IECC Adoption

The International Code Council serves as the voice of the U.S. building safety and regulatory community in a variety of international dialogues related to safety and resilience in the built environment.

The Code Council’s commitment to energy conservation dates back to the 1970s when its legacy organizations first began developing model energy codes. The Model Energy Code (MEC) — the predecessor to the 1998 IECC — applied to all new residential and commercial buildings, and additions to such buildings.  

Each new edition of the energy code has provided for the cost-effective reduction of energy use.  

Energy codes are an essential component in a state or local government’s plans or commitments for renewable energy deployment, climate goals, housing affordability and public health. The U.S. Conference of Mayors stated, “building energy codes, by setting minimum efficiency requirements for all newly constructed and renovated residential, multi-family, and commercial buildings, provide measurable and permanent energy savings and carbon emissions reductions over the century-long life spans of these buildings;”

Communities that regularly adopt the IECC save money for residents and business and improve community health and resilience. Some jurisdictions routinely augment the most recent model code with additional energy-saving code provisions or programs 

States are required to review their residential energy code and update their commercial energy code within two years of a positive determination from the Department of Energy that a new edition of the IECC or ASHRAE Standard 90.1 saves energy. 

Across the U.S., the average new home built to the 2021 IECC can save homeowners thousands of dollars a year.

Adopting the 2018 International Energy Conservation Code Can Save New Homeowners Hundreds of Dollars a Year

According to analysis by the Department of Energy (DOE) Pacific Northwest National Laboratory (PNNL), the average new home built to requirements in the 2021 IECC will save residents of most states hundreds or even thousands of dollars a year in energy bills over homes built to the currently adopted energy code.

On average, any increase in cost is recouped in the first year. When wrapped into a down payment and financing, the annual cost increase is dwarfed by the annual energy savings—indicating that following code requirements can play an important role in improving housing affordability.

The map below provides annual energy cost savings for the average new home along with other important data. DOE provides Impact Analysis for the adoption of the 2021 IECC, as well as National and State Analysis which the below map draws from. Data current as of July 2021.

IECC Benefits Map

Click your state to see how much you can save by adopting the 2021 IECC.

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IECC Benefits
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Analysis assumptions:

  • Mortgage interest rate (fixed rate) 5% annual rate
  • Loan fees 0.7%, initial, % of mortgage amount
  • Loan term 30 years
  • Down payment 10%
  • Nominal Discount rate 5%
  • Inflation rate 2.52%
  • Marginal federal income tax 12%
  • Property tax 1.5%

Note: While a state may have adopted an energy code, it may not be applicable in all local jurisdictions. Consult for information on state and local adoptions.