Standard 90.1 has been a benchmark for commercial building energy codes in the United States and a key basis for codes and standards around the world for more than 35 years. ASHRAE 90.1 (Energy Standard for Buildings Except Low-Rise Residential Buildings) is a US standard that provides minimum requirements for energy efficient designs for buildings except for low-rise residential buildings.
Now the standard is ASHRAE 90.1 and started in 2001. It has since been updated in 2004, 2007,2010, and 2013 due to newer and more efficient technologies. There are many states that apply the ASHRAE 90.1 standard to different buildings that are being constructed or under renovation. Most states apply the standard or equivalent standards for all commercial buildings while others apply the standard or equivalent standards for all government buildings.
There are some states that use other energy conservation standards for all commercial buildings and some other states that use a combination of the ASHRAE 90.1 standard for all government buildings and use other energy conservation standards for their commercial buildings. A few states do not apply any energy conservation standards for their government and commercial buildings.
If you design or build commercial buildings you need this 2013 ASHRAE 90-1 energy standard in your library!