Multifamily units are now part of ASHRAE’s residential indoor air quality HVAC construction standard.

The American Society of Heating, Refrigeration and Air-Conditioning Engineers says the 2016 version of its standard No. 62.2 includes residential structures like apartments and condominiums, which were previously in the commercial 62.1 IAQ standard in they were four stories or higher.

Residential buildings’ common areas remain in the commercial standard.

Paul Francisco, chairman of the Standard 62.2 committee, said the change was made for consistency.