In July 2021, The U.S. Department of Energy issued pre-publication Federal Register notice determining that the updated model building energy codes, the 2021 International Energy Conservation Code (IECC) and ANSI/ASHRAE/IES Standard 90.1-2019, will increase energy efficiency in residential and commercial buildings, respectively. DOE analysis estimates the updated code will yield 9.4 percent site energy savings for residential buildings, and 4.7 percent site energy savings for commercial (as compared to the previous respective code edition).
Supporting technical analysis, as well as links to the Federal docket and public comments received, are available at: https://www.energycodes.gov/