2021 edition of code establishing a baseline for energy efficiency by setting performance standards for the building envelope (defined as the boundary that separates heated/cooled air from unconditioned, outside air), mechanical systems, lighting systems and service water heating systems in homes and commercial businesses., For the United States, the ANSI/ASHRAE Standard 169 climate zone map is reproduced below. A list of counties and their respective climate zones can be found in Table B1 in ANSI/ASHRAE Standard 169., Revising Climate Zone Map Counties moving from Climate Zone 7 to Zone 6A, In the 2016 version, ASHRAE 90.1 introduced a new climate zone map with shifting boundaries. Likewise, the IECC updated the map in its 2021 version to align with the ASHRAE 90.1 standard., This U.S. map shows which counties have been assigned to a different climate zone for purposes of building and energy codes. Counties marked in red are now in warmer climate zones with less stringent energy requirements., The first edition of ASHRAE Standard 90 was published in 1975; the most current version is ASHRAE/IESNA Standard 90.1.Many countries worldwide have based their commercial BEECs on a version.