County Building Permits
Mercer County, OH - 2026 Building Permit Guide
How to apply for a building permit in unincorporated Mercer County, Ohio. Permit authority, application steps, fees, and inspection requirements.
Permit Authority
Mercer County unincorporated territory under county zoning; county code exempts agricultural uses except certain platted subdivisions
- Department
- Mercer County Regional Planning Commission / Zoning Inspector
- Address
- 220 W Livingston St, Celina, OH 45822
- Phone
- (419) 586-3178
Application Process
Typical processing time: 30 days by code for zoning permit action
General Requirements
Required Documents
- owner name/address/phone, legal description, existing/proposed use, zoning district, scaled plans, building heights, parking/loading, access drives, driveway surface, dwelling unit count, sign info if applicable, flood zone info, detention basin info, and other items the inspector deems necessary
- Permit validity
- permit void if work not started within 1 year or completed within 2 years
- Building code
- county zoning code references land use controls only; no county building code adoption page found in the public materials reviewed
- Owner-builder
- application may be signed by the owner or the owner agent; no separate county contractor licensing rule found in the public zoning code
Fees
- Permit fee formula
- Set by Mercer County Commissioners under section 1145.10, but amounts not visible in the PDF text capture
Fees change. Verify current amounts at the official fee schedule.
Work That Does NOT Require a Permit
- Agricultural buildings and structures incident to agricultural use, except where the code specifically limits the exemption in platted subdivisions of 15 or more lots of 1 acre or less
- Temporary uses of public land are exempt from the temporary-use section
- Some temporary community activities for schools, churches, nonprofit community organizations, and clubs are exempt from the temporary-use rules
Inspections
How to Schedule
Typical inspection sequence: County zoning inspector reviews compliance, may issue stop-work orders, and may inspect properties and uses to enforce the zoning code
Additional Resources
- Building code: county zoning code references land use controls only; no county building code adoption page found in the public materials reviewed
- Zoning information: View zoning info
- Zoning code
- Permit application
- Subdivision variance form
- License lookup guide: Ohio Contractor License Requirements
- Contract template: Ohio Homeowner-Contractor Agreement
- Ohio hub: Ohio Contractor License & Permit Hub
Information on this page was last verified: March 2026. Permit rules and fees change — confirm current requirements directly with the Mercer County Regional Planning Commission / Zoning Inspector before applying.
Frequently Asked Questions
Mercer County Building Permit FAQ
- How much does a building permit cost in unincorporated Mercer County, OH?
- Fees are calculated as: Set by Mercer County Commissioners under section 1145.10, but amounts not visible in the PDF text capture.
- How long does it take to get a building permit in unincorporated Mercer County, OH?
- Typical processing time is 30 days by code for zoning permit action.
- What work is exempt from building permits in unincorporated Mercer County, OH?
- The following work is generally exempt: Agricultural buildings and structures incident to agricultural use, except where the code specifically limits the exemption in platted subdivisions of 15 or more lots of 1 acre or less; Temporary uses of public land are exempt from the temporary-use section; Some temporary community activities for schools, churches, nonprofit community organizations, and clubs are exempt from the temporary-use rules.
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