Montana Statewide Rule
Montana State Building Code Governs Tiny House Construction
Key Facts
- Statute
- MCA Title 50, Ch. 60
- Foundation standard
- IRC Appendix Q
- On wheels
- RV classification
- Administrator
- DLI Building Codes
Summary
Montana adopts statewide building and residential codes through the Department of Labor and Industry. Tiny houses on foundations follow IRC Appendix Q, while RV-classified tiny homes on wheels are regulated as recreational vehicles under state law.
(1) (a) Within the unincorporated portions of a jurisdictional area that has been established under provisions of 76-1-501 through 76-1-503 or 76-1-504 through 76-1-507 and for the purposes provided in 76-2-201, the board of county commissioners may by resolution establish zoning regulations for a part or all of the jurisdictional area or divide the county into zoning districts with zoning regulations that are considered best suited to carry out the purposes of this part. By establishing zoning regulations, the board may regulate the erection, construction, reconstruction, alteration, repair, location, or use of buildings or structures or the use of land, including the creation of zoning districts that allow tiny dwelling units.
Full Breakdown
Title 50, Chapter 60 MCA establishes the Montana State Building Code, administered by the Department of Labor and Industry's Building and Measurement Standards Bureau. Montana has adopted IRC Appendix Q, which provides minimum standards for dwellings under 400 square feet on permanent foundations. Tiny houses on wheels meeting RVIA or NFPA 1192 standards are regulated as recreational vehicles, not dwellings, and cities cannot impose dwelling code requirements on them. Manufactured tiny homes fall under HUD-code rules at MCA 50-78. Local zoning still controls placement, lot size, and use.
Violations & Penalties
Building or occupying a tiny home without proper permits, inspections, or code compliance may trigger stop-work orders, fines, and removal under MCA 50-60-107.
Frequently Asked Questions
Are tiny houses on wheels legal as primary residences in Montana?
What size triggers Montana's tiny house rules?
Sources
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