Illinois State Capitol
Photo Credit Jimmy Emerson, DVM

On September 15, 2021, Governor Pritzker signed the Senate Bill 2408, forming the Illinois Energy Transition Act (formerly known as Climate and Equitable Jobs Act, CEJA). One important part of the Illinois Energy Transition Act is a provision to create a state stretch energy code. This will be the first time Illinois has developed a stretch code statewide. The new state stretch code provides a mechanism for jurisdictions to raise the bar for energy efficiency, driving down future energy costs.

What is a stretch code? A stretch code is a mandated code or alternative compliance path that is more aggressive than the base code, resulting in higher energy savings for buildings. In general, municipalities develop stretch codes on their own, or states develop a separate state stretch code. They may be mandatory or may be an optional "stretch code" appendix to the current code. If jurisdictions adopt a stretch code, they become mandatory.

Benefits of a state stretch code

  • Municipalities won't have to devote time and resources to develop their own stretch code.
  • A state stretch code will encourage uniform enforcement and education across jurisdictions.
  • Municipalities who adopt the state stretch code will demonstrate their commitment to climate action.
  • Builders and designers will be encouraged to explore, test, and showcase new energy efficiency strategies and technologies.
  • The adoption of new energy efficiency strategies and technologies will accelerate.
  • Stretch codes can influence what will be included in upcoming model or state codes.
  • Communities that adopt stretch codes will accelerate progress towards becoming net zero.

Who will be developing the Illinois stretch code? The bill directs the Illinois Capital Development Board (CDB) to create a residential and commercial stretch energy code that can then be adopted by municipalities. The bill also requires the Illinois Energy Code Advisory Council to "advise and provide technical assistance and recommendations to the Capital Development Board." If municipalities choose to adopt the stretch code, the code will then take the place of the state energy code for that jurisdiction.  Recommendations for the first stretch code must be completed by July 31, 2023, with the final version ready for adoption by December 31, 2023.

What are the efficiency requirements of the new stretch code? According to the bill, the new stretch code must meet specific performance targets for improved energy efficiency of residential and commercial new construction, beyond the state mandated energy code (right now, the 2018 IECC). Every three years, the performance targets will increase in a predictable manner, as shown in the tables below. The stretch code does not include credit for on-site or off-site energy production.

Table showing stretch code targets for commercial and residential buildings

For example, the residential 2021 IECC without amendments is estimated to be around 40% more efficient than the 2006 IECC. The Residential 2024 Stretch Code would need to be 50% more efficient than the 2006 IECC.

What else does the bill allow?

  • An alternative compliance path through "project certification by a nationally recognized nonprofit certification organization specializing in high-performance passive buildings and offering climate-specific building energy standards that require equal or better energy performance than the Illinois Stretch Energy Code." (e.g., Passive House Institute standard).
  • Utilities are allowed to provide compliance-related education and programming and have these activities count toward their energy savings goals.

Learn more: 

New Buildings Institute: Stretch Codes

Read the bill: SB2408

Illinois Capital Development Board: Illinois Energy Conservation Code

MEEA: Creation of Stretch Code Becomes Law in Illinois