Butte-Silver Bow Zoning & Land Use Guide
Official references and local checks
Use the official references below to identify the rules that apply to your address, then confirm parcel-specific requirements with the local authority before filing an application.
Official references
- Population:
- 34,751
- County:
- Silver Bow County
- State building code:
- Montana Building Codes Bureau administers code (based on 2021 IBC)(statewide default)
- State ADU law:
- Yes — Montana SB 528 (2023), codified at MCA 76-2-345, requires municipalities to adopt regulations allowing at least one accessory dwelling unit by right on a lot containing a single-family dwelling. SB 382 (2023, the Montana Land Use Planning Act) separately reorganized how larger Montana cities plan for housing.
- FEMA flood map:
- Search flood zones
- Planning department:
- Butte-Silver Bow Planning Department
- Municipal code:
- View code online
- Zoning map:
- View local zoning map
Before you apply
- Call the Butte-Silver Bow Planning Department: (406) 497-6250
- Search the municipal code for the chapter that covers your zoning district and proposed use.
- Use the local zoning map to look up your parcel's zoning designation before applying for a permit.
- Check FEMA flood zone for your parcel — flood-zone status changes setbacks, foundation requirements, and insurance.
- Check your HOA CC&Rs and recorded deed restrictions — they are common in Butte-Silver Bow and frequently restrict ADUs, fences, and exterior changes beyond what zoning allows.
Key Zoning Facts
Regulatory Layers That Apply in Butte-Silver Bow
Your property is subject to ALL of these regulatory layers. Each one can impose additional requirements beyond the others.
Federal
- FEMA flood mapping: check parcel-specific flood-zone status
- View FEMA Flood Map
State — Montana
- Building Code: Montana Building Code (based on 2021 IBC)
- State ADU Override: Yes (SB 528 and HB 211)
County — Silver Bow County
- Role: Property records, tax assessment, consolidated city-county government
City / Municipal
The municipality's zoning ordinance, building-code enforcement, and local permits form the primary local layer of land-use regulation for your property.
Overlay Districts
No overlay districts identified.
Private Restrictions
- Private covenants, deed restrictions, condominium rules, or association rules can impose requirements beyond zoning.
- Check HOA CC&Rs for additional restrictions.
Statewide Context (Montana)
Local data for Butte-Silver Bow is limited. The following state-level facts apply across Montana and are inherited by this page until city-specific details are verified.
- State Building Code
- Montana Building Codes Bureau administers code (based on 2021 IBC)
- State ADU Preemption
- Yes — state law overrides local rules
- Coastal Zone
- No
- Wildfire Zones
- Yes
ADU Rules in Butte-Silver Bow
- Max Size
- 900 sq ft
- Max Height
- 24 ft
- Rear Setback
- 5 ft
- Side Setback
- 5 ft
- Parking
- Verify with local jurisdiction
- Owner Occupancy
- Not required (per state law)
- Permit Timeline
- 3-5 weeks
Permit Costs & Timelines
Check Current Permit Fees & Timelines
Permit fees and review times can vary by project type, scope, valuation, and required approvals. Check the current schedule with the local permitting authority before filing.
Check current Butte-Silver Bow permit information →Official Sources
City-specific