cove.tool's carbon emissions & CO2 percent reduction metric is calculated using carbon emissions factors local to your State or Country (domestic) or Country, Territory, Province, State (international). The calculation method for the emissions factor can be seen here. These factors are applied to the electricity usage of the project and a constant value is used against the Gas usage.
The 2030 Baseline emissions are calculated using Architecture 2030's ZeroTool.org, energy consumption, and the carbon emissions factors. The project CO2 Percent Reduction is calculated using the 2030 Baseline and your emissions results, giving users a tangible idea of the environmental impact their energy-efficient projects can have.
Where is the carbon emission factor sourced from?
For USA locations, the web app uses the EPA eGRID database and for Canada locations, Canada's National Inventory Report defines the carbon factors. Equivalent databases are used for international locations such as the Annual Climate Transparency Report. Snapshots of database breakdown can be seen below.
What is ZeroTool?
Architecture 2030 developed Zero Tool to compare a building’s design or an existing building’s energy use intensity (EUI) with similar building types, understand how a building achieved its EUI (via energy efficiency, on-site renewable energy, and/or green power purchases), and set EUI targets.
Find out more here: https://zerotool.org/about/