ADU Construction Miami
ADU construction Miami homeowners can permit starts with the lot, not the floor plan: the zoning district, and which side of the Urban Development Boundary the property sits on. Gaven builds accessory dwelling units under one Florida CGC, site plan through final inspection.
What ADU construction covers here, and what it isn't
ADU construction Miami property owners bring us is one of three jobs: a new detached unit in the rear yard, a second unit built into the existing house, or an accessory structure converted into a permitted one. All three are full construction projects with their own permit track.
What a Gaven ADU build covers
What it isn't
What Miami-Dade actually allows, and what changes between attached and detached
Start where most of the internet is wrong. Florida has no statewide ADU mandate. Section 163.31771 of the Florida Statutes authorizes accessory dwelling unit ordinances: it says a local government mayadopt one, and that section's amendment history ends in 2020.Florida Statutes §163.31771
Bills to change may to shall have cleared the Florida Senate in consecutive sessions and died before enactment, and no later chapter law appears in that history. ADU construction is a local question, answered by your zoning district rather than by Tallahassee.
Six phases, one licensed team
Every Gaven ADU construction project runs the same six phases, in the same order, with one licensed team from the first site visit to the Certificate of Use. The sequence is what keeps a second dwelling on schedule when zoning, flood and building review all have to clear first.
Discovery
A free site visit, no trip fee. We pull the folio's zoning district, lot size, flood zone, Urban Development Boundary position and permit history, and tell you whether the lot can carry an accessory unit at all.
Design and scope
A site plan drawn by a design professional at the required scale, the unit sized inside the district's band, exterior finish and roof matched to the main house, association notice out. You get a fixed scope, not a number that climbs in the third change order.
Permitting
We pull the permit under our license. An ADU permit is not one review: zoning, building and flood run their own tracks, and the attached-versus-detached call decides whether the flood package is written as substantial improvement or as new construction.
Site work and rough trades
Foundation or slab for a detached unit; demolition and structural work for an attached one; then framing. Electrical, mechanical and plumbing run under our license, with the service sized for a second kitchen.
Finishes and installation
Kitchen, bathroom, flooring and fixtures inside. Exterior finish, glazing and roof outside, where the compatibility requirements become visible from the street.
Punch and closeout
Final inspections, the owner's Certificate of Use, and a written one-to-two-year labor warranty. One licensed team accountable for the result and for the renewal you file next year.
The license is the difference
ADU construction is a second dwelling unit: structure, a foundation or a changed load path, a full kitchen, a full bathroom, and a separate electrical and plumbing scope. Under Chapter 489 of the Florida Statutes a Certified General Contractor's scope is unlimited as to the type of work, the class that can own all of that on one permit. A Building Contractor is capped at three stories; a Residential Contractor at two.
That matters at the counter more than in the brochure. In Miami-Dade, Broward and Palm Beach County the building official confirms the contractor's certification before a permit issues.
Verify it before you sign. Our license is public on the state record, and so is our permit history: 500+ projects since 2015 · 37+ BuildZoom-verified permits.
The general contractor behind the ADU
ADU construction runs on the same license, the same crews and the same six phases as every other job we take. The full scope, the three counties we cover and the credentials behind them sit on our Miami general contracting work.
ADU construction questions
QDoes Florida require Miami-Dade to allow ADUs, or is that still a local decision?
Still local. Section 163.31771 of the Florida Statutes authorizes accessory dwelling unit ordinances rather than requiring them, and its amendment history ends in 2020. Bills to turn that permission into a requirement have passed the Florida Senate in consecutive sessions and died before enactment. Articles claiming a statewide mandate already applies describe a bill, not the statute.
QIs my lot eligible for an ADU in unincorporated Miami-Dade?
The baseline is one accessory unit per lot of at least 7,500 square feet, in an AU, EU or RU district inside the Urban Development Boundary. We check your folio at the first site visit.
QHow does flood review differ between an attached ADU and a detached ADU?
Under Chapter 11C of the county code an attached ADU is reviewed as a substantial improvement, while a detached ADU is reviewed as new construction. Those yardsticks can produce different requirements for the same square footage, which is why we settle it before drawings go out.
QHow much does ADU construction cost in Miami?
Scope decides it, not square footage. A detached unit carries its own foundation, its own utility runs and, in the High-Velocity Hurricane Zone, NOA-approved exterior assemblies; an attached unit adds demolition and load-path work instead. We quote ADU construction cost on site, after the zoning and flood determination, and quote it fixed.
QCan I rent out an ADU, and does it affect my homestead exemption?
You can, but only for periods of not less than one month, and neither the ADU nor the main house may be rented separately as a vacation rental. Establishing one can also change homestead exemption status, so ask the property appraiser first.
QCan an existing guesthouse be converted into an ADU?
Size is the first gate: a guesthouse larger than 800 square feet cannot be used as an ADU. The two are separate figures in the county code with different use restrictions, so conversion is a permit question, not a labelling one.
QDo the county's ADU rules apply if my house is inside an incorporated city?
No. The thresholds on this page come from the county code governing unincorporated Miami-Dade. Incorporated municipalities write their own rules, and in Broward ADUs are regulated municipally.
QDo I need a licensed contractor to build an ADU?
A homeowner can pull an owner-builder ADU permit and then carries the liability and the inspection sequence alone, on a project with structure, a full kitchen, a full bathroom and a separate MEP scope. An ADU contractor who holds the license puts one accountable party on all of it.
QAre you licensed and insured?
Yes. Gaven is a Florida Certified General Contractor, license CGC1524886, verifiable on the state record at MyFloridaLicense. General liability and workers' compensation certificates issue before any crew reaches the property, and our permit history is public on the BuildZoom record.
Find out whether your lot can carry an ADU
Every ADU construction project starts with a free site visit, no trip fee. We pull the zoning district, the flood zone and the permit history, and tell you whether the lot qualifies before you spend anything on drawings. One licensed team from the site plan to the Certificate of Use.
Last updated August 2026.