Butte-Silver Bow building department

Butte-Silver Bow is a consolidated city-county government, and its Building and Code Enforcement office is the local building authority. Montana’s Building Codes Program lists Silver Bow as a certified program, with a county-wide jurisdiction, for building, plumbing, mechanical, and pool codes. Electrical is not on that list. The office approves plans and issues commercial, residential, mechanical, plumbing, and sign permits. It works out of Room 108 of the courthouse.

Who issues which permit

Here is how the work splits:

• Butte-Silver Bow: building, plumbing, mechanical, roofing, demolition, sign, and moving permits.
• State of Montana: electrical permits. Silver Bow isn’t certified for electrical, so they come from the Montana Building Codes Bureau, and state electrical inspectors do the inspections. A homeowner can wire their own home, garage, and premises under a state homeowner’s electrical permit. All other electrical work needs a Montana-licensed electrical contractor.
• Other local offices: the county’s 2023 residential permitting presentation lists several other permits. Planning checks zoning and assigns addresses. Public Works handles right-of-way and encroachment permits. The Health Department handles sewer taps, wells, and septic.
• Excavation: a $10 flat-fee excavation permit is required any time soil is disturbed. It is reviewed for floodplain and for the Superfund area, and the Superfund Department may test the soil.

The same presentation says a permit is needed to build, enlarge, alter, repair, move, or demolish, or to change occupancy. The exceptions are the ones in IRC 105.2.

Homeowner plumbing and mechanical rules

Butte-Silver Bow’s 2025 checklists set these rules:

• Plumbing by the owner: a homeowner may do plumbing without a permit only on their own primary residence. On new homes, the owner must also have no intent to sell.
• Rentals and investment properties: the owner can’t do the plumbing. It must be done by a licensed plumber.
• Licensed plumbers: they must pull a permit any time new pipe goes in, including drain-waste-vent and water lines.
• Mechanical work: both homeowners and contractors must pull a permit to replace any mechanical system or ductwork. That includes furnaces, boilers, wood stoves, and pellet stoves.

Applying through GovWell

Building permits and business licenses are submitted online through GovWell. The county posts how-to guides for creating an account, submitting an application, navigating the portal, and paying fees. Partial packages are not accepted. Submit the checklist with your package.

A new home needs:

• A site plan showing distances to every property line
• Foundation, floor, structural floor framing, and roof framing plans, with stamped trusses
• Wall sections from footing to roof peak
• Energy details: ceiling, wall, and foundation insulation R-values

A remodel needs existing and proposed floor plans, with bedroom window sill heights and opening sizes. Other drawings are required only where that part of the building is being altered. Any wall, ceiling, or floor cavity opened up by the remodel must at least be filled with insulation.

Commercial projects need stamped drawings from a design professional. The county code (§15.040.090) requires every general contractor to keep a copy of the current International Building Code at their place of business. Work started before a permit is issued is subject to increased fees.

Local design standards

The county’s design values for residential work are:

Item	Butte-Silver Bow value
Frost depth	42 inches
Roof snow load	38 psf
Design wind speed	115 mph
Seismic design category	D
Air freezing index	2,500
Foundation rebar (minimum)	18 inches on center, both directions
Grade away from foundation	at least 6 inches in the first 10 feet

In the R-1 through R-4 zones, accessory buildings must be at least 3 feet from side and rear lot lines when there’s an alley behind, and 5 feet when there isn’t. Garage doors that open onto an alley need a 10-foot setback. Accessory buildings are capped at 16 feet with a gable or hip roof and 13 feet with a flat roof. See also do I need a permit for a garage.

Inspections

Schedule inspections at least 24 hours (one business day) ahead by calling (406) 497-6210. If no one answers, leave a message. Required inspections include:

• Rebar, before any concrete is poured, for footings, foundation walls, deck sonotubes, and retaining walls 4 feet or taller
• Foundation weatherproofing, before backfill
• Rough plumbing and mechanical, which must pass before the framing inspection
• Insulation and drywall
• Roofing: ice barrier and underlayment before covering, then a mandatory final roof inspection

The final building inspection requires finished grading and blower-door test results. Final plumbing and mechanical inspections are scheduled together with the final building inspection. A reinspection costs $75 an hour, with a one-hour minimum, when the work isn’t ready on arrival.

New buildings get a certificate of occupancy. Remodels, decks, additions, and plumbing or mechanical jobs get a certificate of completion instead.

Codes in effect

Butte-Silver Bow enforces the 2021 IBC, IRC, IEBC, IMC, IFGC, IECC, IFC, and International Swimming Pool and Spa Code, plus the 2021 Uniform Plumbing Code (Ordinance 2022-12). Montana’s 2024 code set takes effect statewide on September 26, 2026.