1149 

(12 369) 

514 

(5533) 

340 

(3660) 

676 

(7279) 

4599 

(49 498) 

OH 635 

(6832) 

2452 

(26 393) 

925 

(9959) 

2674 

(28 780) 

1266 

(13 630) 

372 

(4004) 

5132 

(55 245) 

4452 

(47 919) 

3382 

(36 400) 

3243 

(34 909) 

24 533 

(264 071) 

SD 13 (142) 119 

(1285) 

86 (922) 257 

(2767) 

126 

(1354) 

13 (138) 341 

(3668) 

268 

(2884) 

88 (950) 205 

(2202) 

1515 

(16 312) 

WI 906 

(9754) 

1519 

(16 350) 

583 

(6273) 

1556 

(16 751) 

746 

(8030) 

137 

(1474) 

2489 

(26 793) 

1129 

(12 148) 

882 

(9497) 

1981 

(21 325) 

11 928 

(128 395) 

Total 12 371 

(133 158) 

13 081 

(140 801) 

6994 

(75 286) 

16 363 

(176 125) 

9238 

(99 434) 

1708 

(18 383) 

28 771 

(309 692) 

19 123 

(205 839) 

18 614 

(200 364) 

21 286 

(229 124) 

147 549 

(1 588 205) 

189
 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

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 

IA 2.0 % 8.8 % 5.9 % 13.8 % 9.1 % 1.0 % 18.7 % 17.4 % 8.6 % 14.7 % 100.0 % 58.8 % 

IL 21.1 % 5.1 % 3.8 % 8.5 % 4.9 % 0.7 % 16.3 % 8.9 % 18.7 % 12.1 % 100.0 % 59.2 % 

IN 2.0 % 9.4 % 4.7 % 9.5 % 7.2 % 1.4 % 18.0 % 14.0 % 20.6 % 13.2 % 100.0 % 49.6 % 

KS 1.8 % 9.9 % 6.5 % 16.3 % 5.5 % 1.8 % 20.8 % 15.3 % 9.5 % 12.5 % 100.0 % 62.6 % 

MI 3.0 % 12.1 % 4.8 % 11.4 % 9.2 % 1.3 % 21.9 % 13.9 % 5.8 % 16.5 % 100.0 % 56.4 % 

MN 12.3 % 8.7 % 4.1 % 14.0 % 4.5 % 0.9 % 18.3 % 10.1 % 6.9 % 20.1 % 100.0 % 59.7 % 

MO 7.4 % 8.0 % 7.5 % 10.4 % 6.6 % 1.3 % 21.3 % 13.8 % 6.9 % 16.7 % 100.0 % 61.7 % 

ND 0.6 % 10.3 % 8.0 % 12.1 % 9.9 % 1.3 % 29.0 % 15.2 % 5.0 % 8.7 % 100.0 % 66.1 % 

NE 3.2 % 9.9 % 6.6 % 13.7 % 7.2 % 1.2 % 25.0 % 11.2 % 7.4 % 14.7 % 100.0 % 60.8 % 

OH 2.6 % 10.0 % 3.8 % 10.9 % 5.2 % 1.5 % 20.9 % 18.1 % 13.8 % 13.2 % 100.0 % 57.8 % 

SD 0.9 % 7.9 % 5.7 % 17.0 % 8.3 % 0.8 % 22.5 % 17.7 % 5.8 % 13.5 % 100.0 % 64.5 % 

WI 7.6 % 12.7 % 4.9 % 13.0 % 6.3 % 1.1 % 20.9 % 9.5 % 7.4 % 16.6 % 100.0 % 57.0 % 

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

State CO2 CH4 N2O 

(t/GWh) (t/GWh) (t/GWh) 

IA 851.1 40.4 0.2 

IL 948.3 44.4 0.2 

IN 835.7 38.9 0.2 

KS 926.0 44.8 0.3 

MI 861.4 46.8 0.6 

MN 851.1 40.4 0.2 

MO 939.4 44.6 0.2 

ND 851.1 40.4 0.2 

NE 851.1 40.4 0.2 

OH 835.7 38.9 0.2 

SD 851.1 40.4 0.2 

WI 860.7 44.1 0.4 

190
 
Building and Energy Characteristics 

191
 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

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 

IA -9.8 -15.8 -16.8 0.5 

IL -9.4 -17.1 -17.1 0.3 

IN -10.1 -16.0 -17.1 0.6 

KS -24.9 -35.3 -39.1 -1.6 

MI -8.5 -15.2 -16.3 0.4 

MN -13.8 -18.0 -18.6 0.2 

MO -25.4 -33.3 -38.6 -1.0 

ND -17.5 -30.8 -33.4 -1.0 

NE -9.8 -16.3 -17.2 0.7 

OH -9.6 -16.0 -17.1 0.5 

SD -21.2 -34.1 -35.9 -1.7 

WI -9.5 -15.9 -16.4 0.4 

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 

IA -10.6 -17.6 -18.7 0.5 

IL -10.5 -20.0 -20.1 0.1 

IN -11.3 -18.7 -20.1 0.5 

KS -25.9 -37.4 -41.4 -1.8 

MI -8.9 -16.7 -17.9 0.3 

MN -13.0 -17.3 -17.9 0.4 

MO -26.5 -35.2 -40.9 -1.1 

ND -17.2 -30.5 -33.1 -0.9 

NE -11.2 -19.5 -20.5 0.6 

OH -10.6 -18.5 -19.9 0.4 

SD -20.6 -33.5 -35.4 -1.5 

WI -9.3 -15.5 -16.0 0.5 

192
 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

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 

IA -11.7 -16.7 -17.5 -0.2 

IL -11.1 -17.8 -17.8 -0.3 

IN -11.8 -16.9 -17.9 -0.4 

KS -27.6 -37.1 -40.4 0.3 

MI -10.7 -16.5 -17.4 -1.2 

MN -19.0 -20.7 -20.9 -1.5 

MO -27.4 -35.0 -39.8 0.2 

ND -21.6 -33.7 -36.0 0.3 

NE -11.7 -17.2 -17.9 -0.2 

OH -11.2 -16.9 -17.8 -1.2 

SD -24.0 -35.7 -37.3 -1.4 

WI -12.0 -17.0 -17.4 -0.8 

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

State Percentage Change 

Energy Use Energy Cost Carbon LCC 

IA -10.0 -16.4 -17.4 0.2 

IL -10.3 -19.4 -19.4 -0.2 

IN -11.0 -18.1 -19.4 0.2 

KS -24.8 -36.3 -40.4 -2.6 

MI -8.5 -15.9 -17.1 0.1 

MN -11.3 -15.2 -15.7 0.2 

MO -26.0 -34.9 -40.6 -1.9 

ND -16.6 -28.8 -31.2 -1.6 

NE -10.9 -18.8 -19.8 0.3 

OH -10.3 -17.9 -19.2 0.1 

SD -17.3 -30.6 -32.5 -2.0 

WI -8.2 -13.7 -14.2 0.2 

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 

IA -11.0 -15.3 -16.0 0.5 

IL -11.8 -19.2 -19.2 0.2 

IN -12.3 -18.1 -19.2 0.5 

KS -19.7 -29.4 -32.9 -1.5 

MI -10.1 -15.5 -16.4 0.2 

MN -6.8 -6.8 -6.8 0.9 

MO -19.8 -27.5 -32.6 -0.9 

ND -10.0 -20.8 -22.8 -1.1 

NE -12.7 -18.9 -19.7 0.6 

OH -11.8 -18.1 -19.2 0.4 

SD -11.8 -21.8 -23.2 -1.3 

WI -8.9 -11.2 -11.4 0.4 

193
 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Additional BIRDS Database Results 

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 

IA -6.1 -13.8 -15.2 -0.8 

IL -5.6 -16.4 -16.5 -1.1 

IN -6.4 -14.8 -16.6 -0.8 

KS -13.7 -23.4 -27.7 -1.5 

MI -4.6 -12.7 -14.2 -0.8 

MN -9.2 -14.1 -14.9 -1.1 

MO -14.3 -21.7 -27.7 -1.4 

ND -11.1 -18.9 -20.8 -0.9 

NE -5.8 -15.0 -16.4 -0.6 

OH -5.6 -14.2 -15.8 -0.8 

SD -10.9 -20.0 -21.7 -1.8 

WI -5.9 -12.7 -13.4 -1.1 

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 

IA -17.3 -19.6 -19.8 -1.5 

IL -17.8 -21.0 -21.0 -2.2 

IN -18.5 -20.8 -21.1 -2.0 

KS -32.5 -33.1 -33.3 0.3 

MI -16.7 -19.6 -19.8 -2.2 

MN -21.4 -19.8 -19.6 -1.3 

MO -32.3 -32.5 -32.6 0.4 

ND -26.0 -28.1 -28.4 1.3 

NE -18.5 -21.2 -21.5 -2.2 

OH -17.9 -20.6 -20.9 -2.2 

SD -26.8 -28.4 -28.6 -0.5 

WI -16.4 -18.0 -18.1 -1.2 

194
 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Additional BIRDS Database Results 

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 

IA -13.0 -16.2 -16.6 0.6 

IL -13.9 -19.8 -19.8 0.2 

IN -15.0 -19.7 -20.4 0.6 

KS -17.1 -21.6 -23.1 0.3 

MI -12.6 -16.9 -17.5 0.2 

MN -8.7 -7.8 -7.7 1.0 

MO -16.3 -20.0 -22.2 0.9 

ND -9.9 -13.5 -14.1 0.4 

NE -15.2 -20.2 -20.7 0.8 

OH -14.4 -19.5 -20.2 0.5 

SD -10.1 -13.2 -13.6 0.2 

WI -10.9 -11.9 -12.0 0.3 

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 

IA -14.3 -17.2 -17.6 0.6 

IL -12.5 -16.9 -16.9 -0.4 

IN -13.5 -16.8 -17.4 0.5 

KS -30.6 -33.9 -35.1 1.0 

MI -12.6 -16.0 -16.4 -0.3 

MN -27.3 -23.9 -23.5 -0.8 

MO -31.3 -33.5 -34.8 1.7 

ND -31.8 -33.4 -33.7 0.6 

NE -12.5 -16.8 -17.2 0.8 

OH -12.5 -16.1 -16.6 -0.5 

SD -29.9 -33.5 -34.0 -0.9 

WI -15.9 -18.0 -18.1 -1.1 

195
 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Additional BIRDS Database Results 

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

Period 

State Percentage Change 

Energy Use Energy Cost Carbon LCC 

IA -23.7 -30.3 -31.2 -4.4 

IL -23.3 -32.6 -32.6 -4.5 

IN -24.8 -31.9 -33.1 -4.3 

KS -40.8 -46.4 -48.3 -1.2 

MI -22.1 -30.3 -31.4 -3.0 

MN -37.9 -36.3 -36.1 -5.0 

MO -39.1 -43.9 -46.8 -3.3 

ND -41.8 -44.2 -44.6 -0.2 

NE -24.2 -32.6 -33.5 -3.9 

OH -23.3 -31.4 -32.6 -3.4 

SD -39.0 -43.6 -44.2 -3.0 

WI -23.6 -28.7 -29.1 -3.3 

196