National model energy codes for buildings first appeared in the 1970s, largely due to the energy and economic crises during that decade. Historically high oil prices and the economic shocks that accompanied them prompted Congress to pass 

the Energy Policy and Conservation Act (EPCA) in 1975, which mandated vehicle fuel economy standards, regulated petroleum pricing and directed the creation of strategic petroleum reserves. A 1978 amendment also required states receiving 

federal financial assistance to initiate mandatory programs and measures, including energy conservation standards for 

new buildings.

In 1975, the American Society of Heating, Refrigerating, and Air-conditioning Engineers (ASHRAE) developed the first national energy code, 90-75 “Energy Conservation in New Building Design,” for residential and commercial buildings. The 

next national code to appear was the MCEC 77, a joint effort of multiple organizations under the auspices of the Council 

of American Building Officials (CABO). MCEC 77 was the precursor to the Model Energy Code (MEC) 1983 Edition. The 

CABO released subsequent editions every few years until 1998, when the International Code Council (ICC) International 

Energy Conservation Code (IECC) 1998 became the new residential model code. In 1989, ASHRAE released Standard 90.1-

1989, a complete revision if its previous code, now for commercial buildings only.

The next significant impact on energy codes was the Energy Policy Act (EPAct) of 1992. Amending the EPCA, EPAct required the 

Department of Energy (DOE) to determine whether the most current model energy codes would improve energy efficiency for 

residential and commercial buildings. It also mandated that the 

DOE make a new determination within twelve months for every 

subsequent revision of these codes. Each state would then have 

two years to certify that it had revised its own energy code to 

meet or exceed the requirements of the latest iteration of the 

national models. A state could decline to adopt a residential energy code by submitting a statement to the Secretary of the DOE 

detailing its reasons for doing so.

At the end of 2008, the DOE published its determination for the ASHRAE Standard 90.1-2004 for commercial buildings, 

ruling that energy savings above the previous Standard 90.1-1999 would be 13.9 percent for national source energy and 

11.9 percent for building energy consumption. DOE is currently reviewing Standard 90.1-2007, the most recent national 

model energy code for commercial buildings, and expects to release a determine by early 2010. For ASHRAE Standard 

90.1 2010, ASHRAE has set a 30% improvement in energy savings over the 2004 version as a benchmark. For residential 

and small commercial, the last DOE determination was for the 2000 IECC. At present, DOE is reviewing the 2003 and 2006 

versions. In February of 2009, the ICC released its latest version, which had an estimated 15% increase in energy efficiency over the 2006 version.

Courtesy of DOE-NREL, Credit—Robb Williamson

The Online Code Environment and Advocacy Network

 

Navigating the World of Energy Codes | www.bcap-ocean.org

The History of Energy Codes in the United States

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