Building permits in Williamson County, Tennessee
Of the 6 common home projects we have verified in Williamson County, 4 need a permit outright and 1 depends on size or scope. Click any project for the full rule, fee, and how to apply.
By Mario Bailey Last checked · 3 official sources
Verified against official sources- Project types verified
- 10
- in Williamson County
One thing Williamson County does not make you permit
Worth knowing before you call anyone. Most jurisdictions we cover require all of these.
- Roof Replacement Permit
No permit required for this work.
Williamson County Building Codes Department
- 1320 West Main Street, Suite 400, Franklin, TN 37064
- Phone: 615-790-5718
- Official permit page
- Permit portal
- Official fee schedule
Look up a permit in Williamson County
Williamson County permit records are public, and you can check a property's permit history online.
What needs a permit in Williamson County
Of the 6 common home projects we have verified in Williamson County, 4 need a permit outright and 1 depends on size or scope. Click any project for the full rule, fee, and how to apply.
| Project | Permit needed? | Threshold | Typical fee |
|---|---|---|---|
| Deck Permit | Permit required | Any size | ...general building permit valuation table: no fee for construction valued at $1,000... |
| Electrical Permit | Permit required | Any size | State-issued via the TN CORE system: a $5 issuing fee plus ampere-based inspection fees... |
| Fence Permit | Not confirmed | Not confirmed | ...permit bills under the Section B101 valuation table, no fee for work valued $1,000... |
| HVAC Permit | Permit required | Any size | Mechanical Permit Fee Schedule: $10.00 permit fee plus $10.00 for the first $1,000 of... |
| Patio Permit | Not confirmed | Not confirmed | billed under the Section B101 valuation table, $15 for the first $1,000 plus $5 per... |
| Plumbing Permit | Permit required | Any size | Plumbing Permit Fee Schedule: $10.00 for issuing each permit, plus $5.00 for water and... |
| Pool Permit | It depends | Swimming pools designed or able to hold water more than 30 inches deep in unincorporated Williamson County require a building permit; pools designed to hold 30 inches of water or less, temporary pools, above-ground pools with no permanent filter system or decking, and pools not left up year-round are exempt from the permit requirement. | billed under the Section B101 valuation table, for example $260 for the first $50,000 of... |
| Roof Replacement Permit | No permit needed | Exempt | No permit or fee |
| Shed Permit | Not confirmed | Not confirmed | ...needing a permit bills under the Section B101 valuation table, no fee at $1,000 or... |
| Solar Permit | Not confirmed | Not confirmed | ...mounting permit bills under the Section B101 valuation table starting at $15 for... |
Planning a project in Williamson County?
Hire it out
Sponsored
Licensed contractors usually pull the permit as part of the job. Comparing a few local quotes before you commit is the useful next step.
Compare local contractor quotes on Angi
Sponsored link. PermitNotebook may earn a fee if you request quotes through it. Partners never influence our permit data.
Planning several things at once? Check your whole project
Schedule an inspection in Williamson County
Permitted work is not finished until it passes inspection. The Building Codes inspections page lists required inspections and scheduling options.
Schedule or request a Williamson County inspection
When the portal will not take the date you need, the office still books by phone: 615-790-5718.
Checked . If the office has changed its process, report it.
Williamson County permit fees compared with nearby Tennessee localities
| Tennessee locality | Deck Permit | HVAC Permit | Electrical Permit |
|---|---|---|---|
| Williamson County | ...table: no fee for construction valued at $1,000 or... | Mechanical Permit Fee Schedule: $10.00 permit fee plus... | State-issued via the TN CORE system: a $5 issuing fee plus... |
| Memphis | ...TO DECKS, SPAS AND SIMILAR STRUCTURES $50.00, plus... | M-0 fee issuance cost per permit $20.00, M-3.1 fee for the... | E-0 fee issuance cost per permit $20.00, E3.1 minimum fee... |
| Nashville | Billed as a residential building permit at $5 per $1,000... | Flat minimum of $75 per gas/mechanical permit plus $32 per... | Flat minimum of $75 per permit with itemized add-on... |
Each cell is the opening clause of that Tennessee jurisdiction's own fee schedule; the full wording and source sit on each permit page.
Williamson County permit questions, answered from the data
- Do you need a permit in Williamson County?
- For most projects, yes. Of the 10 permit types we have verified for Williamson County, 4 always require a permit (for example a deck permit), 1 depends on size or scope (a pool permit, for instance), and 1 needs no permit at all in Williamson County. Each Williamson County permit type's page states the exact rule and its source.
- How much does a permit cost in Williamson County?
- Williamson County publishes a fee for 10 of the 10 permit types we cover, each quoted on its page from the jurisdiction's own schedule (linked on every page that carries one). Fees are set by Williamson County Building Codes Department; we do not estimate or mark them up.
- Where do you apply for a permit in Williamson County?
- Williamson County Building Codes Department issues permits in Williamson County, with an online portal for applications, plan uploads and status checks, and takes questions at 615-790-5718. The Williamson County official page and portal are linked in the office section above.
How the Williamson County pages were verified. 10 permit types, 9 distinct official sources, most recently checked . Every rule is read from Williamson County Building Codes Department or the applicable code and cited on its page; anything we could not confirm for Williamson County is marked rather than estimated. How we verify.
Permitting activity in Williamson County
In 2025, Williamson County authorized permits for 1,621 new residential housing units (1,286 single-family, 335 in multi-family buildings), valued at $1.2B , down from 1,994 the year before. That works out to about 6 permits per 1,000 residents. It is a useful gauge of how busy the local permit office is.
Source: U.S. Census Bureau, Building Permits Survey, 2025 annual data · population 272,061.