PermitBaseMountain West

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Montana building permits

Adopted codes, fees, and permit requirements for every covered Montana city — browse by county, sourced from official records.

Yellowstone County2 cities covered Missoula County1 city covered Cascade County1 city covered Gallatin County1 city covered Lewis and Clark County1 city covered Flathead County1 city covered Hill County1 city covered Silver Bow County1 city covered Deer Lodge County1 city covered

Montana building permits issuedNew privately-owned residential construction activity by city — U.S. Census Bureau Building Permits Survey, data through 2026-05

Do I need a permit? — Montana guides

Window ReplacementUsually no — but yes if you change the size of the opening.FenceSometimes — many fences need only zoning/setback approval; a building permit kicks in mainly for fences over 7 feet or with structural elements.DeckYes — unless it's a small ground-level platform under 200 sq ft.Water HeaterYes — even for a like-for-like replacement.Basement FinishYes — any framing, electrical, plumbing, or mechanical work requires a permit.Solar PanelsYes — both a building and electrical permit are required.Roof ReplacementYes — all roof replacements and re-roofing projects require a permit.Hot TubYes — at minimum an electrical permit for the 240V circuit.ShedUnder 200 sq ft and under 10 feet tall? Usually no. Bigger? Yes.Furnace ReplacementYes — even a like-for-like furnace swap requires a mechanical permit.EV ChargerLevel 2 (240V) chargers yes. Level 1 (120V plug-in) no.Patio Cover / PergolaSolid roof covers yes. Open-lattice pergolas may be exempt.Home BusinessYes — most cities require a home occupation permit.ADU / In-Law SuiteOften yes — many states now require cities to allow at least internal ADUs.Concrete / DrivewayOnly if it connects to the street, modifies drainage, or is a structural element.

Permit types across Montana

Compare a permit type’s fees across every Montana city we cover.

Accessory Dwelling Unit (ADU) Permit Commercial Permit Deck Permit Demolition Permit Electrical Permit Fence and Retaining Wall Permit Fence Permit Mechanical / HVAC Permit Miscellaneous Building Permit (Fence, Driveway, Sidewalk, Curb Cut)Plumbing Permit Re-Roofing Permit Residential Addition / Remodel / Alteration Permit Residential Addition / Remodel Permit Residential Building Permit (New Construction)Solar Panel Permit Solar PV / Alternative Energy Permit Water Heater Permit