Accessory Structures in Nashville, TN: What Residents Actually Need to Know

If you live in Nashville or are thinking about moving there, accessory structures are one of those things you probably won't think about until they affect you directly. Nashville has 9 specific rules on the books covering different aspects of accessory structures, and some of them might surprise you.

Tiny Homes

Metro Nashville allows tiny homes only as Detached Accessory Dwelling Units (DADUs) on a permanent foundation, capped at 700 sq ft (or 850 sq ft on lots 10,000+ sf), and only in the Urban Services District, DADU overlays, or qualifying UDO/SP plans. Tiny houses on wheels are not permitted as full-time residences.

Key details: Allowed Areas: Urban Services District, DADU overlay, UDO/SP w/ DADU. Max Size: 700 sf (<10,000 sf lot); 850 sf (≥10,000 sf). Max Height: 27 ft ridge; eave 10 ft (1-story) / 17 ft (2-story). Setbacks (≤850 sf): 1/2 side (≥3 ft); rear ≥3 ft (10 ft alley). Tiny House Code: IRC Appendix Q (≤400 sf) under 2018 IRC.

Living in a tiny house on wheels on a Metro residential lot, exceeding the 700/850 sq ft DADU cap, building without a permit, or violating setbacks, owner-occupancy, or short-term-rental rules is enforceable by Metro Codes Property Standards. Remedies include stop-work orders, removal orders, civil fines, and revocation of any related short-term-rental permit.

This is not one of those rules that cities tend to ignore. Nashville actively enforces its tiny homes requirements.

Carport Rules

Metro Nashville treats carports as accessory structures regulated by Title 17 of the Metro Code, with reduced setbacks for rear-yard carports of 700 sq ft or less, height capped at 16 ft on lots under 40,000 sq ft, and a building permit required from the Department of Codes and Building Safety.

Key details: Code: Title 17 §§17.12.040, 17.12.050, 17.12.060. Side Setback (≤700 sf, rear): 1/2 district min, ≥3 ft. Rear Setback: 3 ft (10 ft if facing alley). Height Cap: 16 ft / 1 story (lots <40,000 sf). Footprint Cap: 700 sf or 50% of principal, max 2,500 sf.

Building a carport without a permit, exceeding setbacks or height, or placing it in a front yard or side yard without full setbacks is enforceable by Metro Codes Property Standards. Penalties include stop-work orders, removal orders, and civil fines under the Metro Code, and unpermitted structures often surface during resale inspections.

ADU Impact Fees

Nashville does not impose a dedicated DADU impact fee. Standard building permit fees through Metro Codes apply based on construction valuation. Metro Water Services may charge tap fees if a new water/sewer connection is required, and Metro Schools impact fees do not apply to single accessory units. Stormwater fees apply based on impervious surface added.

Key details: DADU Impact Fee: None. Permit Fee Basis: $5.50 per $1,000 valuation + base. Water Tap Fee: Only if new connection needed. Stormwater Fee: Based on impervious surface added. Property Tax: Reassessed after construction.

Building without paying required permit fees prevents issuance and causes stop-work orders. Failure to obtain water/sewer connections for plumbing fixtures violates Metro Water Services rules. Unpermitted construction is assessed back-permit fees and double penalties.

The rules around adu impact fees in Nashville lean permissive, but that does not mean anything goes.

ADU Rental Restrictions

Nashville DADUs may be rented for long-term residential use only when the owner occupies the other unit on the property. Short-Term Rentals are regulated under Metro Code Section 6.28, which distinguishes Owner-Occupied (Type 1) from Non-Owner-Occupied (Type 2) STR permits. Only Type 1 STR permits are allowed in residential zones, restricting DADU STR use to owner-occupied properties.

Key details: STR Code: Metro Code Chapter 6.28. Type 2 in Residential: Prohibited (new permits). DADU STR: Type 1 (Owner-Occupied) only. Permit Fee: $313 annually. Combined Tax: ~14.75% on STR revenue.

Operating an unpermitted STR in Nashville carries fines up to $50 per day. Booking platforms (Airbnb, VRBO) face penalties for listing unregistered units. Loss of owner-occupancy converts a Type 1 permit to a violation, triggering revocation. Tax non-compliance creates separate Tennessee Department of Revenue enforcement. Both-units-rented DADU configurations violate Code 17.16.250.

Compared to other cities, Nashville takes a harder line on adu rental restrictions. The enforcement and penalty structure reflects that.

ADU Permits

Nashville allows Detached Accessory Dwelling Units (DADUs) in specified residential districts under Metro Code Title 17 (Zoning Code). DADUs require building permits from Metro Codes and Building Safety and must comply with Section 17.16.250 standards including lot size, setbacks, and height. Some districts require Specific Plan or zoning change approval.

Key details: Code Section: Metro Code 17.16.250. Eligible Districts: R-A series (-A suffix zones). Max Size: 700 sq ft or 25% of main. Max Height: 16 ft or main height. Setbacks: 5 ft side and rear typical.

Building or occupying a DADU without permits violates Metro Code Title 16 (Building Code) and Title 17, triggering stop-work orders, daily fines, and required demolition or restoration. Unpermitted electrical or plumbing work voids homeowner insurance. Historic district violations carry separate Historic Zoning Commission enforcement.

ADU Owner Occupancy

Nashville Metro Code Section 17.16.250 requires that either the principal dwelling or the DADU be occupied by the property owner as their primary residence. Both units cannot be rented to non-owners simultaneously. Owner-occupancy must be documented and is verified during STR registration and code complaint investigations. Tennessee state law has not preempted this requirement.

Key details: Code Section: Metro Code 17.16.250(D). Requirement: Owner must occupy one unit. Both Rented: Not allowed. Verification: Affidavit + STR review. Daily Fine: Up to $50 per day.

Renting both the main house and DADU to non-owners violates Metro Code 17.16.250 and can result in fines, loss of certificate of occupancy, and required cessation of rental activity. STR permits are revoked when owner-occupancy lapses. Code violations carry daily fines of up to $50 per day per violation under Metro Code.

This is one of the stricter rules in Nashville's municipal code. If you are unsure whether your situation complies, it is worth checking with the city before proceeding.

Shed Rules

Sheds and carports 10 ft × 10 ft (100 sq ft) or larger require a building permit in Nashville. Smaller sheds are exempt. Sheds must comply with zoning setbacks and may not be used as living space.

Key details: Permit Threshold: 100 sq ft (10' × 10') or larger requires a permit. Under 100 sq ft: No permit required; setbacks still apply. Rear Setback: Minimum 3 feet (10 ft if door opens to alley). Living Space: Prohibited — no bedrooms, kitchens, or dwelling use. Electrical: Separate electrical permit required for any wiring.

Building without permit (for 100+ sq ft): stop-work order + retroactive permit required.

The rules around shed rules in Nashville lean permissive, but that does not mean anything goes.

Garage Conversions

Converting an attached garage or detached garage to living space in Nashville requires a building permit. Converting a detached garage to a DADU requires a contractor permit and compliance with all DADU standards.

Key details: Permit Required: Yes — building permit before any conversion begins. Self-Permitting: NOT allowed for garage-to-DADU conversions; contractor must pull permit. Habitable Space Standards: Must meet IRC ceiling height, egress, insulation, HVAC requirements. DADU Conversion: Max 700–850 sq ft; DADU rules apply. Historic Overlay: Recorded covenant required; STR use prohibited.

Unpermitted conversion: stop-work order + retroactive permit + possible removal requirement.

ADU Rules

Nashville streamlined DADU (Detached Accessory Dwelling Unit) rules significantly in 2025. DADUs are permitted by right in most residential zones within the Urban Services District. Size limits were raised, and the alley access requirement was removed.

Key details: Code: BL2025-1007; Metro Zoning Code Title 17. Status: Permitted by right in most USD residential zones. Size Limit: Up to 700 sq ft standard; 850 sq ft on lots >10,000 sq ft. Setbacks: 5-ft side/rear; 10-ft from primary dwelling. Alley Requirement: Removed (BL2025-1007).

Building without permit: stop-work order. STR rental of DADU violates §6.28.030 and Zoning Code.

Nashville is more permissive than most cities when it comes to adu rules. That said, there are still limits.

The Bottom Line

Nashville'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 Nashville is broadly strict or permissive.

This guide is based on Nashville's current municipal code. Local rules can and do change, so check the individual ordinance pages for the latest details, penalties, and FAQs.