County Building Permits

Williamson County Building Permit Guide (Unincorporated Area)

How to apply for a building permit in unincorporated Williamson County, Tennessee. Permit authority, application steps, fees, and inspection requirements.

Tennessee Updated March 2026

Permit Authority

Applies to unincorporated Williamson County, not to incorporated cities that issue their own permits such as Franklin, Fairview, Nolensville, Brentwood, or Spring Hill.

Department
Williamson County Building Codes
Address
1320 West Main Street, Franklin, TN 37064
Phone
615-790-5718
Website
https://www.williamsoncounty-tn.gov/393/Permits

Online Permit Portal

Open Williamson County IDT Plan Review

Platform: IDT Electronic Plan Review System • Account required: Yes • Submission: In-person only

Additional resources:

Application Process

  1. Register or sign in to the Williamson County electronic plan review system.
  2. Select the project type and complete the online intake fields.
  3. Upload all required project documents from the county checklist.
  4. Submit the project and monitor email notices from info@idtplans.com for acceptance, denial, and review status.
  5. Pay fees online or at the Williamson County Administrative Complex, Suite 400.
  6. After permit issuance, schedule inspections as construction reaches each required phase.

Typical processing time: The county does not post a general plan review number on the pages reviewed, but the portal sends status notices at each review stage.

Source: Williamson County Building Codes

General Requirements

County page states building and other necessary permits may be completed through the county system; project types listed in the county IDT system include residential building permits, nonresidential building permits, signs, retaining walls, floodplain development, driveway permits, change of use or tenant requests, and related development submissions

Required Documents

  • Uploaded project documents per the county checklist
  • Plans and supporting materials vary by project type
Permit validity
Not clearly posted on the county permit and inspection pages reviewed
Building code
County adopted 2021 IBC, 2021 IRC excluding dwelling sprinkler section and electrical chapters, 2021 IPC, 2021 IMC, and 2018 IECC with 2009 tables effective September 30, 2024; state and SFMO approvals still apply for educational, daycare, and large assembly occupancies
Owner-builder
Not clearly posted on the pages reviewed
Contractor requirements
Not clearly summarized on the permit overview page reviewed; applicants should confirm Tennessee contractor licensing requirements with the county and the Tennessee Board for Licensing Contractors

Fees

Minimum permit fee
See county fee PDF; exact line items did not render in the browser tool on this run
Plan check fee
See county fee PDF
Permit fee formula
County publishes a complete current fees and requirements document rather than summarizing the formula on the main permit page
Reinspection fee
$50 per reinspection
Payment note
Checks payable to Williamson County Government; separate checks required for building permits and privilege taxes; county also allows online fee payment in the portal

Fees change. Verify current amounts at the official fee schedule.

Work That Does NOT Require a Permit

  • Residential roof repair or replacement does not require a permit or inspection when it is ordinary repair and does not involve structural work under adopted IRC Section R105.2.2
  • Standard permit exemptions in the county's adopted 2021 IRC and 2021 IBC

Important: Exemption from permit does not authorize work that violates adopted codes or other ordinances.

Inspections

How to Schedule

Scheduling deadline
No same-day cutoff or public inspection window posted on the page reviewed

Typical inspection sequence: Footings, foundation, slab, slab plumbing if applicable, framing, mechanical, plumbing, insulation, final building for certificate of occupancy, and storm water

Additional Resources

Information on this page was last verified: March 2026. Permit rules and fees change — confirm current requirements directly with the Williamson County Building Codes before applying.

Need help with your project?

Navigating permits in Unincorporated Williamson County can be complicated.

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Important: This page is an educational resource provided by jaspector.com. It is not legal advice, and it does not substitute for official guidance from the permit authority listed above. Permit requirements, fees, and processes change frequently. Always verify current requirements directly with the issuing department before beginning any construction project. Use of this page does not create an attorney-client relationship. Jaspector assumes no liability for any outcomes arising from reliance on this information.
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