Rutherford County, TN Accessory Structures: ADU Rules (2026)

Section 1101.Q of the Rutherford County Zoning Resolution requires a minimum lot size of one (1) acre to add an ADU. Either the principal dwelling or the ADU must be occupied by the property owner as their principal and permanent residence for at least six (6) months out of the year. The ADU must be occupied by a family member as defined in Article II of the Zoning Resolution, or that family member's invited guest. Only one ADU is allowed per lot, and ADUs are not permitted in conjunction with a duplex or multi-family dwelling. The unit must maintain architectural compatibility with the primary residence, and any new separate outside entrance serving the ADU shall not be visible from the right-of-way. By-right approval requires meeting all dimensional and design standards; if a proposal does not meet those standards, the applicant must apply for a Special Exception with a public hearing before the Rutherford County Board of Zoning Appeals. Each approved property records a notarized Declaration of Covenant on file with the County agreeing to adhere to the ADU standards. Setbacks follow the underlying residential zoning district. Within Murfreesboro city limits, the City's 2025 Zoning Ordinance (Appendix A) defines an accessory apartment and applies its own standards — confirm with City Planning at (615) 893-6441. The county's general zoning authority derives from Tenn. Code Ann. Title 13, Chapter 7, Part 1.