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Building Permits in Montana

Montana statewide rules

These state rules apply everywhere in the state. Cities and counties may add stricter local rules — open your city below.

Local changes allowed
Limited source: bsd.dli.mt.gov
Issued by
Building Codes Bureau source: bsd.dli.mt.gov
Building code
2024 IRC, effective September 26, 2026 source: bsd.dli.mt.gov

Shed

Exempt from a permit
Private garages and private storage buildings used for the owner's own use (not part of a commercial enterprise or business) are exempt from the need to obtain a state building permit, in areas outside cities certified to issue their own permits. source: bsd.dli.mt.gov

Garage

Exempt from a permit
Private garages and private storage buildings used for the owner's own use (not part of a commercial enterprise or business) are exempt from the need to obtain a state building permit, in areas outside cities certified to issue their own permits. source: bsd.dli.mt.gov

Home Addition

Fee
generally one to two percent (1% - 2%) of the building valuation source: bsd.dli.mt.gov
Permit required
Yes source: bsd.dli.mt.gov

Cities

Permit Categories

Permit guides