A stretch code is a more demanding code than a base code that some jurisdictions elect to adopt to gain
greater energy savings. They generally emphasize performance over prescriptive compliance. In Illinois,
the Illinois Energy Transition Act (IETA) establishes the minimum energy efficiency levels required by the
Illinois Stretch Code .

Illinois Energy Transition Act (eff. 9-15-2021) is a comprehensive piece of Illinois energy legislation. The IETA includes a provision to create an IL state stretch energy code.