ADU Permits in Florida: Process, Costs & Timelines

Permitting is where ADU projects are won or lost. The construction itself is straightforward for an experienced builder; the approval path — zoning verification, engineered drawings, plan review, revisions, inspections — is where unprepared projects stall for months. Here is what the ADU permit process in Florida actually involves, what it typically costs, and how to keep your project off the slow track.

Step 1: Zoning Verification Before Anything Else

Before drawings, before deposits, someone must confirm that your lot allows the unit you want. That means checking the zoning district's ADU provisions, maximum unit size, setbacks, lot coverage, height limits, parking requirements, and any owner-occupancy or rental conditions. It also means pulling the FEMA flood map for your parcel, because base flood elevation drives the design in much of South Florida. We do this as a formal feasibility step on every ADU construction project — it is far cheaper to learn the constraints in week one than in month four.

Step 2: The Drawing Set

A permit-ready ADU package in South Florida typically includes:

• Site plan on a current survey showing setbacks, coverage, and drainage
• Architectural plans — floor plan, elevations, sections, door/window schedules
• Structural engineering — foundation, wall, and roof design sealed by a Florida engineer
• MEP drawings — mechanical, electrical, and plumbing layouts
• Energy calculations per the Florida Building Code energy provisions
• Product approvals for impact windows, doors, and roofing (Miami-Dade NOAs or Florida Product Approvals in HVHZ jurisdictions)

Incomplete or internally inconsistent sets are the number-one cause of long review cycles. Because our architects and engineers work alongside our builders, our sets go in coordinated — which is a core part of why clients choose us.

Step 3: Plan Review and Comments

The municipality routes your application through zoning, structural, mechanical, electrical, plumbing, and often flood-plain review. Expect at least one round of comments; responding quickly and completely is how projects keep momentum. Typical review timelines in South Florida run from a few weeks in efficient jurisdictions to a few months where volume is high or the application needs multiple revision cycles. A design-build contractor who knows each city's reviewers and preferences shortens this phase more than any other factor.

What ADU Permits Typically Cost

Fees vary by city and project value, but a realistic South Florida budget includes:

Impact fees are the wild card — they differ dramatically by county and utility district, and they are one of the first numbers we pin down in feasibility. All figures are typical ranges; your municipality's fee schedule governs.

Step 4: Inspections Through Certificate of Occupancy

Once the permit is issued, construction proceeds through a fixed sequence of inspections: foundation, slab, framing/tie-beam, roof, rough mechanical/electrical/plumbing, insulation, and final. In HVHZ jurisdictions, inspectors pay particular attention to roof-to-wall connections and impact opening installations. The finish line is the certificate of occupancy (or completion), which is what makes the unit legal to occupy and rent. Keep every approved plan and inspection record — they matter at insurance renewal and resale.

How Long Does the Whole Process Take?

For a detached ADU in South Florida, typical end-to-end timelines look like: feasibility and design, 6–10 weeks; permitting, 1–4 months depending on jurisdiction; construction, 5–9 months. A garage conversion runs shorter on every phase. The single best predictor of a fast project is a complete, coordinated application — the second best is a builder who treats revision comments as same-week work, not someday work. More timeline questions are answered on our FAQ page.

Why Design-Build Changes the Permit Experience

When the architect, engineer, and contractor are separate firms, permit comments turn into rounds of finger-pointing. When they are one firm, comments turn into revisions — usually within days. That is the practical argument for design-build, and it applies to everything we do, from ADUs to home additions and full custom homes.

Work With Xpert Construction Group

Xpert Construction Group handles zoning research, drawings, engineering, permit submission, and every inspection on your behalf. We are a Florida licensed and insured general contractor (CRC 1335930). Contact us for a free consultation and a permit-realistic timeline for your city.