NIST Technical Note 1880

Building Industry Reporting and 

Design for Sustainability (BIRDS) 

Tutorial for New Residential Database

Joshua Kneifel

Priya Lavappa

This publication is available free of charge from:

http://dx.doi.org/10.6028/NIST.TN.1880

 

NIST Technical Note 1880

Building Industry Reporting and 

Design for Sustainability (BIRDS) 

Tutorial for New Residential Database

Joshua Kneifel

Priya Lavappa

Applied Economics Office

Engineering Laboratory

This publication is available free of charge from:

http://dx.doi.org/10.6028/NIST.TN.1880

May 2015

U.S. Department of Commerce 

Penny Pritzker, Secretary

National Institute of Standards and Technology 

Willie May, Acting Under Secretary of Commerce for Standards and Technology and Acting Director
ii

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 Technical Note 1880

Natl. Inst. Stand. Technol. Tech. Note 1880, 25 pages (May 2015) 

http://dx.doi.org/10.6028/NIST.TN.1880

CODEN: NTNOEF
iii

Abstract

Building stakeholders need practical metrics, data, and tools to support decisions related 

to sustainable building designs, technologies, standards, and codes. The Engineering 

Laboratory of the National Institute of Standards and Technology (NIST) has addressed 

this high priority national need by extending its metrics and tools for sustainable building 

products, known as Building for Environmental and Economic Sustainability (BEES), to 

whole buildings. Whole building sustainability metrics have been developed based on 

innovative extensions to life-cycle assessment (LCA) and life-cycle costing (LCC) 

approaches involving whole building energy simulations. The measurement system 

evaluates the sustainability of both the materials and the energy used by standardized 

buildings over time. It assesses the “carbon footprint” of buildings as well as 11 other 

environmental performance metrics, and integrates economic performance metrics to 

yield science-based measures of the business case for investment choices in highperformance green buildings.

Building Industry Reporting and Design for Sustainability (BIRDS) applies the new 

sustainability measurement system to an extensive whole building performance database 

NIST has compiled for this purpose. The BIRDS new residential building database 

includes energy, environmental, and cost measurements, covering 10 single-family 

dwellings (5 one-story and 5 two-story of varying conditioned floor area) in 228 cities 

across all U.S. states for a total of 9120 new residential building combinations for study 

period lengths ranging from 1 year to 40 years. The sustainability performance of 

buildings designed to meet current state energy codes can be compared to their 

performance when meeting three alternative building energy standard editions to 

determine the impact of energy efficiency on sustainability performance. The impact of 

the building location and the investor’s time horizon on sustainability performance can 

also be measured.

This document is a tutorial to assist BIRDS users in understanding and using the BIRDS 

New Residential Buildings Database Web Interface, including detailed definitions for and 

explanation for the purpose of each input and output option.

Keywords

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

efficiency; residential buildings
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v

Preface

This study was conducted by the Applied Economics Office (AEO) in the Engineering 

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

BIRDS new residential database web interface is designed to assess the sustainability 

performance (energy, environmental, and cost impacts) of the adoption of new residential 

building designs. The intended audience is users of BIRDS, such as researchers and 

decision makers in the residential building sector, and others interested in building 

sustainability.

Disclaimers

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 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 authors wish to thank all those who contributed ideas and suggestions for this report. 

They include Dr. Eric O’Rear and Dr. Robert Chapman of EL’s Applied Economics 

Office, Dr. Dustin Poppendieck of EL’s Energy and Environment Division, and Dr. 

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

the Industrial Ecology Research Services team of Shivira Tomar, Christine Chen, and 

Matthew Leighton for superb technical support in developing whole building life cycle 

assessments for BIRDS. Thanks to Mr. Brian Presser and Mr. Samuel Sharpe for 

assisting in developing the energy simulations and generating the new residential 

sustainability database. Thanks to Mr. Tarang Hirani for assisting in the development of 

BIRDS v2.0 web interface. Finally, the many Beta testers of BIRDS v2.0 deserve special 

thanks for contributing suggestions leading to substantial improvements in the tool.

Author Information

Joshua 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

Priya Lavappa

Computer Specialist

National Institute of Standards and Technology

Engineering Laboratory

100 Bureau Drive, Mailstop 8603

Gaithersburg, MD 20899 8603

Tel.: 301-975-4522

Email: priya.lavappa@nist.gov
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Contents

Abstract.............................................................................................................................iii

Preface................................................................................................................................ v

Acknowledgements ......................................................................................................... vii

Author Information ........................................................................................................ vii

List of Acronyms............................................................................................................ xiii

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

2 BIRDS New Residential Buildings Database Tutorial .......................................... 3

2.1 Step 1: Selecting Your Building........................................................................... 6

2.2 Step 2: Selecting Your Comparisons ................................................................... 8

2.3 Step 3: Selecting Environmental Weighting Preferences .................................. 12

2.4 Step 4: Viewing Results..................................................................................... 15

3 Summary.................................................................................................................. 23

References........................................................................................................................ 25
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List of Figures

Figure 1-1 BIRDS Sustainability Framework.................................................................... 2

Figure 2-1 BIRDS Main Webpage - Introduction ............................................................. 3

Figure 2-2 BIRDS Main Webpage – Related Links.......................................................... 4

Figure 2-3 BIRDS Main Webpage – Database Links........................................................ 5

Figure 2-4 BIRDS Main Webpage – Start Analysis.......................................................... 5

Figure 2-5 BIRDS New Residential Interface – Initial View............................................ 6

Figure 2-6 Selecting Building Type................................................................................... 7

Figure 2-7 Building Prototype Details............................................................................... 8

Figure 2-8 Selecting Baseline Values................................................................................ 9

Figure 2-9 Selecting Alternative Locations, Energy Standard Editions, and Study Periods

........................................................................................................................................... 11

Figure 2-10 Selecting Environmental Weighting Preferences......................................... 13

Figure 2-11 Selecting Environmental Weighting Approaches........................................ 14

Figure 2-12 Selecting Chart Options ............................................................................... 15

Figure 2-13 Life-Cycle Cost Graph by Location for Baseline Assumptions................... 17

Figure 2-14 Life-Cycle Cost Graph by Study Period for Baseline Assumptions............ 18

Figure 2-15 Annual Operating Energy Per ft2by Code Edition for Baseline Assumptions

........................................................................................................................................... 19

Figure 2-16 Change in Life-Cycle Costs by Code Edition for Baseline Assumptions.... 20

Figure 2-17 Change in Environmental Impact Score by Code Edition – for Baseline 

Assumptions...................................................................................................................... 21

Figure 2-18 Change in Global Warming Potential by Code Edition – for Baseline 

Assumptions...................................................................................................................... 22
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List of Acronyms

Acronym Definition

AEO Applied Economics Office

BEES Building for Environmental and Economic Sustainability

BIRDS Building Industry Reporting and Design for Sustainability

CO2e cardon dioxide equivalent

EIS Environmental Impact Score

EL Engineering Laboratory

EPA Environmental Protection Agency

FAQ Frequently Asked Questions

HVAC Heating, Ventilation, and Air Conditioning

IECC International Energy Conservation Code

I-O input-output

ISO International Organization for Standardization

LCA Life-Cycle Assessment

LCC Life-Cycle Cost

NIST National Institute of Standards and Technology

NZERTF Net-Zero Energy Residential Test Facility

SFD Single-Family Detached
xiv
1

1 Introduction

A wave of interest in sustainability gathered momentum in 1992 with the Rio Earth Summit, 

during which the international community agreed upon a definition of sustainability in the 

Bruntland report: “meeting the needs of the present generation without compromising the ability 

of future generations to meet their own needs” (Brundtland, 1987). In the context of sustainable 

development, needs can be thought to include the often-conflicting goals of environmental 

quality, economic well-being, and social justice. While the intent of the 1992 summit was to 

initiate environmental and social progress, it seemed to have instead brought about greater debate 

over the inherent conflict between sustainability and economic development.

This conflict is particularly apparent within the construction industry. Frequently, 

well-intentioned green development plans are not executed for economic reasons, and economic 

development plans fail to materialize over concerns for the environment and public health. Thus, 

an integrated approach to sustainable construction—one that simultaneously considers both 

environmental and economic performance—lies at the heart of reconciling the conflict. For this 

reason, building stakeholders need practical metrics, data, and tools to support decisions related 

to sustainable building designs, technologies, standards, and codes that consider both the 

environmental and economic dimensions of sustainability. 

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

has addressed this high priority national need by extending its metrics and tools for sustainable 

building products, known as Building for Environmental and Economic Sustainability (BEES)

(BEES 2010), to whole buildings. Whole building sustainability metrics have been developed 

based on innovative extensions to life-cycle assessment (LCA) and life-cycle costing (LCC) 

approaches involving whole building energy simulations. The measurement system evaluates the 

sustainability of both the construction materials and the energy used by a building over time. It 

assesses the “carbon footprint” of buildings as well as 11 other environmental performance 

metrics, and integrates economic performance metrics to yield science-based measures of the 

business case for investment choices in high-performance green buildings. The BEES approach

does not consider the social dimension of sustainability due to the current lack of rigorous 

measurement methods.

The approach developed for BEES has now been applied at the whole building level to address 

building sustainability measurement in an integrated manner that considers complex interactions 

among building materials, energy technologies, and systems across dimensions of performance, 

scale, and time. Building Industry Reporting and Design for Sustainability (BIRDS) applies the 

new sustainability measurement system to an extensive whole building performance database 

NIST has compiled for this purpose (BIRDS 2014). The energy, environment, and cost data in 

BIRDS measure building operating energy use through detailed energy simulations, building 

materials use through innovative life-cycle material inventories, and building costs over time. 

BIRDS v1.0 included energy, environmental, and cost measurements for 11 building prototypes 
2

in 228 cities for a total of 12 540 new commercial and non low-rise residential building designs 

across all U.S. states for 9 study period lengths. All the variables shown in Figure 1-1 are 

accounted for in the BIRDS database. See Lippiatt et al. (2013) for additional details.

Environmental Energy Simulation

Life Cycle Assessment

Economic

Life Cycle Costing

Local Prices

•Construction

•Current Fuel Prices

•Fuel Price Projections

Function

Design

Size

Location

Energy Technologies

•HVAC

•Envelope

•Efficiency

Maintenance, Repair &

Replacement Schedules

Building Service Life

Energy Code

Climate

Building Type

•Low-Rise Residential

Sustainability

Performance

Economic

Performance

Environmental

Performance Energy

Performance

Materials Acquisition

Manufacturing

Transportation

Installation/Use

Service Life

End of Life

BIRDS Database

Fuel Type

•Heating

•Cooling

Building Specifications

Global Warming

Resource Use

Human Health

Water Pollution

Air Pollution

Figure 1-1 BIRDS Sustainability Framework

Similarly, the new residential building database incorporated into BIRDS v2.0 includes energy, 

environmental, and cost measurements covering 10 single family dwellings (5 one-story and 5 

two-story of varying conditioned floor area) in 228 cities across all U.S. states for a total of 9120 

new buildings for study period length ranging from 1 year to 40 years. The sustainability 

performance of buildings designed to meet current state residential energy codes (based on 

building requirements defined in the International Energy Conservation Code (IECC)) can be 

compared to their performance when built to three alternative building energy standard editions 

to determine the impact of energy efficiency on sustainability performance. The impact of the 

building location and the investor’s time horizon on sustainability performance can also be 

analyzed. This document displays the capabilities of the BIRDS new residential buildings 

database through a detailed tutorial. See Kneifel et al. (2015) for additional details related to the 

underlying assumptions, data sources, and approaches implemented to develop the BIRDS new 

residential database.
3

2 BIRDS New Residential Buildings Database Tutorial

A user begins on the BIRDS main webpage, which is a “one-stop shop” for information related 

to BIRDS. In the center of the webpage, there is an introduction to the purpose and capabilities 

of the BIRDS databases (highlighted in Figure 2-1).

Figure 2-1 BIRDS Main Webpage - Introduction
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On the left hand side of the main page, a user can access information related to BIRDS, 

including recent news, related publications, and other related links (highlighted in Figure 2-2). 

Recent news will include news articles, press releases, and announcements related to BIRDS. 

The most recent and/or most downloaded BIRDS-related publications are shown, which a link to 

the NIST publication database to allow for a complete search of BIRDS publications. Related 

links include BIRDS’s “sister software” – BEES – that allows for comparison of individual 

building products and the NIST Net Zero Energy Residential Test Facility (NZERTF) main page 

as well as access to the Applied Economics Office and the Engineering Laboratory at NIST.

If the user is interested in additional information not available from the BIRDS main page or 

have comments to improve BIRDS, a user can contact NIST at either birds@nist.gov or 

joshua.kneifel@nist.gov.

Figure 2-2 BIRDS Main Webpage – Related Links
5

Above the introduction are links directing you to each of the BIRDS databases (highlighted in 

Figure 2-3). The Residential Buildings and Commercial Buildings “Start Analysis >>” links 

direct you to the new residential database and new commercial buildings database, respectively. 

Each database allows for sustainability comparison across different building designs based on 

building energy code/standard. The current Low Energy Residential “Learn More >>” link 

directs the user to the NIST NZERTF webpage, where the user can access specifications, 

performance data, publications, and other information about the NZERTF. Once the Low Energy 

Residential database web interface is released (planned for September 2016) The link will 

eventually be changed to the “Start Analysis >>” link directing the user to the low-energy 

residential database, which will allow a user to compare the sustainability performance of 

incremental changes in energy efficiency measures adopted in a single-family dwelling based on 

the NZERTF ranging from 2003 IECC to the NZERTF design. 

Figure 2-3 BIRDS Main Webpage – Database Links

For this tutorial, the user selects the Residential Buildings “Start Analysis >>” link and is 

directed to the BIRDS New Residential database web interface (highlighted in Figure 2-4). 

Figure 2-4 BIRDS Main Webpage – Start Analysis
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The New Residential web interface defaults the user to Step 1 as shown in Figure 2-5. There are 

four steps in completing and viewing sustainability comparisons:

1. Select the building prototype to evaluate. 

2. Select baseline values and alternatives for comparison (location, standard edition, and 

study period).

3. Select baseline and alternative weighting preferences for environmental performance.

4. View results graph and data.

At any step in the process, the user can access the BIRDS Home webpage, BIRDS New 

Residential database documentation, this tutorial, and the BIRDS FAQ at the top-right corner of 

the page as shown in Figure 2-5.

Figure 2-5 BIRDS New Residential Interface – Initial View

The remainder of this tutorial will walk the user through a detailed example and the resulting 

comparisons available to the user. Note that there are a variety of values that the user must select 

in order to view results, but BIRDS v2.0 includes further information (by clicking on the 

information icons) and default values (where determined necessary) to assist a user in making 

those selections.

2.1 Step 1: Selecting Your Building

The user completes “Step 1: Select Your Building” by selecting the building characteristics from 

the drop-down menus as shown in Figure 2-6 that best match to the building the user wants to 

analyze. The selections are sequential, and must be selected from left to right. The user first 

selects the Building Type, which currently only allows for the selection of Single Family 
7

Detached dwellings (i.e. houses). Second, the user selects the Number of Stories, which 

currently includes 1-story or 2-stories.1 Finally, the user selects the Size (ft2). There are five 

different “sizes” for both 1-story and 2-story single-family detached dwellings. Note that future 

versions of the new residential database could include low-rise multifamily dwellings (apartment 

buildings and condominiums) and/or semi-detached dwellings (townhouses).

Figure 2-6 Selecting Building Type

For this tutorial, assume that the user is considering building a 1-story, 149 m2(1600 ft2) house 

as shown in Figure 2-7. Note that by clicking on the information icon (circled in red) the building 

details are expanded to be viewed by the user, which includes additional information such as 

orientation, floor height, percent fenestration, and heating and cooling equipment types. Since 

this is the first time an information icon appears, a text box has been included to alert the user of 

the information icon buttons. Note that future versions of the database may include additional 

options for the user (e.g. fuel type for heating). After selecting the building type, stories, and size

the user wants to analyze, it is time to select what the user wants to compare.

 

1 No 3-story houses are considered because they account for less than 4 % of all detached housing in any Census 

Division.
8

Figure 2-7 Building Prototype Details

2.2 Step 2: Selecting Your Comparisons

Clicking on the “Step 2: Select Your Comparisons” tab displays dropdown menus for the 

preferred Baseline Values for the building’s State, City, Standard Edition, and Study Period as 

shown in Figure 2-8 (highlighted in red). These are the baseline values that will be used for all 

comparisons, and must be selected before moving on. Note that all baseline values must be 

defined or an error will occur, and you will be diverted back to this step to select missing values. 

The information icon next to “Baseline Values” includes definitions of each baseline value that 

must be selected to assist a user that is not familiar with these factors. There is an additional 

information icon next to “Select Standard Edition” that includes a map with current state 

residential energy codes (as of July 2014).
9

Figure 2-8 Selecting Baseline Values

For this tutorial, assume that the user is building the house in Boulder, Colorado.2 Based on the 

map in the information icon, Colorado currently requires new residential construction to meet 

 

2 Results are based on state-level average electricity prices, city-specific weather data, building energy code-climate 

zone specific requirements, and local construction costs. See Kneifel et al. (2015) for additional details.
10

2003 IECC requirements. The user expects to live in the home for 5 years before reselling the 

house. Based on this information, the baseline values selected are the following as shown in 

Figure 2-9: Baseline Location is Boulder, Colorado, Baseline Code Edition is 2003 IECC, and 

Study Period is 5 years.

Once the baseline values have been defined the user can select one or more alternatives to 

compare to their baseline across the three factors. The user can click on the information icon to 

obtain additional information on each set of alternative values.

Under [1.] in Figure 2-9 (in red) the user can select alternative locations for comparison to the 

baseline location assuming the same code edition (2003 IECC) and study period (5 years). 

Assume the user wants to compare across locations is to see how much variation can occur in the 

results if the same house is constructed in different locations in a state to the same underlying 

code edition. In order to select alternative locations, the user must first select (by clicking on) a 

state from the scroll box. Then a checkbox list of available cities in that state will appear. When a 

user clicks the checkbox, the city/state combination will be added to the list to the right. Up to 5 

alternative locations can be selected for comparison to the baseline location, as shown in Figure 

2-9. In this example, the five remaining available cities in Colorado have been selected for 

comparison (Alamosa, Colorado Springs, Eagle, Grand Junction, and Pueblo). Boulder has been 

automatically removed from the alternative location list because it is the baseline location.

Under [2.] in Figure 2-9 (in orange) the user can select up to three alternative energy code

editions from the checkbox list at the top right, which include 2003 IECC, 2006 IECC, 2009 

IECC, and 2012 IECC. Since 2003 IECC is the selected baseline code edition, it is not an option 

for selection as an alternative. For this tutorial, assume that the user wants to consider 

constructing the house to each of the newer editions of IECC to determine if newer editions lead 

to energy savings, and if so, the cost-implications from constructing to the more energy efficient 

designs.
11

Figure 2-9 Selecting Alternative Locations, Energy Standard Editions, and Study Periods

Under [3.] in Figure 2-9 (in purple) the user can select up to 39 alternative study periods in the 

checkbox list at the bottom right, which range from 1 year to 40 years and includes a “Select 

All” button for users that want to quickly and easily consider all study periods. For this tutorial, 

assume the user wants to consider longer study periods, in 5-year increments (10-years, 15-years, 
12

20-years, 25-years, 30-years, 35-years, and 40-years) to see how the results will change if the 

house is owned for longer timeframes. The 5-year study period is the baseline and cannot be 

selected as an alternative. Once the user has defined the baseline values and the alternative 

values for comparison, the user needs to move onto Step 3 to define environmental preferences.

2.3 Step 3: Selecting Environmental Weighting Preferences

Clicking on the “Step 3: Select Your Environmental Preferences” displays an introductory 

paragraph. For further explanation of each of the environmental impact categories, click on the 

information icon in the text. The user must start by selecting their Baseline Environmental 

Weight Approach from the dropdown menu, which includes 5 options (four pre-defined and one 

user-defined) as shown in Figure 2-10 (in red). The weights for each of the four pre-defined 

approaches can be viewed by the user in the table on the right-hand side (in purple).

Explanations of the source of the BEES Stakeholder Panel and EPA Advisory Board weighting 

approaches can be found under the information icon. For this tutorial, assume that the user 

selects the BEES Stakeholder Panel as the baseline. Below the Baseline selection are check 

boxes for the alternative weighting approaches that will be available for comparison (in orange).
13

Figure 2-10 Selecting Environmental Weighting Preferences

If the user does not want to use any of the pre-defined weighting approaches, the user is given 

flexibility to create a custom weighting approach by checking the “Create Weighting Approach”

checkbox, which can be used as the baseline or as an alternative weighting approach. As shown 

in Figure 2-11, checking the “My Weights” check box brings up a list of the 12 environmental 

impact categories. Each category must be given a weight between 0 and 100, with the sum of all 

12 weights adding up to 100. Assume the user wants to place equal weight (25 %) to only four 
14

categories (global warming, acidification (i.e. acid rain), ozone depletion, and water 

consumption) and ignore other environmental impacts. Once a custom weighting approach is 

defined it will become a selection available in the Baseline Weighting Approach dropdown and 

as a checkbox in the Alternative Weighting Approach checkbox list. Assume that the user selects 

all available alternative weighting approaches, including the custom weighting approach. At this 

point, all the necessary user inputs have been defined and the user can now look at the results.

Figure 2-11 Selecting Environmental Weighting Approaches
15

2.4 Step 4: Viewing Results

Clicking on the “Step 4: View Results” tab will display the “Select Chart Options” section. Three 

different chart types are available in the application: Life-Cycle Cost, Operating Energy, or 

Environmental Impact Score (EIS). As shown in Figure 2-12, the user must first select the “Chart 

Type” from the dropdown menu, then the “Baseline” for which the comparison to be made, and 

the “Units” in which the user prefers the results. Note that the units include a per unit of floor 

area impact, which is only reported in square feet within BIRDS and not square meters because 

the tool is designed for use domestically, which predominantly uses I-P units instead of metric 

units. For additional information, a user can click on the information icons. Once the user has 

made these selections, the user presses the “View” button to see the results, at which point the 

graph with corresponding data table will be displayed.

Figure 2-12 Selecting Chart Options
16

Assume that the first comparison the user would like to view is the life-cycle costs of the 

baseline building design and study period across the selected locations. Figure 2-13 shows the 

Life-Cycle Cost results with a graph of the total life-cycle costs per ft2in present value dollars

(PV$) for the 5-year study period for a 1-story, 149 m2(1600 ft2) house built to meet 2003 IECC

across the six locations selected by the user. As can be seen in the graph, total present value (PV) 

life-cycle costs (LCC) per ft2vary from $250.80/m2($23.30/ft2) to over $264.79/ m2($24.60/ft2).

Even within the same state, constructing a house to the same energy standard can lead to 

different costs to the owner because of variations in code requirements by climate zone as well as 

local construction cost differences. The baseline value line, which is included to allow for easy 

comparisons across alternatives, shows that two cities realize lower life-cycle costs (LCCs) and 

three cities realize higher LCCs than Boulder.
17

Figure 2-13 Life-Cycle Cost Graph by Location for Baseline Assumptions

A user can interact with the graph by (1) scrolling over and viewing the value of each data point 

and (2) zooming in and out of a graph to focus on a portion of the data.

The data table displayed below the graph is more comprehensive, and includes all of the 

potential metrics available for comparisons across study periods for the baseline location, which 
18

include total life-cycle costs, change in total life-cycle costs relative to the selected baseline, total 

life-cycle costs per ft2, change in total life-cycle costs from the baseline per ft2, and percentage 

change in life-cycle costs relative to the baseline.

Next, the user decides to see how LCCs change as the study period increases in length. By 

changing the baseline across which to analyze the data from “Locations” to “Study Periods,” 

selecting Present Value $/ft2”and clicking “View,” the user can now see that that LCCs increase 

at a decreasing rate as the study period increases in length (see Figure 2-14). The reason for this 

trend is that the further into the future that costs are realized, the smaller the discounted present 

value of those costs.

Figure 2-14 Life-Cycle Cost Graph by Study Period for Baseline Assumptions
19

Now the user shifts to focusing analysis on changing in the building design for the baseline 

location and study period. Figure 2-15 shows the Operating Energy results in annual energy 

consumption per ft2(in kBtu) across the four standard editions. Energy consumption is relatively 

constant across the baseline code edition (2003 IECC) and 2006 IECC and 2009 IECC, with 

2006 IECC actually slightly increasing consumption and 2009 IECC slightly decreasing 

consumption (within +/- 0.3 kWh/m2(0.1 kBtu/ft2)). The 2006 IECC design could lead to an 

increase in energy consumption because of the change in climate zone characterization between 

2003 IECC and 2006 IECC (there are fewer zones based on different combinations of heating 

degree days and cooling degree days). Constructing to meet the requirements in 2012 IECC leads 

to a 20 % reduction in energy consumption relative to 2003 IECC (48.6 kWh/m2(15.4 kBtu/ft2) 

versus 60.9 kWh/m2(19.3 kBtu/ft2)).

Figure 2-15 Annual Operating Energy Per ft2 by Code Edition for Baseline Assumptions
20

Now the user wants to determine if the energy savings realized by constructing to 2012 IECC is 

cost-effective. By selecting Life-Cycle Cost – Energy Codes – Change in PV$, the user can view 

how LCCs differ across code editions. Figure 2-16 shows that building to meet 2006 IECC leads 

to the greatest reduction in LCCs relative to building to meet 2003 IECC (baseline). However, as 

was shown in Figure 2-15, the 2006 IECC design consumes the most energy. The building 

requirements are more lax for 2006 IECC relative to 2003 IECC, leading to lower first costs that 

outweigh the higher energy costs realized by the design. The 2012 IECC design not only leads to 

the lowest energy consumption, it also leads to LCC savings ($286) relative to the 2003 IECC 

design.

Figure 2-16 Change in Life-Cycle Costs by Code Edition for Baseline Assumptions
21

If the user is interested in seeing how the different building designs impact the life-cycle 

environmental performance of the house, then the user must make an additional selection, the 

environmental impact category, which can be either a single impact category or the weighted 

average impact (Environmental Impact Score – EIS) based on the baseline weighting approach 

(BEES Stakeholder Panel). In this case, assume that the user wants to look at the Environmental 

Impact Score. By selecting Environmental Impact-Energy Standard-All (weighted)-

Environmental Impact Score, the user sees the results in Figure 2-17, which shown that the 2012 

IECC design leads to the greatest reduction in Environmental Impact Score (0.74 or 4.3 %).

Figure 2-17 Change in Environmental Impact Score by Code Edition – for Baseline 

Assumptions
22

The user can also view each individual environmental impact category results. For example, 

Figure 2-18 shows a graph of the total global warming potential impacts in kilograms of CO2e 

emissions. The 2012 IECC design leads to the lowest impact on global warming potential, with a 

reduction of 11 717 kg of CO2e flows relative to the 2003 IECC design.

Figure 2-18 Change in Global Warming Potential by Code Edition – for Baseline 

Assumptions
23

3 Summary

This tutorial guides the user through a detailed example of analysis that can be completed using 

the BIRDS new residential database web interface. The energy, environmental, and economic 

performance of a wood-framed, single-family dwelling was compared across a number of 

factors. The life-cycle costs of the baseline building design (constructed to meet 2003 IECC 

requirements) was compared to the same building design located in 5 other cities across 

Colorado. The life-cycle costs of constructing to the same energy code edition can vary across 

cities within a state. Depending on the location. The life-cycle costs per unit of floor area were 

compared for Boulder as the study period length changed from 5 year to 40 years, showing that 

life-cycle costs increase as the study period length increases. All three areas of performance 

were analyzed for Boulder as the code edition to which the building was constructed changes to 

newer editions of the code. Relative to the baseline code (2003 IECC), the greatest change in 

operating energy consumption occurs from constructing to meet 2012 IECC requirements, which 

also realizes reductions in life-cycle costs, Global Warming Potential (i.e. “carbon”) and the 

Environmental Impact Score.

These are just some of the comparisons the user could make with BIRDS. The associated 

documentation (Kneifel et al. 2015) for the BIRDS new residential database will assist with any 

questions related to the underlying definitions, assumptions, data sources, and methodology. 

Future versions of BIRDS will update current databases with additional energy code editions and 

more features as well as an additional database that will include low-energy residential building 

designs. Please feel free to give your feedback on issues with BIRDS, information on how you 

use BIRDS, and/or what additional features you would like to have in future versions of BIRDS 

by sending an email to birds@nist.gov.
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References

2003 International Energy Conservation Code, 2003, International Code Council, Inc.

2006 International Energy Conservation Code, 2006, International Code Council, Inc.

2009 International Energy Conservation Code, 2009, International Code Council, Inc.

2012 International Energy Conservation Code, 2012, International Code Council, Inc.

Brundtland Commision, 1987, Our Common Future: Report of the UN Commission on 

Environment and Development, Oxford University Press.

Building for Environmental and Economic Sustainability (BEES) Online, 2010, web interface, 

http://ws680.nist.gov/Bees/, Applied Economics Office, Engineering Laboratory, 

National Institute of Standards and Technology.

Building Industry Reporting and Design for Sustainability (BIRDS) v1.0, 2014, web interface, 

http://birdscom.nist.gov/, Applied Economics Office, Engineering Laboratory, National 

Institute of Standards and Technology.

Kneifel, J., Lavappa, P., Greig, A., and Suh, S. 2015. Building Industry Reporting and Design for 

Sustainability (BIRDS) Technical Manual and User Guide for New Residential Database, 

National Institute of Standards and Technology. NIST Technical Note 1878.

Lippiatt, B., Kneifel, J., Lavappa, P., Suh, S., and Greig, A., September 2013, Building Industry 

Reporting and Design for Sustainability (BIRDS) Technical Manual and User Guide, 

NIST Technical Note 1814.