National model energy codes are developed and published on a three-year cycle. The two most widely adopted energy codes are the International Energy Conservation Code (IECC) and ASHRAE’s Energy Standard for Buildings Except Low-Rise Residential Buildings (ASHRAE 90.1).

After an energy code is published (IECC for residential and ASHRAE 90.1 for commercial and multifamily above three stories in height), the Department of Energy compares the latest edition of the code to the previous edition to determine if the code has become more energy efficient. A positive determination by DOE triggers a series of requirements that are outlined in the DOE Determinations State Certifications Fact Sheet.

When a state or jurisdiction goes through the adoption process for an energy code, there are typically public hearings and an opportunity to amend the code prior to adoption. NAHB has developed a series of adoption kits that include highlights of changes from the previous code, associated cost increases and a list of suggested amendments that offer more cost-effective and affordable energy conservation code provisions than available in the model codes. You can find them listed by year in the Code Adoption section. In this section, NAHB provides additional resources to help bolster your arguments and bring common sense to the code adoption process – and correct the misinformation that still exists.

These resources also bring clarification to the American Recovery and Reinvestment Act (ARRA) which requires a state to adopt an energy code by 2017 that is “equivalent to” or “meets or exceeds” the 2009 IECC. That means that jurisdictions can continue with the 2009 energy code with the NAHB amendments, even though the jurisdiction may adopt later versions of other ICC codes.

This DOE Determinations State Certifications Fact Sheet also explains other federal requirements.

Energy Code Adoptions by State

ARRA and Energy Codes

Log Homes and Energy Code

Energy Code Adoption Cost Analysis

DOE Determinations