ADU Rules in Miami, Florida

Miami is Florida's second-largest city and uses the Miami 21 Code — a form-based transect zoning code adopted in 2009. ADU eligibility is set by Miami 21 and any subsequent City Commission action, not by any statewide mandate.

Florida State ADU Framework

Florida has no statewide ADU mandate. Fla. Stat. §163.31771 ("Accessory dwelling units") authorizes — but does not require — local governments to adopt ADU ordinances in single-family zones after the local government finds a shortage of affordable rentals. Whether ADUs are permitted on a given Miami parcel depends on Miami 21 and the underlying transect zone.

Miami 21 Transect Zones (Single-Family Context)

Miami's transect zoning establishes a gradient from rural to urban:

• T3 (Sub-Urban): Single-family neighborhoods — divided into T3-R (Restricted), T3-L (Limited), and T3-O (Open).
• T4 (General Urban): Row houses, small apartments.
• T5 / T6: Higher-density mixed-use districts.

As of early 2025, ADUs were permitted in T3-L. The Planning, Zoning and Appeals Board (PZAB) endorsed expanding ADU allowances to T3-R and T3-O by a 7-0 vote in December 2024; final City Commission action was pending. Confirm current status with the Planning Department before designing an ADU.

Size, Setbacks, and Height

The specific size cap, setbacks, and height limits depend on the transect zone and any proposed ADU text amendment. Contact the City of Miami Planning Department at (305) 416-1400 for the current adopted standards on a specific parcel.

Flood Zone and Climate

Miami has significant flood exposure:

• Verify FEMA flood zone status — large portions of Miami are in Special Flood Hazard Areas.
• Florida Building Code flood provisions may require elevated foundations.
• The Miami-Dade County High Velocity Hurricane Zone (HVHZ) governs wind-resistant construction.
• Coastal Construction Control Line (CCCL) requirements apply seaward of the state's coastal building line.

Permit Process

1. Verify transect zone: Confirm via Miami's zoning GIS.
2. Confirm ADU eligibility: Check Miami 21 and any pending amendments with the Planning Department.
3. Check flood zone: FEMA Flood Map Service Center.
4. Submit plans: City of Miami Building Department (iBuild Miami portal).
5. Building permit and inspections: Florida Building Code + HVHZ standards.
6. Certificate of Occupancy: Required before occupancy.

Contact

City of Miami Planning Department 444 SW 2nd Avenue, Miami, FL 33130 Phone: (305) 416-1400 Website: miami.gov — Planning

Disclaimer: This page summarizes publicly available city information. Verify current Miami 21 standards and any pending ADU amendments directly with the City of Miami before starting any project.