Chattanooga, TN Accessory Structures: ADU Permits (2026)

Accessory Dwelling Units in Chattanooga are regulated by the Chattanooga Zoning Ordinance (CZO), codified in City Code Part II, Chapter 38. ADUs are permitted as accessory uses in several residential districts (R-1, R-2, R-3, R-4) subject to dimensional standards. The ADU must be subordinate in size to the principal dwelling and may be attached or detached. Detached ADUs must meet accessory structure setbacks under CZO accessory structure provisions: typically 5 feet from side and rear lot lines, and behind the front building line of the principal dwelling. Maximum height for detached ADUs is generally limited to the underlying district's accessory structure height (typically 15 to 25 feet depending on roof form). Building permits are required from the Land Development Office, with separate plumbing, electrical, and mechanical permits. Form-based code areas adopted in 2024 (such as portions of the M-1 and downtown districts) allow ADUs by-right with form-based standards rather than dimensional zoning. Properties in Historic Zoning overlay districts (Fort Wood, M.L. King, St. Elmo, Ferger Place, Glenwood) require Chattanooga Historic Zoning Commission Certificate of Appropriateness before building permits issue.