Williamson County, TN Accessory Structures: Shed & Carport Rules (2026)
Shed permit rules in Williamson County, TN, also referred to as storage shed, backyard shed, or accessory building regulations, set size limits, setbacks, and when a building permit is required.
Key Facts
- Lots ≤ 1 acre
- Shed must sit in the rear yard
- Setback (lots < 5 acres)
- 15 ft from side and rear lines
- Max size (≤ 1 acre)
- 75% of house or 2,000 sq ft, less
- Total accessory coverage cap
- 20% of the lot
- Front-yard option (5+ acres)
- 200 ft setback from front line
- Permit
- Zoning Certificate, Sec. 8.01, 5-day review
Summary
Williamson County sizes sheds and other accessory structures by lot area. On parcels of one acre or less, a shed must sit in the rear yard, set back at least 15 feet from the side and rear lines, and stay under 75 percent of the house's square footage or 2,000 square feet, whichever is less. Combined accessory coverage cannot exceed 20 percent of the lot.
(1) Accessory structures on lots with a lot an area of one acre or less shall: a) Only be permitted in the rear yard; b) Accessory structures, except Swimming Pools and all associated decking, shall be: i) Set back a minimum of 15 feet from the side property lines; and ii) Set back a minimum of 15 feet from the rear property line. (4) Maximum Size of Accessory Structure a) For parcels that are one acre or less in size, no single accessory structure shall be larger than 75 percent of the total square footage of the principal structure or 2,000 square feet, whichever is less. (5) In no instance shall accessory uses and structures cover more than 20 percent of the lot area.
Official source re-checked September 8, 2026: the cited page had not changed since it was quoted.
Full Breakdown
04(C) of the Zoning Ordinance tiers accessory structure rules by parcel size in the unincorporated county (Franklin, Brentwood, Spring Hill, Fairview and Nolennville run their own codes). On lots up to one acre, sheds are rear-yard only with 15-foot side and rear setbacks; on lots under five acres the same 15-foot setbacks apply without the rear-yard-only restriction; on lots of five acres or more, an owner can instead place the structure in the side yard at the principal-structure setback, or in the front yard if it sits back at least 200 feet from the front line and still meets the principal structure's side setback.
04(C)(4) sets the size cap: no single accessory structure on a one-acre-or-smaller lot may exceed 75 percent of the principal structure's square footage or 2,000 square feet, whichever is less; on larger parcels the cap uses 'whichever is greater' instead, and can be exceeded on five-plus-acre lots if the structure meets the principal-structure setback. 04(C)(5) caps total accessory coverage countywide at 20 percent of the lot regardless of parcel size. 01 requires an approved Zoning Certificate from the Planning Director, who must act within five business days after the application is complete; the certificate does not substitute for a building permit or certificate of occupancy where those are separately required.
Violations & Fines
Building or enlarging a shed without an approved Zoning Certificate is a violation under Section 22.03(A). The Codes Compliance Director, who enforces the Ordinance, investigates complaints filed with the Community Development Department and can revoke a noncompliant certificate under Section 22.06. Conviction is a misdemeanor carrying a fine of ten to fifty dollars under Section 22.07(A) and Tenn. Code Ann. § 13-7-111, with each day the violation continues counted as a separate offense; owners can appeal enforcement decisions to the Board of Zoning Appeals.
Frequently Asked Questions
Do I need a permit for a shed in Williamson County?
How large can a shed be on a one-acre lot?
Can I put a shed in my front yard?
What happens if I build a shed without a Zoning Certificate?
Sources & Official References
Other rules in Williamson County
How Williamson County compares: Shed Permit Requirements by City·Compare Williamson County to another location·View the Tennessee accessory structures overview
See something wrong?
Help us keep this page accurate. If you notice an error or outdated information, let us know.