U.S. housing and agriculture department-approved structures will be required to meet the energy-efficiency guidelines included in ASHRAE’s updated Standard 90.1 under a bill signed by President Bush last month.

HUD and the USDA are required to create efficiency standards for public housing and homes with federally insured mortgages. Previously, the standards had to at least meet the 1989 version of Standard 90.1, “Energy Standard for Existing Buildings Except Residential,” and were supposed to be updated within a year of any revisions. However, new standards were rarely enforced, according to the American Society of Heating, Refrigerating and Air-Conditioning Engineers.

The new requirements, which will mandate using the 2004 version of Standard 90.1, were included in the landmark energy bill signed by Bush Dec. 18. It also hiked automobile fuel economy standards, authorized regional efficiency standards for HVAC equipment and will phase out incandescent light bulbs in favor of compact florescent models.

The only exceptions to the new requirements are cases where the new standards would make housing less affordable or available.

“This provides additional validation of the importance of energy savings in Standard 90.1 and also provides a base line for all public and assisted housing, and federally insured mortgage property in all states,” said Doug Read, ASHRAE’s director of government affairs.