How Portfolio Manager Calculates Greenhouse Gas Emissions

You have two options for calculating your building's greenhouse gas emissions.

Option 1: Within Portfolio Manager

Portfolio Manager calculates your building's greenhouse gas emissions (including carbon dioxide, methane, and nitrous oxide) from on-site fuel combustion and purchased electricity and district heating and cooling. Portfolio Manager also enables tracking of avoided emissions from any green power purchases.

The methodology for calculating greenhouse gas emissions in Portfolio Manager was designed to be consistent with the Greenhouse Gas Protocol developed by the World Resources Institute and World Business Council for Sustainable Development, and is compatible with the accounting, inventory, and reporting requirements of EPA’s Center for Corporate Climate Leadership, as well as other state and NGO registry and reporting programs.

On December 11, 2022, EPA began calculating GHG emissions using historical GHG factors for all fuel types. For example, 2015 emissions are calculated using 2015 emissions factors. Prior to this change, Portfolio Manager use the most current GHG emissions factors for calculations for all prior years.

While the emissions calculations are based on the amount and type of energy your building consumes, emissions have no bearing on a building’s 1 – 100 ENERGY STAR score or other energy metrics.

For more detailed information on emissions calculations, refer to the technical descriptions available in the following documents:

Option 2: Building Emissions Calculator

Our Building Emissions Calculator is a web-based tool that can automatically calculate and display your building’s GHG emissions in several different GHG-Protocol-compliant ways. You can make changes, including applying custom or locality-specified emissions factors to estimate their impact on emissions. You can also forecast emissions by making changes to your building’s efficiency, fuel mix, renewable energy use, and emissions factors. All results are displayed on a graph and in a table, and you can download the results.

To get data into the tool, you can choose to have it imported directly from your Portfolio Manager account or enter it manually. However, while you can download and save your results in Excel, neither your inputs nor your results will be saved within the calculator itself or Portfolio Manager. 

Commercial Buildings