The next version of the ANSI/ASHRAE/IES 90.1 standard for energy efficiency in new commercial buildings won’t have greenhouse gas-related addenda that were added last year, reflecting a shift among the standards-writing organizations to refocus the standard on its core mission. “Standard 90.1 will maintain its primary focus on energy efficiency and energy cost justified requirements,” AHRAE said in announcing the change last month. The standard, which provides minimum requirements for energy-efficient design and construction of new sites and buildings and their systems, as well as criteria for determining compliance with these requirements, serves as a key benchmark for commercial building energy codes in the U.S. and around the world. Addenda M and N, which the organizations added last year to provide standards on curbing greenhouse gas emissions, will remain as part of an optional publication, giving jurisdictions “a template for … reducing operational emissions [and using] renewable energy,” ASHRAE said. Splitting off greenhouse-gas reductions as optional addenda enables the standard to “respond to emerging market needs without losing sight of the proven energy efficiency principles at the heart of Standard 90.1,” ASHRAE President Sarah Maston said in a statement. Standard 90.1 was released in the 1970s and is officially known as the Energy Standard for Buildings Except Low-Rise Residential Buildings. It’s updated on a three-year cycle, with the next versions slated for 2028 and 2031. Adding the emission-related addenda last year and then making them optional this year reflects shifting priorities of stakeholders, including the U.S. Department of Energy, which is part of the standards-writing committee. “Are they telling us what to do on this or that? No,” Tom Culp, a Wisconsin-based building glass expert and co-vice-chair of the Standard 90.1 committee, told Facilities Dive. But “one of the mantras [we have as a committee] is ‘transparency, affordability and choice’