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Illinois Adopts 2012 IECC Code

Illinois became the first state in the country to adopt the 2012 International Energy Conservation Code as its mandatory statewide building energy code, set to take effect January 1, 2013¹.  The 2012 IECC was adopted in its entirety, with minor adjustments on the residential code, after the Illinois Joint Committee on Administrative Rules approved the new rules on December 11, 2012².

MEEA is pleased with this outcome, as our building codes team, led by Isaac Elnecave, along with many other advocates in the state and region have worked hard to encourage adoption of more efficient building policies.  MEEA collaborated with other organizations, such as Environmental Law and Policy Center, Illinois chapter of American Institute of Architects, and Chemical Industry of Illinois to provide support and advocacy to stakeholders during this process.  This development means that Illinois will be a leader, both in the Midwest and around the nation, for energy efficiency in new building construction.

Compared to the previous code, residential and commercial buildings will see energy savings of roughly 12% and 20% respectively. Moreover, these significant energy savings will continue to accumulate over the life of each new building.  MEEA’s energy codes department will hope to build on this success as we look to promote energy efficiency through sensible building policies and increased code compliance in our region in the next year.


¹Maryland previously adopted the 2012 IECC, however the code must be adopted separately by local jurisdictions.

²The amendments to the 2012 IECC that Illinois adopted can be found here:  There is a relaxed requirement for air leakage testing – 5 ACH50, rather than 3. Additionally, the requirement for conditioned basement wall insulation has been modified, stating that walls shall be insulated down to 4 feet below grade, rather than 10.