GREEN FOOTSTEP: CALCULATIONS AND DATA SOURCES

This research paper details the calculations and data sources used by Green Footstep, an online tool designed to assess and reduce carbon emissions from building construction projects. The methodology focuses on achieving carbon neutrality by ensuring that the net carbon stored on a project site by the end of its analysis period is equal to or greater than the carbon stored in its native state.

• Green Footstep defines carbon neutrality as a state where the net amount of carbon stored on a building project site is equal to or greater than the native amount by the end of the project analysis period.
• The tool calculates net carbon flow by accounting for three primary emission sources: site development (removal or addition of vegetation), construction (raw material extraction, manufacture, transport, and assembly), and operation (Scope 1 and 2 emissions from electricity, natural gas, and other fuels, with optional Scope 3 emissions like commuter transport).
• Native site carbon storage is estimated using IPCC data for forest and grassland land types, though the document notes a lack of available data for other land types and a failure in existing studies to account for underground biomass, which can represent up to 80 percent of total biomass.
• Emissions from site development are calculated by comparing design-case carbon storage against native-state storage. For non-native areas, the tool uses an average tree growth rate over 20 years, estimating 0.2 metric tons of carbon (0.73 t CO2e) per tree.
• For construction emissions, the tool offers an Economic Input-Output Life Cycle Assessment (EIO LCA) option based on 1997 US economy data. This can be applied via two approaches: using carbon emissions per US dollar of construction activity for both new and renovation projects, or using carbon emissions per square foot for new construction only.
• Operational emissions are calculated by estimating energy use (using EPA eGRID for electricity and EIA for natural gas) and subtracting offsets from on-site or purchased renewable energy and carbon offsets.
• A historical comparison between 1967 and 1997 data indicates that energy intensity in building construction decreased by approximately 30% for new residential 1-unit, new multifamily, and manufacturing/industrial sectors, while it increased by 15% for commercial and institutional buildings.

APA

Bendewald, M., & Olgyay, V. (2011). GREEN FOOTSTEP: CALCULATIONS AND DATA SOURCES. RMI. https://rmi.org/app/uploads/2017/05/RMI_Document_Repository_Public-Reprts_2011-11_GreenFootstep.pdf

Chicago

Bendewald, Michael, and Victor Olgyay. GREEN FOOTSTEP: CALCULATIONS AND DATA SOURCES. RMI, 2011. https://rmi.org/app/uploads/2017/05/RMI_Document_Repository_Public-Reprts_2011-11_GreenFootstep.pdf.

Wikipedia

{{cite report |last1=Bendewald |first1=Michael |last2=Olgyay |first2=Victor |title=GREEN FOOTSTEP: CALCULATIONS AND DATA SOURCES |publisher=RMI |date=July 2011 |url=https://rmi.org/app/uploads/2017/05/RMI_Document_Repository_Public-Reprts_2011-11_GreenFootstep.pdf |access-date=17 August 2026 |via=Climate Insights Directory}}

BibTeX

@techreport{bendewald2011green, author = {Bendewald, Michael and Olgyay, Victor}, title = {{GREEN FOOTSTEP: CALCULATIONS AND DATA SOURCES}}, institution = {RMI}, year = {2011}, month = jul, url = {https://rmi.org/app/uploads/2017/05/RMI_Document_Repository_Public-Reprts_2011-11_GreenFootstep.pdf}, urldate = {2026-08-17}, note = {Indexed by Climate Insights Directory} }