What ADU can you build in your Miami-Dade County backyard?
Instant zoning report — see exactly what your zoning allows: permitted ADU types, size limits, setbacks, and lot requirements for your specific property.
Miami-Dade County ADU — Key Facts
- Maximum ADU size is 1,000 sq ft under Florida SB-48 — Miami follows the statewide baseline
- No owner-occupancy requirement under SB-48 — but Miami has historically imposed local rental and occupancy restrictions; verify current status
- Miami-Dade County HVHZ applies throughout — impact-resistant construction mandatory, adds 20–30% over inland Florida costs
- Miami has a unique Miami 21 zoning code — residential T3 zones (T3-L, T3-R, T3-O) are eligible for ADUs; confirm your transect zone
- Short-term rentals are heavily regulated by Miami — Miami Beach STR rules are separate and more restrictive
- Many Miami neighborhoods have deed restrictions (older covenants, historic designations) that restrict rental uses
- Construction $160,000–$350,000 (HVHZ + Miami labor premium); rental income $1,800–$3,500/month — highest range in Florida
Unincorporated Miami-Dade County Rules
*These rules apply if your address is NOT inside a specific city limit.
Miami-Dade County ADU Permit Process
- 1Confirm district eligibility with planning, then validate dimensions/parking and submit permit package.
Timeline: Miami 21 zoning review: 4–8 weeks. Building permit review: 5–8 weeks. Inspections: 10–14 weeks. Total: 6–10 months.
Find out what ADU you can build in your backyard
— and get a free Miami-Dade County ADU guide for your area.
Free report · No commitment · 60 seconds
Cities in Miami-Dade County
Aventura
Coral Gables
Cutler Bay
Doral
Hialeah
Homestead
Miami
Miami Beach
Miami Gardens
North Miami
Pinecrest
Unincorporated Miami Dade
Miami-Dade County ADU — Frequently Asked Questions
The most common questions from Miami-Dade County homeowners about ADU rules, permits, and costs.
What is Miami 21 and how does it affect my ADU eligibility?
Miami 21 is Miami's form-based zoning code that classifies all properties on a 'transect' scale from T1 (Natural) to T6 (Urban Core). Single-family ADUs are applicable in T3 zones (sub-transects T3-L, T3-R, T3-O). T4 and above are multi-family/commercial zones. Look up your parcel's transect at Miami's GIS portal or call Planning at (305) 416-1400 before designing.
How much does HVHZ add to ADU construction costs in Miami?
Miami-Dade County HVHZ requirements add approximately 20–30% over inland Florida ADU costs. This includes impact-rated windows ($300–$600/window), enhanced roof deck attachment (ring-shank nails, 8d spacing), hurricane straps at every rafter, and continuous load path requirements. A 600 sq ft ADU that might cost $120,000 inland costs $150,000–$180,000 in Miami. Budget accordingly.
Can I build an ADU in Miami's historic neighborhoods like Little Havana or Coconut Grove?
Yes, but with additional review requirements. Properties in Miami's designated historic districts require Historic Preservation review in addition to standard building permits. This can add 4–8 weeks to the approval process and may restrict exterior design elements. The City of Miami Historic Preservation Office (305-416-1408) can tell you if your property is in a historic district.
Are short-term rentals allowed with a Miami ADU?
City of Miami permits STRs with a Certificate of Use (COU) and registration. Miami has specific STR regulations including a $750+ annual fee, inspection requirements, and community meeting notification for some zones. Note that Miami Beach (a separate city) has much stricter STR restrictions — if your property is in Miami Beach, see the Miami Beach section. Miami's STR market is strong year-round given international tourism.
What is the realistic all-in cost for a Miami ADU project?
Budget $160,000–$350,000 for construction plus $13,000–$26,500 in permits and fees, plus $15,000–$40,000 for architectural/engineering drawings required for HVHZ compliance. All-in for a 600–1,000 sq ft detached ADU in Miami: $188,000–$416,500. Rental income of $1,800–$3,500/month creates a reasonable long-term ROI given Miami's rental demand, but this is a significant capital investment.
Read the Complete Miami ADU Guide
Five jurisdictions, HVHZ rules, Certificate of Use, real costs ($180K–$350K), and ROI analysis.
Florida ADU Laws 2026 — What SB-48 Actually Changed
Statewide rules on size limits, owner-occupancy, HOA overrides, and what local municipalities can still control.
Find out what ADU you can build in your backyard
— and get a free Miami-Dade County ADU guide for your area.
Free report · No commitment · 60 seconds