ASHRAE has announced a shift in direction for Standard 90.1, the benchmark reference for commercial building energy efficiency in the United States for more than five decades. The core change moves the provisions focused on reducing operational carbon — added through Addenda M and N of the 2025 edition — into a separate, optional publication, while Standard 90.1 itself will keep its original focus on energy efficiency and on technical requirements justified by cost-effectiveness.
As part of the restructuring, ASHRAE will develop a companion document offering a voluntary framework for states, cities, and companies seeking to cut their operational greenhouse gas emissions, without altering Standard 90.1’s role as a mandatory, code-referenced benchmark. The organization said the move responds to the growing diversity of regulatory requirements across jurisdictions, many of which have begun demanding carbon metrics that go beyond the standard’s traditional energy-efficiency scope.
ASHRAE’s 2026-2027 president, Sarah E. Maston, said the new direction strengthens the foundation that has made 90.1 one of the world’s most influential building energy standards. Development of both documents will continue through the 2028 and 2031 work-plan cycles, with public review opportunities before final publication.
Source: ASHRAE
