County Building Permits
Big Horn County, MT - 2026 Building Permit Guide
How to apply for a building permit in unincorporated Big Horn County, Montana. Permit authority, application steps, fees, and inspection requirements.
Permit Authority
Unincorporated Big Horn County falls under the state Building Codes Program because the county has not adopted its own certified building code enforcement program. Private property owners in unincorporated areas must comply with state-level requirements. The county may have local zoning/subdivision rules, but building code enforcement is at the state level. Crow Reservation lands are excluded from county and state jurisdiction.
- Department
- Montana Building Codes Program
- Address
- 301 S. Park Avenue, 4th Floor, Helena MT 59601
- Phone
- (406) 841-2056
- BUILDINGCODES@MT.GOV
Online Permit Portal
Platform: EBIZ Montana (state online permit portal) • Account required: Yes • Submission: In-person only
Additional resources:
Application Process
- Review building code requirements and determine if permit is required
- Prepare complete application with construction plans/drawings meeting IBC 2021 standards
- Submit Building Permit/Plan Review Application and construction plans via EBIZ portal or mail to Montana Building Codes Program
- Await plan review comments (approximately 2-3 weeks processing time)
- Address any plan review comments and resubmit if required
- Pay permit fee upon approval
- Receive building permit and begin construction
- Schedule inspections with state building inspector at least 24 hours in advance
- Complete required inspections (foundation, framing, electrical, plumbing, mechanical, final)
- Receive Certificate of Occupancy upon final inspection approval
Typical processing time: Average 3 weeks for initial plan review if plans are complete; additional time may be required if revisions are needed
Source: Montana Building Codes Program
General Requirements
New construction of buildings, additions, alterations, repairs. State law exempts: farm/ranch buildings, mining buildings on mining property, residential buildings with fewer than 5 dwelling units (except transient), private garages and private storage buildings for owner's own use.
Required Documents
- Complete building permit/plan review application
- Construction plans and specifications prepared by licensed designer/engineer
- Site plan
- Structural calculations if required by code
- Electrical/plumbing/mechanical plans
- Permit validity
- Building permit is valid for the duration of construction but may expire if work does not commence within specified timeframe (typically 6-12 months, verify with state)
- Building code
- Montana 2021 International Building Code (IBC) and International Residential Code (IRC); state has approved adoption of 2024 codes planned for mid-2026
- Owner-builder
- Owner-builders may obtain permits for single-family dwellings on owner's own property; contact state Building Codes Program for specific requirements and restrictions
- Contractor requirements
- Electrical contractors must be licensed; plumbing contractors must be licensed; general contractors not required to be licensed at state level but check with county/local requirements
Fees
- Permit fee formula
- Typically valuation-based percentage of total project cost, plus separate electrical/plumbing/mechanical permit fees
- Payment note
- Payment required after plan approval and before permit issuance; accepted via EBIZ portal or mail. Contact (406) 841-2056 for current rates.
Work That Does NOT Require a Permit
- Farm or ranch buildings (not for human habitation or commercial use)
- Mining buildings on mining property
- Petroleum refineries and pulp/paper mills (except office/shop buildings)
- Single-family residential buildings (fewer than 5 units, not serving transient guests) - exemption applies only in areas without certified local code enforcement
- Private garages and storage buildings used solely for owner's own personal use (not commercial)
- Certain agricultural buildings on classified agricultural land (requires Affidavit of Agricultural Exemption and approval letter from Montana Department of Revenue)
- Minor repairs and maintenance
Inspections
How to Schedule
- ()
- Scheduling deadline
- 24 hours in advance
- Time windows
- Inspectors have 72 hours from notification to perform requested inspection
Typical inspection sequence: Foundation, framing (before insulation), electrical rough-in, plumbing rough-in, mechanical rough-in, insulation, drywall, final inspection
Additional Resources
- Building code: Montana 2021 International Building Code (IBC) and International Residential Code (IRC); state has approved adoption of 2024 codes planned for mid-2026
- Zoning information: View zoning info
- Montana Building Codes Program current codes
- Building Code FAQ
- License lookup guide: Montana Contractor License Requirements
- Contract template: Montana Homeowner-Contractor Agreement
- Montana hub: Montana Contractor License & Permit Hub
Information on this page was last verified: March 2026. Permit rules and fees change — confirm current requirements directly with the Montana Building Codes Program before applying.
Frequently Asked Questions
Big Horn County Building Permit FAQ
- Do I need a building permit in unincorporated Big Horn County, MT?
- New construction of buildings, additions, alterations, repairs. State law exempts: farm/ranch buildings, mining buildings on mining property, residential buildings with fewer than 5 dwelling units (except transient), private garages and private storage buildings for owner's own use.
- How much does a building permit cost in unincorporated Big Horn County, MT?
- Fees are calculated as: Typically valuation-based percentage of total project cost, plus separate electrical/plumbing/mechanical permit fees.
- How do I apply for a building permit in unincorporated Big Horn County, MT?
- 1. Review building code requirements and determine if permit is required 2. Prepare complete application with construction plans/drawings meeting IBC 2021 standards 3. Submit Building Permit/Plan Review Application and construction plans via EBIZ portal or mail to Montana Building Codes Program 4. Await plan review comments (approximately 2-3 weeks processing time) 5. Address any plan review comments and resubmit if required 6. Pay permit fee upon approval 7. Receive building permit and begin construction 8. Schedule inspections with state building inspector at least 24 hours in advance 9. Complete required inspections (foundation, framing, electrical, plumbing, mechanical, final) 10. Receive Certificate of Occupancy upon final inspection approval
- How long does it take to get a building permit in unincorporated Big Horn County, MT?
- Typical processing time is Average 3 weeks for initial plan review if plans are complete; additional time may be required if revisions are needed.
- What work is exempt from building permits in unincorporated Big Horn County, MT?
- The following work is generally exempt: Farm or ranch buildings (not for human habitation or commercial use); Mining buildings on mining property; Petroleum refineries and pulp/paper mills (except office/shop buildings); Single-family residential buildings (fewer than 5 units, not serving transient guests) - exemption applies only in areas without certified local code enforcement; Private garages and storage buildings used solely for owner's own personal use (not commercial); Certain agricultural buildings on classified agricultural land (requires Affidavit of Agricultural Exemption and approval letter from Montana Department of Revenue); Minor repairs and maintenance.
- How do I schedule a building inspection in unincorporated Big Horn County, MT?
- Inspections can be scheduled via: . 24 hours in advance.
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