Franklin, TN Accessory Structures: Garage Conversions (2026)
Garage conversion rules in Franklin, TN, sometimes called garage-to-ADU or accessory living unit conversions, govern permits, ceiling height, egress, and parking replacement.
Key Facts
- Conversion allowed
- Existing accessory structure to ADU
- Key limit
- No increase in dimensional nonconformity
- Still applies
- One ADU/lot, 50% footprint cap
- Building codes
- Full compliance still required
Summary
Franklin, Tennessee lets homeowners convert an existing garage or other accessory structure into an accessory dwelling unit, as long as the conversion doesn't worsen any dimensional nonconformity on the lot.
Accessory dwellings may be converted from an existing accessory structure, as long as the conversion does not increase any dimensional nonconformity. 9. Parking shall be provided pursuant to Section 10.2, Minimum Parking.
10. Accessory dwellings shall be subject to all applicable building codes.
B. Accessory Structures Serving a Dwelling; or Serving a House Building Form in the HPO An accessory structure serving a dwelling, or serving a house building form in the HPO district, shall comply with the following:
1. Accessory structures of 200 square feet or greater shall comply with the principal building type standards for materials, material changes, roof elements, and colors. Accessory structures of less than 200 square feet are subject to Subsection 5.2.4, Minor Accessory Structures.
2. Any parking space within an accessory structure shall be at least ten feet by 20 feet of clear space per vehicle space.
3. Garages or carports in rear yards abutting an alley shall comply with the alley-loading garage standards of the applicable building type.
4. The accessory structure footprint shall not exceed 50 percent of the building footprint of the principal building.
C. Agricultural Uses See Paragraph 5.1.4.A, Agricultural Uses.
Full Breakdown
Franklin's 2026 Zoning Ordinance allows an existing accessory structure, including a detached garage, to be converted into an accessory dwelling unit under Section 5.2.7.A.8, provided the conversion does not increase any dimensional nonconformity already present on the lot. The converted unit must still meet the general ADU standards in Section 5.2.7.A: only one ADU per lot, a footprint no larger than 50 percent of the principal building, matching materials and roof elements with the principal building type, and compliance with all applicable building codes. Owner-occupancy of a single-family lot also still applies.
Violations & Fines
Converting a garage into living space without meeting the ADU and dimensional-nonconformity standards is a misdemeanor zoning violation under Section 22.5, enforced by the Department of Building and Neighborhood Services, with each day a separate offense.
Frequently Asked Questions
Can I convert my Franklin garage into an accessory dwelling unit?
Does a converted garage ADU skip the usual accessory-dwelling rules?
Sources & Official References
Other rules in Franklin
Compare Franklin 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.