YES — Montana has adopted 2021 IECC which requires HVAC loads be calculated per ACCA Manual J for new construction and major renovations.
Montana has adopted 2021 IECC as the statewide energy code for residential construction.
Covers the entire state including Billings and Missoula
Local Montana 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. Montana 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 Montana instantly at AutoHVAC — upload your blueprint and receive a permit-ready report in 60 seconds. Alternatively, local Montana HVAC contractors charge $150-400 with 3-7 day turnaround, or you can use DIY software like Wrightsoft or CoolCalc ($5-200+/month).
Montana includes IECC climate zone 6B. This zone covers the entire state including Billings, Missoula, Great Falls. Climate zone data determines design temperatures and insulation requirements used in Manual J calculations.
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