The Rocky Mountain Institute (RMI) has launched a new online calculator to help architects, designers, and builders achieve carbon emission reduction goals for new construction and retrofit residential and commercial projects. Called Green Footstep, the free carbon calculator allows designers to address multiple sources of carbon emissions over a building's lifetime and estimate the impact of specific design decisions in the quest for carbon neutrality.

In addition to carbon neutrality and net-zero site energy performance goals, Green Footstep also helps designers comply with the U.S. Green Building Council's LEED energy credit guidelines and the goals of Architecture 2030's 2030 Challenge.

Green Footstep gives designers the tools to make more informed design decisions by allowing them to estimate a building's life cycle carbon footprint. The program accounts for a project site's intrinsic carbon storage and weighs it against the carbon emissions generated by site preparation, construction, and operation of the building. Users can see the areas in which their projects fall short of carbon reduction or energy performance goals and make changes accordingly.

"Green Footstep allows designers to adjust design targets, such as building energy use intensity and incorporating more renewables, that will get the building out of carbon debt, edging the building closer to carbon neutrality," says Michael Bendewald, the RMI analyst who developed the calculator, in a statement announcing the online tool.

RMI recommends designers, builders, architects, and other users employ Green Footstep for a project as early as the pre-design phase and then test multiple target design changes, as necessary, throughout the design process. Users simply input project information—including location, site characteristics, and building characteristics—and the program generates a carbon emissions building performance report.

The Green Footstep Web site also offers building case studies revealing how the program has helped other projects reach carbon reduction goals. By creating a free account, users can input project information and goals, save them, and revisit them to make changes or updates. To learn more about using Green Footstep, click here.

Stephani L. Miller is Associate Editor of Residential Architect magazine.