The International Energy Conservation Code® (IECC®)

Background: State and Local Adoption of Building Energy Codes

The development of the International Energy Conservation Code® is based on experiences gained through decades of code developments. The energy shortages of the 1970’s motivated many states and local jurisdictions to add provisions to building codes to make homes more energy-efficient. State and local building energy codes have proven successful in reducing energy consumption and peak electric demand in residential buildings, through the use of energy-efficient windows, added insulation, and reduced air leakage. These codes have become integral parts of almost every state and local jurisdiction’s building code.

States and local jurisdictions most often look to national model energy codes as the starting point for their own codes. Simply adopting model energy codes makes it easier for them to keep current with the most recent building practices and technology. In the 1992 Energy Policy Act (“EPAct”) Congress mandated that all states must review and consider adopting the national model energy standard (at that time, the 1992 Model Energy Code). Since then, new model energy codes have been developed and in 1998 the first International Energy Conservation Code® (IECC®) was released. This 1998 IECC was followed by versions that produce even greater energy savings: the 2000 IECC with its 2001 supplement and the 2003 IECC with its 2004 supplement. All of these have been published by the International Code Council®. The latest version of the IECC was released in early 2006.

What is the International Energy Conservation Code®?

The IECC® is a model energy building code produced by the International Code Council® (ICC®). It is referred to as a “model” code because it was developed through a public hearing process by national experts under the direction of the ICC.
The code contains minimum energy efficiency provisions for residential and commercial buildings, offering both prescriptive- and performance-based approaches. The code also contains building envelope requirements for thermal performance and air leakage. The IECC is part of the International “family” of Codes produced by the International Code Council®, which includes other codes such as the International Building Code® (IBC®), International Residential Code® (IRC®), International Mechanical Code® (IMC®), International Plumbing Code® (IPC®), and more.

According to the International Code Council, the intent of the IECC is to establish an energy conservation code that:

	Effectively conserves energy
	Minimizes increases in construction costs

	Allows the use of new materials, products or methods of construction
	Eliminates preferential treatment for particular industries or types or classes of materials, products or methods of construction

For an overview of the 2000 IECC®, click here.
To purchase a copy of the IECC®, visit the ICC Online Store.
For an assessment of the changes to the IECC® since 2003 click here.
To find out about the status of building codes in the states, visit the BCAP website.
Information on building codes in the states may also be found on the DOE Status of State Energy Codes website.

Answers to Common Code Questions:

• Why Are Building Codes Important?
Building codes, of which building energy codes are an essential part, are important primarily because they work to increase the public safety and result in improved building construction. By providing uniformity in construction laws, building codes set minimum standards that will consistently produce safely constructed buildings. Building codes also promote use of new materials and building techniques.

• Why Are Building Energy Codes Important?
Building energy codes are important because they set meaningful thresholds for all new construction and existing buildings, such as:

Windows: maximum U-factors and SHGCs for windows, doors and skylights.
Insulation: minimum levels of insulation for walls, ceilings, floors, foundations and ducts.
Infiltration: require proper sealing.
Equipment: require proper HVAC equipment sizing.

In addition, these codes ensure a baseline level of comfort and energy performance for all homes.

• Which States Have Adopted the IECC?
To view a map that demonstrates which states have adopted the IECC, click here. The map should not be relied upon solely, as it does not account for state or local amendments. To determine the building energy code requirements that apply in your area, consult your local building code official.