ADU rules in Nashville

Detached ADUs (DADUs) are a 'Permitted with Conditions' (PC) use in AG/AR2a, RS, R, RM, RN1/RN2, RL1-RL3, OR20-OR40, and ORI districts per the 17.08.030 land use table, but only on lots inside the Urban Services District, inside a council-adopted DADU overlay in the General Services District, or where allowed by a Specific Plan; one DADU per lot and only with a single single-family principal structure.

Attached/internal ADUs exist only as 'accessory apartments': the home must be owner-occupied, the unit is capped at 25 percent of gross floor area, must connect internally (no street-facing entrance added for it), may not have separate utility meters, and the second unit must be occupied by a listed family member, so it cannot be rented to the general public.

DADUs also have height caps: eave height max 10 ft (single story) or 17 ft (two story), ridge line below the principal structure and max 27 ft from average finished grade; Chapter 17.38 controls height in RN1, RN2, RL1, RL2, RL3. No other accessory structure over 200 sq ft may share the lot with a DADU.

DADU: the DADU must be owned by the same person or entity as the principal structure, one of the two dwellings must be owner-occupied, and the DADU can never be divided from the property ownership. Accessory apartment: the single-family residence must be owner-occupied and the apartment occupied by a family member.

Access is tightly controlled: on lots without alley access, only one curb cut serves both dwellings; lots with alley access must take added access from the alley; a street-accessed driveway is limited to one, max 12 ft wide.

'Permitted with Conditions' (PC): administrative approval through Metro Codes with no public hearing, provided every 17.16.030.G standard is met, plus a restrictive covenant recorded before permit issuance. Metro Codes does not allow homeowner self-permits for building a DADU or converting a garage into one; a contractor must pull the permit.

No minimum lease term for long-term DADU rental was found in the ADU sections; long-term rental of a DADU is not prohibited (one of the two dwellings must be owner-occupied).