Building Permits in Montana

We cover 15 cities in Montana. Select a city below to see local permit requirements.

15 Cities Covered

1,636 Permit Rules

IRC Building Code Base

Building Codes in Montana

Building permit requirements in Montana are enforced at the local level, each city and county building department sets its own rules, fees, and timelines. Most cities in Montana follow the 2021 IRC.

We cover 15 cities in Montana with 1,636 specific permit rules. That's real, locally researched data, not generic advice. Each city page shows exactly what triggers a permit, what's exempt, estimated fees, and how to apply.

The bottom line: don't assume your city follows the same rules as the one next door. A fence that's exempt in one town might need a full permit two miles away. Always check your specific city.

Permit Fees Across Montana

Across the 15 cities we cover in Montana, permit fees range from $25 – $4,000. The average sits around $121 – $492.

Fees vary a lot by city and project type. A simple fence permit might run you $50, while a full room addition could be $2,000+. Most cities calculate fees based on your estimated project value, typically 1–2% of construction cost. Check the specific city page for accurate numbers.

Common Permit Exemptions in Montana

These are the most common projects that don't require a permit across cities in Montana. Keep in mind, "exempt from a permit" doesn't mean "exempt from code." You still have to build to code even without a permit.

Windows and Doors: Exempt in 30 of our 15 covered cities

Fence: Exempt in 30 of our 15 covered cities

Tree Removal: Exempt in 15 of our 15 covered cities

Siding: Exempt in 15 of our 15 covered cities

Shed: Exempt in 15 of our 15 covered cities

Exemptions vary by city. Always verify with your local building department before starting work.