ADU rules in Tennessee
Representative cities: Nashville, Memphis.
ADU permit rule
Permit requiredGenerally allowedcity authority
Fee basis
Valuation-based; Nashville residential fee is $5.00 per $1,000 of valuation.
Typical timeline
Nashville DADU review under Metro Code §17.16.250; varies by city.
Setback
Per local zoning (Nashville DADU setbacks under §17.16.250).
Area threshold
Nashville allows detached ADUs (DADUs) by right in most residential zones (Urban Services District).
Exempt if
None — an ADU always requires a building permit.
Go / no-go
allowed
Nashville streamlined DADU rules in 2025 (removed alley-access requirement, raised size limits); owner-occupancy is required. Other cities follow state ADU allowances.
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Frequently asked questions
Do I need a permit to build an ADU in Tennessee?
Per Tennessee rules, an ADU is "yes" for a permit and the authority is "city". Nashville streamlined DADU rules in 2025 (removed alley-access requirement, raised size limits); owner-occupancy is required. Other cities follow state ADU allowances. Always confirm with the issuing building department.
How big can an ADU be in Tennessee?
Area threshold: Nashville allows detached ADUs (DADUs) by right in most residential zones (Urban Services District).
What are the ADU setbacks in Tennessee?
Setback: Per local zoning (Nashville DADU setbacks under §17.16.250).
How much does an ADU permit cost in Tennessee?
Fee basis: Valuation-based; Nashville residential fee is $5.00 per $1,000 of valuation.
State-wide sources: TN State Fire Marshal — Residential Permits (2018 IRC + IECC) · Metro Nashville — Codes & Building Safety · Develop901 — Memphis & Shelby County Permits
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ADU build cost calculator
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Rental ROI and payback
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Financing comparison
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Does your ADU need a permit?
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