ADU Pass
Chattanooga
Hamilton County portion
Also in: Marion County · No County
ADU Pass helps homeowners in Chattanooga, Hamilton County, Tennessee navigate the permit paperwork for building an accessory dwelling unit. This area covers 14 ZIP codes.
Map
ADU details
ADU legality: unclear
Tennessee leaves ADU regulation to local municipalities under home-rule or Dillon-rule authority. Chattanooga permits ADUs subject to local conditions per its zoning ordinance.
Cost scenarios
| Scenario | Sq ft | Permit | Build | Total |
|---|---|---|---|---|
| minimum | 150 | $1,600 | $34,500 | $36,100 |
| 600 | 600 | $1,600 | $138,000 | $139,600 |
| midpoint | 525 | $1,600 | $120,750 | $122,350 |
| maximum | 900 | $1,600 | $207,000 | $208,600 |
Fee breakdown
Viability (permitted uses)
- Long-term rental: yes Long-term rental of ADU generally permitted; landlord-tenant law and any city rental-registration ordinance apply.
- Short-term rental: with-restrictions STR rules vary by city. Chattanooga regulates STRs separately from ADU permitting; check local STR ordinance and HOA covenants.
- Office rental: with-restrictions Detached office rental requires home occupation permit or rezoning.
- Home office: yes Home occupation permitted with restrictions on signage and customer traffic.
- Studio / workshop: yes Personal artist studio is a permitted accessory use.
- Agriculture: with-restrictions Limited urban agriculture permitted in residential zones; livestock varies by district.
- Relative support: yes Family-occupancy ADU explicitly permitted in single-family zones.
Utilities
- Water: Chattanooga Water Utility · 30d connect · $4,500
- Sewer: Chattanooga Sewer / Wastewater · 30d connect · $5,500
- Electric: Chattanooga Electric Utility · 21d connect · $1,800
- Gas: Chattanooga Gas Utility · 30d connect · $1,500
Property values & taxes
Construction timeline
Realistic total: best 7mo · typical 10mo · worst 16mo
Financing
Insurance impact
HOA prevalence & preemption
Tennessee has no statewide statute that voids HOA bans on ADUs. Common-interest communities in Tennessee are governed primarily by the Tennessee Condominium Act of 2008 (T.C.A. §§66-27-201 to 66-27-603) for condominiums, by Tennessee's Horizontal Property Act (T.C.A. §66-27-101 et seq.) for older horizontal-property regimes, and by general nonprofit corporation law for HOA-style planned communities. Restrictive covenants in declarations and bylaws — including those prohibiting accessory structures or secondary kitchens — remain enforceable per their terms.
Technical envelope (climate & building code)
Climate & energy code
Building code
Amendments:
- Amendment
- Amendment
Legal history (timeline)
Current ordinance: City of Chattanooga Municipal Code — Accessory Dwelling Units, adopted 2020-01-01, last amended 2024-04-01
- 2024-01-01 — City of Chattanooga ADU code refresh (city-ordinance)
Conforming local-code amendments aligning with current Tennessee accessory-dwelling framework.
Effect: Codified permissive ADU standards consistent with state law and local zoning.
Hamilton County — county ADU rules and overlays
County ADU ordinance
Hamilton County, TN (373,000 residents including Chattanooga - distinct from Hamilton County, OH and Hamilton County, IN) operates a county zoning ordinance for unincorporated territory. The City of Chattanooga and other incorporated municipalities (East Ridge, Red Bank, Soddy-Daisy, Signal Mountain, Lookout Mountain, Collegedale) set their own rules.
State-floor overlay: No TN statewide ADU preemption.
County regulatory overlays
Hamilton County administers flood-hazard, and (where mapped) coastal, wildland-fire, historic, and airport overlays that shape ADU project feasibility. The most consistent overlay across the county is FEMA NFIP floodplain regulation; other overlays apply to specific geographies inside the county.
- FEMA NFIP Special Flood Hazard Areas in Hamilton County — A new ADU in a mapped SFHA must be elevated to or above the Base Flood Elevation; cost impact on the project is often material.
- Historic districts and individually-listed historic resources
County permitting (unincorporated parcels)
Hamilton County issues building permits for parcels in unincorporated territory through its development services / planning department, with separate review tracks for zoning conformance, building-code compliance, on-site sewage where applicable, floodplain compliance, and addressing. Inside incorporated municipalities, city departments handle their own permits; the county's authority is geographically limited to unincorporated territory. An ADU permit application is typically processed as a residential building permit with a zoning verification step against the county's ordinance for the parcel's zoning district.
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
- 37402
- 37403
- 37404
- 37406
- 37407
- 37408
- 37409
- 37410
- 37411
- 37412
- 37415
- 37416
- 37421
- 37450
Post Office
- 1101 W 40th St, 37409
- 1510 Maxwell Rd, 37412
- 2200 Amnicola Hwy, 37406
- 3317 Dayton Blvd, 37415
- 4420 Oakwood Dr, 37416
- 511 S Hawthorne St, 37404
- 711 Eastgate Loop, 37411
- 910 Georgia Ave, 37402