County Building Permits
Franklin County, MO - 2026 Building Permit Guide
How to apply for a building permit in unincorporated Franklin County, Missouri. Permit authority, application steps, fees, and inspection requirements.
Permit Authority
Applies to unincorporated Franklin County. Incorporated cities and villages in Franklin County run their own municipal routing unless a city or village expressly delegates work elsewhere.
- Department
- Franklin County Building Department
- Address
- 400 E Locust, Room 006, Union, MO 63084
- Phone
- (636) 583-6384
- building@franklinmo.gov
Online Permit Portal
Platform: County website intake page • Account required: No • Submission: In-person only
Additional resources:
Application Process
- Confirm whether the parcel is in unincorporated Franklin County and whether a separate Planning and Zoning filing is needed using the county permit page and Planning and Zoning routing.
- Contact the Building Department or use the county permit page to start the appropriate residential, outbuilding, manufactured home, or sewer permit request.
- Submit the application and supporting materials required for the project type. The county states it can provide inspection guidelines, code amendments, and fee lists on request.
- Coordinate any parallel county reviews that may apply, especially floodplain, planning and zoning, and on-site sewage where relevant.
- Wait for department review, respond to corrections, and receive permit issuance before starting work.
General Requirements
Franklin County states it has permitting requirements for construction and right-of-way use in unincorporated county areas; applicants must use the county permit page to determine whether a filing is needed.
- Building code
- County code amendments effective 04/23/2024 adopted for National Electric Code, Building Code, Fire Code, Residential One- and Two-Family Dwelling Code, Plumbing Code, Swimming Pool Code, and Mechanical Code. County also maintains a Flood Damage Prevention Ordinance and Unified Land-Use Regulations.
Fees
- Payment note
- Contact the Building Department directly for fee list.
Work That Does NOT Require a Permit
Contact the Franklin County Building Department to confirm whether your project requires a permit before starting work.
Inspections
How to Schedule
- (636) 583-6384 (phone)
Typical inspection sequence: County states inspection guidelines are available on request, but the sequence is not posted publicly.
Additional Resources
- Building code: County code amendments effective 04/23/2024 adopted for National Electric Code, Building Code, Fire Code, Residential One- and Two-Family Dwelling Code, Plumbing Code, Swimming Pool Code, and Mechanical Code. County also maintains a Flood Damage Prevention Ordinance and Unified Land-Use Regulations.
- Verify contractor license: Missouri Contractor License Lookup
- Zoning information: View zoning info
- Permits
- Building Department
- License lookup guide: Missouri Contractor License Requirements
- Contract template: Missouri Homeowner-Contractor Agreement
- Missouri hub: Missouri Contractor License & Permit Hub
Information on this page was last verified: March 2026. Permit rules and fees change — confirm current requirements directly with the Franklin County Building Department before applying.
Frequently Asked Questions
Franklin County Building Permit FAQ
- Do I need a building permit in unincorporated Franklin County, MO?
- Franklin County states it has permitting requirements for construction and right-of-way use in unincorporated county areas; applicants must use the county permit page to determine whether a filing is needed.
- How do I apply for a building permit in unincorporated Franklin County, MO?
- 1. Confirm whether the parcel is in unincorporated Franklin County and whether a separate Planning and Zoning filing is needed using the county permit page and Planning and Zoning routing. 2. Contact the Building Department or use the county permit page to start the appropriate residential, outbuilding, manufactured home, or sewer permit request. 3. Submit the application and supporting materials required for the project type. The county states it can provide inspection guidelines, code amendments, and fee lists on request. 4. Coordinate any parallel county reviews that may apply, especially floodplain, planning and zoning, and on-site sewage where relevant. 5. Wait for department review, respond to corrections, and receive permit issuance before starting work.
- How do I schedule a building inspection in unincorporated Franklin County, MO?
- Inspections can be scheduled via: (636) 583-6384.
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