Tiny Homes Zoning — State ProfileReviewed 2026-08-23
Can you put a tiny home in Montana?
Current tiny-home-on-wheels and ADU rules for Montana, sourced and dated — plus verified local builders.
GENERALLY ALLOWED
Montana — Statewide code exists, but local enforcement is optional (verified 2026-08)
Tiny home on wheelsMontana has adopted statewide building codes (2021 IBC/IRC and related codes, administered by the Dept. of Labor & Industry's Building Codes Program) — this corrects an earlier draft that said the state had no statewide code. The practical flexibility comes from a different mechanism: cities and counties choose whether to become a 'certified' jurisdiction that enforces the code locally. Uncertified rural areas often have no local permitting or inspection in practice, even though the state code technically applies.
ADU / accessory unitADU rules apply mainly within certified cities and counties (Bozeman, Missoula, Billings, Gallatin County, etc.); uncertified rural areas are generally the more flexible option in practice.
Minimum square footageNo statewide minimum; varies where locally enforced
Foundation requirementStatewide code applies in principle everywhere; enforcement in practice depends on whether the local jurisdiction is certified
Local notesThis is a meaningful correction from an earlier draft: Montana isn't a 'no code' state — it's a state where enforcement, not the existence of a code, is what varies by jurisdiction. Confirm certification status with the specific county before assuming no inspection will be required.
!Zoning is set by your specific city or county, not the state as a whole. Use this as a starting point, then confirm with the local building or planning department before you buy land or start a build. Not legal advice.
Last reviewed 2026-08-23