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Energy Resource Library

Illinois Energy Conservation Code

The  Illinois Energy Conservation Code  is the State of Illinois' official building energy code and is based on the 2015 International Energy Conservation Code (IECC), with Illinois Amendments. The City of Chicago has made further amendments. The 2018 International Energy Conservation Code will be adopted in Illinois in 2019.  

FAQs and Further Study

Frequently Asked Questions(FAQ 's) and Technical Notes concerning the 2015 International Energy Conservation Code (IECC), with Illinois amendments and relevant referenced Standards therein, as they apply to the State of Illinois.

Illinois Baseline Compliance Study – Measuring the Baseline Compliance with Residential and Non-Residential Buildings in Illinois against the 2009 & 2012 International Energy Conservation Code

Illinois Resources For Builders & Code Officials

DOE’ s Building Energy Codes Program Compliance Software Tools

  • REScheck : Used to show compliance on residential building plans
  • COMcheck: Used to show compliance on commercial building plans
  • Other forms of compliance may be used as approved by the Authority Having Jurisdiction.
  • USDOE’s Solutions & Help Center – Help with compliance software

More Resources

Are you interested in purchasing a quality home or townhouse in Illinois? Do you want to learn more about how to make your existing home more energy-efficient?

  • Illinois Consumer Checklist -This checklist is designed to help you spot check for compliance with the Illinois Energy Conservation Code. While it does not include every requirement, this checklist will help you assess a home and make an informed decision about the quality of construction and efficiency of a home.
  • Illinois Consumer Guide -This guide provides a quick way to assess home energy performance.The guide describes the minimum standards of construction practice for new homes in Illinois based on the 2012 International Energy Conservation Code (IECC) with amendments as the Illinois Energy Conservation Code.While it does not include every requirement, this will help you assess your own home, and if you are in the market for a new home, make an informed decision about the quality of construction and efficiency for that new home purchase.
  • US DOE’ s Building America Solution Center -The Building America Solution Center provides residential building professionals with access to expert information on hundreds of high-performance design and construction topics, including air sealing and insulation, HVAC components, windows, indoor air quality, and much more.