Franklin's Accessory Structures: The Rules That Matter

Every city handles accessory structures a little differently. In Franklin, Tennessee, there are 4 distinct rules that residents and property owners should be aware of. Some are stricter than what neighboring cities enforce, and others are more relaxed. Here is what you need to know.

Shed & Carport Rules

Franklin caps a shed, workshop or greenhouse at 200 square feet as a "minor accessory structure" under Zoning Ordinance § 5.2.4; go over that and it must match the house's exterior materials, roof elements and colors under § 5.2.7.B. Every accessory structure is capped at 50 percent of the principal building's footprint and must sit outside recorded easements.

Key details: Minor accessory structure cap: 200 sq ft footprint. Building permit: exempt under 200 sq ft (IRC amendment). Zoning approval: still required regardless of size. 200 sq ft or larger: must match principal building materials/roof/colors. Footprint limit: 50% of principal building footprint.

Building or maintaining an accessory structure that violates the Zoning Ordinance is a misdemeanor under § 22.5, punishable by a fine under the general penalty clauses of Title 12 of the Municipal Code, with each day of continuing violation a separate offense. Starting construction of an accessory building without the building permit required by Title 12 (for structures 200 square feet or larger) is separately unlawful under § 22.2. The City Attorney or an affected neighboring property owner may also seek an injunction or other court remedy under § 22.6.

ADU Owner Occupancy

Franklin, Tennessee requires the owner of a single-family lot to permanently occupy the property before an accessory dwelling unit is allowed on that lot under the 2026 zoning ordinance.

Key details: Max ADUs per lot: One accessory dwelling unit. Owner-occupancy: Owner must permanently occupy lot. Footprint cap: 50% of principal building footprint. Enforcing agency: Dept. of Building & Neighborhood Services.

Violating any zoning ordinance provision, including the ADU owner-occupancy requirement, is a misdemeanor enforced by the Department of Building and Neighborhood Services; each day of continued violation is a separate offense.

Garage Conversions

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.

Key details: 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.

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.

ADU Rules

Detached accessory dwelling units in Franklin may proceed to building-permit stage, but the owner must sign a parkland impact fee contract and pay the fee once it's executed.

Key details: Permit stage: detached ADUs cleared to proceed. Required: parkland impact fee contract. Payment trigger: due once agreement is executed. Fee amount: $5,268 per dwelling unit (§25-405).

Pulling a building permit for a detached ADU without executing the required parkland impact fee contract and payment violates Municipal Code § 25-406 and can delay or block permit issuance.

The Bottom Line

Franklin's accessory structures rules are a mixed bag. Some areas are strict, others are relaxed, and the details matter. The best approach is to check the specific rule that applies to your situation rather than assuming Franklin is broadly strict or permissive.

All of the above reflects Franklin's municipal code as of our last review. If you need specifics on fines, exemptions, or filing requirements, the detailed ordinance pages linked above have the full breakdown.