If you're planning a project in Hamilton County, Ohio, understanding the building permit process upfront can help you avoid delays, fines, and missed inspections. This guide covers Hamilton County building permit requirements, such as what needs a permit, how much it costs, and how to apply.
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What requires a building permit in Hamilton County?
The Hamilton County Building Department requires a permit for most construction-related work, including:
- New residential construction (single-family, duplex, 1-2-3 family dwellings) in unincorporated areas
- Additions or structural modifications to existing dwellings, e.g., building an addition, expanding rooms, or major remodels
- Detached accessory buildings (garages, workshops, barns, large sheds, etc.), unless they meet the specific small-structure exemption criteria
- Moving or setting up a manufactured/industrialized home or unit, the first installation or relocation of such units requires permit review
- Installation, renovation, or replacement of major systems (plumbing, electrical, HVAC/mechanical, septic, private water, wastewater, repairs that affect code-regulated systems), permits from the county’s appropriate trade-inspection agencies are required
- Demolition or rebuilding of existing structures (full or partial demolition) under building-code jurisdiction
- Any building work that must comply with zoning, floodplain, septic/onsite-sewage, stormwater, or public-works/utility requirements (e.g. if on private septic, or connecting to county sewer/water)
What doesn’t require a building permit?
Provided certain conditions are satisfied (size, setbacks, use, no utilities, no structural alteration), the following kinds of work may not require a building permit:
- Small residential accessory structures (e.g., sheds, small outbuildings) of 200 square feet or less, provided exterior walls are at least 6 ft from any other structure on the lot and at least 3 ft from all property lines.
- Minor maintenance or cosmetic repairs that do not involve structural changes, major system alterations (plumbing, electrical, HVAC), foundation work, or expansion, e.g., painting, interior cosmetic updates (assuming no code-regulated changes)
If you build an accessory structure <200 sq ft that meets the setback/distancing criteria, you still may need a zoning certificate (or zoning compliance), but may avoid the full building permit process under certain conditions.
Hamilton County building permit cost
Hamilton County permit fees are typically based on square footage or valuation, plus any required inspections or plan reviews.
Residential fees
Commercial fees
To get more information on other building permit fees, refer to the Hamilton County Building Fee Calculation page.
Hamilton County trade permits
Plumbing permits
Plumbing permits are required in Hamilton County for all new installations or modifications to water, sewer, or gas systems.
Electrical permits
Electrical permits cover wiring, service upgrades, and system installations.
HVAC permits
Permits are required for installing or modifying HVAC systems, including ductwork and ventilation.
Roofing, fence, and special permits
Accessory permits cover a wide range of outdoor and structural work.
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How to get a building permit in Hamilton County
Step 1: Prepare your plans and application
First, check which AHJ oversees your project. You may need to go through the City of Cincinnati rather than Hamilton County.
Before applying, you must gather the required documentation. The county accepts residential and commercial applications in person, by mail, or online (for limited permit types).
You’ll need:
- Completed Hamilton County, OH building permit application
- Site plan showing dimensions, setbacks, utilities, driveways, and proposed work
- Construction drawings (must be sealed/stamped when required by Ohio law)
- Contractor registration or licenses (if applicable)
- Estimated construction cost and project description
- Digital PDF set of all plans, reports, and specifications (required for scanning)
Plan set requirements:
- Residential projects typically require 3 sets of plans
- Commercial projects typically require 4 sets of plans
- All submissions must also include a digital PDF of all materials
- Plans requiring professional certification must be sealed by Ohio-licensed architects/engineers
For questions on plan requirements, contact Buildings & Inspections at (513) 946-4550.
Step 2: Submit your application
Hamilton County accepts applications in three ways:
Option A – Submit in person or by mail
Submit at:
Planning & Development Department
- Address: 138 East Court Street, 8th Floor, Cincinnati, OH 45202
- Hours: Monday–Friday, 7:30 AM – 4:00 PM
Option B – Submit online via ezTrak (only for certain permit types)
The following permits can be fully completed online:
- Residential replacement mechanical permits
- Commercial mechanical permits
- Commercial sign permits
- Residential swimming pool permits
- Residential deck permits
Start online in the Hamilton County permit portal.
Application structure options (Commercial Projects):
Hamilton County allows multiple submission formats:
- Coordinated Application (non-separated): Submit all associated applications together (mechanical, fire alarm, water availability, earthwork, storm drainage, etc.)
- Associated Applications: Submit different components (HVAC, gas line, fire systems, hoods, underground fire line, etc.) separately, but all approvals must be completed before the permit is issued
- Partial / Phased Permits: Footings & foundation (F&F), shell, and interior build-out phases may be requested
Step 3: Plan review
Once your application is submitted and assigned a Building Permit Number, it enters the routing and review phase.
County-coordinated routing includes:
- Hamilton County Planning & Development
- Building & Inspections Division
- Storm Water & Infrastructure (stormwater, drainage, floodplain)
- Hamilton County Soil & Water Conservation District
- Erosion control, slope, soils
- Metropolitan Sewer District (MSDGC)
- Sewer availability, connection approval
- Greater Cincinnati Water Works (GCWW)
- Water availability review
Step 4: Pay permit fees and receive approval
After all required agencies approve the plans, Hamilton County building department officials will calculate permit fees. You will receive a fee invoice via ezTrak or at the permit counter
Once payment is made, your building permit will be officially issued. Permits must be posted on-site during all construction activities.
Step 5: Start work and schedule inspections
Once the permit is issued, you may begin construction. Use your Building Permit Number to schedule inspections.
Typical required inspections include:
- Footings & foundations
- Framing
- HVAC, plumbing, and electrical trade inspections (performed by appropriate agencies)
- Fire system inspections (if applicable)
- Final building inspection
You can track all inspection requirements and the status of approvals using ezTrak Online Services.
Hamilton County permitting resources
- Hamilton County Building Department
- Address: 138 East Court Street, 8th Floor, Cincinnati, Ohio, 45202
- Phone: (513) 946-4550
- Hours: Monday to Friday, 7:30 AM – 4:00 PM
- ezTrak Online Services
- Building permit guides
- Applications and forms
- Building Fee Calculation
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