How Chattanooga Handles Accessory Structures: A Practical Guide

Chattanooga maintains 81 local ordinances across all categories, and 9 of those deal specifically with accessory structures. Here is a breakdown of what the city actually requires, what is prohibited, and where Chattanooga falls on the strict-to-permissive spectrum compared to other cities.

Carport Rules

Chattanooga regulates carports as accessory structures under Chapter 38 (Zoning) of the City Code, with building permits administered under Chapter 10 (Buildings). The Land Development Office requires zoning clearance plus a building permit for both attached and detached carports. Setbacks are determined by the underlying residence district (R-1, R-2, R-3, R-4) and the structure type. Confirm specific dimensions with the Land Development Office at (423) 643-5891.

Key details: Zoning Code: Chapter 38 (Zoning). Building Code: Chapter 10 / IRC. Permit Required: Yes - building + zoning. Issuing Office: Land Development Office. Phone: (423) 643-5891.

Building a carport without a permit, in violation of setbacks, or in front of the front building line in a residential zone violates Chapter 38 and Chapter 10. The Land Development Office can issue stop-work orders, require removal or after-the-fact permitting, and refer cases to City Court for civil penalties.

Tiny Homes

Chattanooga's accessory dwelling unit (ADU) ordinance, adopted by City Council on May 31, 2022 and effective June 14, 2022, allows site-built ADUs up to 700 square feet on residential lots citywide. Tiny homes on wheels are explicitly excluded from the ADU definition. Tennessee has adopted the 2018 International Residential Code, which contains Appendix Q (Tiny Houses) defining a tiny house as a dwelling 400 square feet or less excluding lofts.

Key details: ADU Ordinance Effective: June 14, 2022. Max ADU Size: 700 sq ft. Tiny Homes on Wheels: Not permitted as ADU. State Code Reference: 2018 IRC Appendix Q. Tiny House Definition (IRC): ≤400 sq ft (excl. lofts).

Placing a tiny home on wheels as a primary or accessory residence, exceeding the 700 sq ft ADU cap, or building without permits violates Chapter 38 and Chapter 10. Code Enforcement can issue stop-work orders, require removal, and refer cases to City Court for civil penalties.

ADU Owner Occupancy

The Chattanooga Zoning Ordinance generally requires the principal dwelling on a lot with an ADU to be owner-occupied, treating the ADU as a subordinate accessory use. Both units cannot be rented to non-owners simultaneously without losing accessory use status. Tennessee has no statewide ADU-by-right preemption, leaving the requirement enforceable under Dillon Rule home rule authority.

Key details: Code Authority: City Code Ch. 38 (Zoning). Owner Must Occupy: Principal or ADU. Both Rented: Not allowed. TN Preemption: None (Dillon Rule). Verification: Affidavit + STR review.

Renting both the main dwelling and ADU to non-owners violates the Chattanooga Zoning Ordinance and can result in zoning enforcement notices, civil penalties, and required cessation of rental activity. STR permits are revoked when owner-occupancy lapses. Conversion to a duplex without rezoning is a continuing violation subject to daily penalties.

ADU Permits

Chattanooga allows Accessory Dwelling Units (ADUs) in specified residential zoning districts under the Chattanooga Zoning Ordinance (City Code Part II, Chapter 38). ADUs require building permits from the Department of Economic and Community Development (Land Development Office) and must meet lot size, setback, and height standards. The 2024 form-based code adoption created additional ADU pathways in downtown/midtown form districts.

Key details: Code Reference: City Code Ch. 38 (Zoning). Permit Office: Land Development Office. Eligible Districts: R-1, R-2, R-3, R-4 with conditions. Setbacks: 5 ft side/rear typical. Historic Overlay: CoA required (CHZC).

Building or occupying an ADU without permits violates City Code Part II Chapters 4 (Buildings) and 38 (Zoning), triggering stop-work orders, daily civil penalties, and potential demolition or restoration orders. Unpermitted electrical or plumbing work voids homeowner insurance and creates Tennessee state license violations. Historic overlay district violations carry separate Historic Zoning Commission enforcement.

ADU Rental Restrictions

Chattanooga ADUs may be rented for long-term residential use only when the owner occupies the other unit on the property. Short-Term Vacation Rentals (STVRs) are regulated under the Chattanooga Zoning Ordinance with Absentee and Homestay categories; only Homestay (owner-occupied) STVRs are allowed by-right in most residential R districts, restricting STVR use of ADUs to owner-occupied properties. Absentee STVR overlay districts apply elsewhere.

Key details: STVR Categories: Homestay (owner-occupied) / Absentee. Residential Zones: Homestay only by-right. ADU STVR: Homestay-only. Combined Tax: ~15%+ (state + county + local). Permit Renewal: Annual.

Operating an unpermitted STVR in Chattanooga carries civil penalties per City Code. Booking platforms (Airbnb, VRBO) face takedown requests for unregistered listings. Loss of owner-occupancy converts a Homestay permit to a violation, triggering revocation. Tax non-compliance creates separate Tennessee Department of Revenue enforcement. Both-units-rented ADU configurations violate the Zoning Ordinance accessory use standard.

ADU Impact Fees

Chattanooga does not impose a dedicated ADU impact fee. Standard building permit fees through the Land Development Office apply based on construction valuation. Tennessee American Water Company (water) and Chattanooga Wastewater (sewer) charge tap or capacity fees only if a new connection is required. Hamilton County does not levy school impact fees; sales tax-funded school construction applies generally.

Key details: ADU Impact Fee: None. School Impact Fee: None (Hamilton Co. funds via sales tax). Sewer Capacity Fee: Based on fixture count. Water Provider: Tennessee American Water. Stormwater: Based on impervious surface.

Building without paying required permit fees prevents issuance and triggers stop-work orders. Failure to pay sewer capacity fees prevents service connection. Unpermitted construction is assessed back-permit fees and may carry doubled penalties under the Chattanooga construction code.

Chattanooga is more permissive than most cities when it comes to adu impact fees. That said, there are still limits.

ADU Rules

Chattanooga's zoning code addresses accessory dwelling units. ADUs may be permitted in certain residential zones with conditions including size limits.

Key details: Zoning: Allowed in certain zones. Size: Must be subordinate to primary dwelling. Permit: Building permit required. Updates: City updating ADU zoning rules.

Building an unpermitted ADU results in fines and required compliance.

Garage Conversions

Converting a garage to living space in Chattanooga requires a building permit. The space must meet habitability standards and parking requirements.

Key details: Permit: Building permit required. Parking: Must maintain off-street parking. Habitability: Must meet building code. ADU: Separate dwelling triggers ADU rules.

Unpermitted conversions result in fines and required compliance.

Shed Rules

Chattanooga allows storage sheds as accessory structures in residential zones. Sheds must comply with setback requirements and larger sheds need building permits.

Key details: Small Sheds: Under ~120-200 sq ft may not need permit. Large Sheds: Building permit required. Placement: Rear or side yard only. Terrain: Drainage important on hilly lots.

Sheds violating setbacks may need to be relocated or removed.

The Bottom Line

Chattanooga'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 Chattanooga is broadly strict or permissive.

All of the above reflects Chattanooga'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.