Accessory Structures in Williamson County, TN (2026)
2 county-level rules, plus city-specific rules for 1 city in Williamson County, Tennessee.
Verified from official government sources
ADU Rules
Williamson County allows one accessory dwelling unit per parcel, built as an interior apartment or as a separate or converted accessory structure such as a garage, carriage house or stable. It is capped at 750 square feet or 25 percent of the principal house's size, whichever is greater, and can never exceed 75 percent of the house.
Williamson County Accessory Dwelling Unit Standards
Some RestrictionsWilliamson County, TN, Zoning Ordinance § 11.04(D)(1)
(1) Accessory Dwelling Units a) Accessory dwelling units may be constructed within an existing dwelling unit (interior apartment) or as a separate or converted accessory structure (e.g., converted garage, carriage house, or stable). b) Only one accessory dwelling unit, regardless of the number of principal dwellings located on a single parcel, may be permitted. c) Accessory dwellings shall be l...
Shed & Carport Rules
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.
Williamson County Shed and Accessory Structure Rules
Some RestrictionsWilliamson County, TN, Zoning Ordinance § 11.04(C)
(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 ...
Accessory Structures by City in Williamson County
1 cities in Williamson County have their own accessory structures rules. Each link goes to that city's dedicated page with code citations.
All Williamson County ordinances
See every category we cover for Williamson County: parking, noise, fences, fires, animals, pools, and more.
Williamson County Ordinance Hub →