BIRDS - Incremental Energy Efficiency for Residential Buildings

BIRDS - Building Industry Reporting and Design for Sustainability - allows users to compare the sustainability performance of a new building as the energy efficiency design of that building type changes.

In BIRDS, sustainability performance includes:

  • operating energy use
  • life-cycle environmental performance of the building's materials, construction, and use
  • life-cycle cost performance
  • indoor environmental quality such as thermal comfort and indoor air quality

For this BIRDS database, a user can compare the sustainability performance of 960,000 different building component combinations for the NIST Net Zero Energy Residential Test Facility (NZERTF) located in Gaithersburg, MD. BIRDs v4.0 added options for natural gas-fired space and water heating equipment and a larger solar PV system option. The NZERTF Design as operated during its initial year of demonstration was added as a predefined selection option along with the IECC editions. Future versions will expand on the current options by introducing alternative foundation types, new building prototypes, and locations.

Note: BIRDS does not allow for comparisons of performance across different use profiles (e.g. occupancy activity) for the NZERTF.

Steps to getting answers to your sustainability questions.

  1. Begin by telling BIRDS about the baseline building you are interested in.
  2. Tell BIRDS about the alternative designs to compare to the baseline.
  3. See how different aspects of sustainability for your building change as its energy efficiency changes.

Access an introductory tutorial, documentation, and FAQ at the top right corner of the page.

In this step, select your assumptions and baseline building design for which you want to complete an evaluation.
My Baseline Assumptions
NZERTF Residential Test Facility

Select the building components you would like to use as your baseline building design. Select a building design based on an edition of IECC (2006, 2009, or 2012/2015) or a custom design. The options available for customizing building components are based on requirements set by different editions of IECC and the NZERTF specifications. The most efficient option for each building components is associated with the NZERTF design. One approach to a custom design is to start with an edition of IECC and then changing specific components. For further guidance, View the Tutorial.

Select any alternative building component properties you would like to compare to the baseline design. Every combination of the selected alternatives and the baseline building will be included in the reported results. As with the baseline building design, a user can compare designs based on editions of IECC or a user-defined custom design. Answer the two questions below to begin selecting alternatives. View Tutorial for additional guidance.
My Building Comparisons

The alternative components defined in all selected IECC editions above have been automatically selected. Please select any additional alternatives you would like to compare to the baseline. All combinations of the baseline and alternative selections will be reported in the results.

Select Environmental Preferences you want to compare.
My Environmental Preferences

Select your environmental preferences by setting the weights for each of the environmental impact categories.

BIRDS includes 12 environmental impact categories for which the user can analyze the environmental performance of a building. BIRDS also allows a user to report a single, weighted average Environmental Impact Score (EIS). In order to calculate the EIS the user must define their preferences, or "weight set" regarding the relative imporance of each environmental impact. The user can select one of the pre-defined weight sets or create their own weight set.

Climate Change
Ozone Depletion
Source Energy
Land Use
Water Consumption
Sum must equal 100.
Environmental Impacts BEES Stakeholder Panel Carbon Footprint Only EPA Advisory Board Equal Weights
HH_Cancer 8 0 8 8.3
Climate Change 30 100 18 8.3
Acidification 3 0 5 8.3
HH_Respiratory 10 0 7 8.3
HH_Noncancer 5 0 5 8.3
Ozone Depletion 2 0 5 8.3
Eutrophication 6 0 5 8.3
Smog 4 0 7 8.3
Ecotoxicity 7 0 12 8.3
Source Energy 11 0 7 8.3
Land Use 6 0 18 8.3
Water Consumption 8 0 3 8.3
View Results

Download Data

Retrieving data... may take a few minutes.

Summary Table

The summary table identify the characteristics (top table) and performance values for the sustainability metrics (bottom graph) of "key" building designs that target goals the user may be interested in reaching (e.g. minimize life-cycle cost or reach net-zero with the lowest life-cycle costs).

Characteristics of Key Building Designs

Results for Key Building Designs (visually shown in the Radial Charts tab)

Scatter Plots

The scatter plots compare the energy savings obtained from a given building (relative to the baseline building) to the resulting life-cycle costs and initial investment costs for the given building design.

Radial Charts

The radial charts compare the key building designs relative to the baseline across the sustainability metrics shown in the summary tables (top chart) and the 12 environmental impact categories (bottom chart).

Bar Graphs

The bar graphs allow a user two different types of comparisons: (1) compare performance for the selected IECC code editions relative to the baseline design or (2) determine how performance changes a specific building component is changed using the baseline and alternatives selected in Step 2 for that specific building component (all other components are assumed to be the baseline design).