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Montana residential energy code
Montana residential energy code (2021 IECC with Montana amendments)
As of 2026-10-22. DOE's Building Energy Codes Program (energycodes.gov) lags state adoption, so where a state's own rule was read it governs and DOE's differing figure is noted. Residential means one- and two-family dwellings and townhouses. Local amendments can apply; check the code body before relying on a section.
Key features
- Code in force: 2021 IECC with Montana amendments
- In force since: 2022-06-10
- Adoption: Statewide mandatory code
- DOE lists an effective date of 2024-09-21; the Montana DEQ page gives 2022-06-10.
- Verified against the state's own adopted rule or code-body page.
Governing body
State of Montana
Region
MT
Category
code