Commercial and residential buildings account for approximately 41% of all energy consumption and 72% of electricity usage in the United States. Building energy codes and standards set minimum requirements for energy-efficient design and construction for new and renovated buildings, assuring reductions in energy use and greenhouse gas emissions over the life of buildings. The U.S. Department of Energy (DOE), through the Building Energy Codes Program (BECP or the Program), supports the improvement of energy efficiency in buildings.
BECP periodically assesses the impacts of its activities by estimating historical and projected energy savings, consumer savings, and avoided emissions. The Pacific Northwest National Laboratory (PNNL) conducted the codes benefits assessment in support of the BECP. Underlying the assessment is a series of calculations that estimate and compare energy savings under two scenarios: "with BECP" and "without BECP." The analysis covers the years 1992-2040 and includes comparing the nominal energy savings (assuming 100 percent adoption and compliance) attributable to different code versions, determining the applicable floor space (both residential and commercial) subject to the code, and estimating the final energy savings by adjusting nominal energy savings for the applicable floor space according to the estimated actual adoption and compliance levels. The resulting estimates of energy consumption for each scenario are compared, and the difference equals the impact of BECP activities.