White House and the U.S. Department of Energy (DOE) released a draft national definition for a zero-emissions building following up on an announcement initially made at the Greenbuild International Conference and Expo. The intention of the definition is to serve as a common framework for greater market alignment to move the building sector toward zero emissions.
According to the U.S. Green Building Council (USGBC), The initial definition focuses on operating emissions, although DOE notes that embodied carbon, refrigerant impacts and grid-interactive equipment may be addressed in subsequent updates. The definition consists of three principles that characterize a zero operating emissions building:
- Highly energy-efficient: For existing buildings, energy performance in the top 25% most efficient buildings in the market with a similar use, based on measured whole-building energy use. For new buildings, estimated whole-building energy use is at least 10% lower than the latest IECC or ASHRAE 90.1 model code, and the building is designed to achieve energy performance in the top 10% of similar buildings (i.e., an ENERGY STAR score of 90 or higher).
- Free of on-site emissions from energy use: The building’s direct GHG emissions from energy use equal zero.
- Powered solely from clean energy: All the building’s energy is from carbon-free sources (which can include on-site generation and off-site sources, including market mechanisms such as renewable energy certificates under certain conditions).