ADU Pass
Franklin
No County portion
Also in: Williamson County
ADU Pass helps homeowners in Franklin, No County, Tennessee navigate the permit paperwork for building an accessory dwelling unit. This area covers 2 ZIP codes.
Map
ADU details
ADU legality: yes
Cross-listing entry. Use canonical Williamson County / Franklin record for analysis.
Cost scenarios
| Scenario | Sq ft | Permit | Build | Total |
|---|---|---|---|---|
| minimum | 400 | $850 | $124,000 | $124,850 |
| midpoint | 700 | $1,500 | $217,000 | $218,500 |
| 1000 | 1,000 | $2,300 | $310,000 | $312,300 |
Fee breakdown
Viability (permitted uses)
- Long-term rental: yes Long-term rental of ADU permitted; Section 5.2.7.A owner-occupancy means one unit is owner-occupied, the other rentable.
- Short-term rental: with-restrictions Franklin regulates STRs separately from ADU permitting. Owner-occupancy requirement under Section 5.2.7.A constrains STR-of-the-ADU because the owner must occupy one of the two dwellings as a permanent residence.
- Office rental: no Section 5.2.7.A defines accessory dwelling as a self-contained dwelling; commercial office tenancy is not a permitted use.
- Home office: yes Home occupation permit available under residential districts.
- Studio / workshop: yes Personal artist/workshop use is a permitted accessory residential use.
- Agriculture: with-restrictions Limited residential gardening permitted; livestock varies by district. Civil-War-era estate parcels may have grandfathered agriculture use.
- Relative support: yes Multigenerational ADU explicitly permitted; 'family' definition in Chapter 23 governs owner-occupancy.
Utilities
- Water: City of Franklin Water Management Department (Harpeth River source) · 21d connect · $4,200
- Sewer: City of Franklin Water Reclamation Facility · 28d connect · $5,400
- Electric: Middle Tennessee Electric Membership Corporation (MTEMC) · 21d connect · $1,800
- Gas: Atmos Energy · 21d connect · $1,500
Property values & taxes
Construction timeline
Realistic total: best 9mo · typical 14mo · worst 22mo
Financing
Insurance impact
HOA prevalence & preemption
Franklin's affluent suburban subdivisions (Westhaven, McKay's Mill, Cool Springs, Berry Farms) are heavily HOA-governed. TN has no statute voiding HOA ADU bans. Westhaven and similar New Urbanist masterplans frequently DO permit accessory dwellings consistent with their pattern books, but each HOA must be checked.
Regulatory overlays (2)
- historic-district — Franklin Historic District (downtown core, NRHP-listed) + several Civil War battlefield protection overlays · +21d · +10% cost
Section 5.2.7.A design-standards rule (materials, color, roof matching principal structure) is reinforced by the historic-district overlay; ADUs in the district also need Historic Zoning Commission review. (map) - flood-zone — Harpeth River SFHA Zone AE through downtown / River Park; FEMA Map 47187C · +14d · +7% cost
Lowest-finished-floor elevation requirements apply along the Harpeth. (map)
Technical envelope (climate & building code)
Climate & energy code
Building code
Amendments:
- Amendment
- Amendment
Legal history (timeline)
Current ordinance: City of Franklin Zoning Ordinance, adopted 2025-12-01, last amended 2026-01-13
- 2026-01-13 — City of Franklin Zoning Ordinance Ord. 2025-25 effective date (city-ordinance)
Comprehensive zoning ordinance update adopted by Franklin Board of Mayor and Aldermen in 2025, effective 2026-01-13.
Effect: Operative ADU rules (Section 5.2.7.A) appear in this version: 50% footprint cap, owner-occupancy, parking under Section 10.1.6.
Federal (United States) — ADU-relevant rules and programs
Federal ADU law
The United States has no federal statute that directly regulates accessory dwelling unit entitlement or design. Land-use authority over ADUs resides with states and local governments under the traditional police power. Federal engagement is limited to financing (Fannie/Freddie/FHA/VA/USDA), flood insurance (FEMA/NFIP), and discretionary housing programs (HUD), which are recorded in sibling sections of this file.
Federal financing programs
Federal housing-finance agencies and GSEs set nationwide underwriting rules that govern whether an ADU can be financed, appraised, and counted toward mortgage qualifying income. The relevant actors are Fannie Mae, Freddie Mac, FHA (HUD), VA, and USDA Rural Development.
Federal tax credits
There is no ADU-specific federal tax credit. ADUs may incidentally qualify for existing federal energy-efficiency and clean-energy tax credits when the ADU construction includes qualifying measures.
Federal housing programs
HUD administers several discretionary programs that can fund ADU-related activity at the grantee's election, but none is an ADU-specific program.
ZIP Codes
- 37065
- 37068
Post Office
- 810 Oak Meadow Dr, 37064