Standard 90.1, the energy conservation standard published by the American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE), has been approved by the American National Standards Institute (ANSI).

ANSI/ASHRAE/IESNA Standard 90.1-1999, Energy Standard for Buildings Except Low-Rise Residential Buildings, provides the minimum requirements for the design of energy efficient buildings.

Standard 90.1 had previously been approved by ANSI but that approval was appealed by the American Gas Association (AGA), which was supported by the Natural Resources Defense Council. ANSI denied the AGA appeals, which means the Institute has determined that the standard has met the consensus requirements set by the accrediting standards-writing organization.