YES — Illinois has adopted 2021 IECC which requires HVAC loads be calculated per ACCA Manual J for new construction and major renovations.
Illinois has adopted 2021 IECC as the statewide energy code for residential construction.
Primary zone covering Chicago and surrounding areas
Additional zone in Illinois
Local Illinois contractors typically charge $150-400 for Manual J calculations. AutoHVAC offers your first Manual J calculation completely FREE with permit-ready results in 60 seconds — no credit card required.
Yes. Illinois follows 2021 IECC which requires heating and cooling loads be calculated per ACCA Manual J for permits on new construction and major HVAC work.
You can get a free Manual J calculation for Illinois instantly at AutoHVAC — upload your blueprint and receive a permit-ready report in 60 seconds. Alternatively, local Illinois HVAC contractors charge $150-400 with 3-7 day turnaround, or you can use DIY software like Wrightsoft or CoolCalc ($5-200+/month).
Illinois includes IECC climate zones 4A, 5A. Zone 4A is most common, covering cities like Chicago, Aurora, Naperville. Climate zone data determines design temperatures and insulation requirements used in Manual J calculations.
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