ADU Permitting in Florida: What Homeowners Need to Know

The Two-Phase Reality of ADU Permitting

Most Florida homeowners are surprised to learn that buying or selecting an ADU unit is only the beginning of the permitting process. Even if you purchase a Florida state pre-approved modular ADU unit, you still need a complete site-specific construction document package before the local building department will issue a building permit.

This creates what we call the permitting gap — the space between having an ADU and being able to legally install it. Understanding this gap is the first step to navigating it efficiently.

What Documents Are Required for an ADU Permit?

A complete ADU permit package submitted to the local Authority Having Jurisdiction (AHJ) must include:

• Topographic survey — prepared by a licensed Florida surveyor. Shows property boundaries, elevation contours, existing structures, trees, and utilities. This is the foundation everything else is built on.
• Site plan — coordinates the survey with the ADU footprint, existing structures, proposed additions (porches, stairs, carports), drainage, zoning setbacks, and utility connections. Must demonstrate compliance with local zoning ordinances.
• Elevations — architectural drawings showing the ADU and existing structures from all sides. Must show compliance with flood elevation requirements and zoning height limits.
• Foundation plan — engineered plans and structural calculations specific to your site. Includes wind load analysis, soil bearing assumptions, and the complete anchoring system (holddowns, concrete anchors, hardware). Required to be signed and sealed by a Florida PE.
• Energy performance calculations — an R405 energy model showing the unit meets Florida Energy Code requirements for your specific location, orientation, and climate zone.
• MEP documents — electrical and plumbing drawings showing how the ADU connects to site utilities. HVAC integration documents if applicable.
• Florida state pre-approval package — if your ADU is a factory-built modular unit, the manufacturer's DBPR approval is included in the submission.

ADU Permitting Works for All Construction Systems

The permitting process described above applies regardless of how the ADU is built. Whether your ADU is:

• Site-built — traditionally constructed on your property
• Modular — factory-built sections assembled on a permanent foundation
• Panelized — pre-fabricated wall panels assembled on site
• Kit homes — pre-cut components delivered and assembled

...the local jurisdiction requires the same site-specific package. The construction system affects the foundation design and some structural details, but not the overall permitting process.

How Long Does ADU Permitting Take?

The timeline has two components you control and one you do not:

• Survey (by others): 1–3 weeks to commission and receive a completed topographic survey.
• Construction documents (Design Build Florida): 2 weeks from Notice to Proceed once all input documents are received.
• AHJ review (building department): Varies significantly by county. Smaller counties with lighter workloads may review in 2–4 weeks. Miami-Dade and Broward can take 6–10 weeks or longer. Using a private provider for plan review — permitted under the Florida Building Code — can compress this to as little as 5 business days.

A realistic total from project start to permit in hand: 6 to 16 weeks, depending on county and whether you use private plan review.

How Design Build Florida Helps

Design Build Florida exists specifically to fill the permitting gap. We prepare the complete site-specific construction document package — site plan, foundation plan, elevations, energy calculations, and MEP documents — signed and sealed by a Florida licensed Professional Engineer, formatted for electronic submission to your local AHJ.

Standard turnaround is 2 weeks from Notice to Proceed. Up to two AHJ review cycles are included. Expedited production is available.

Frequently Asked Questions

How long does ADU permitting take in Florida?

Document production takes 2 weeks. AHJ review adds 2–10 weeks depending on county. Total realistic timeline: 6–16 weeks from project start to permit in hand.

Do I need a separate permit if my ADU is Florida state pre-approved?

Yes. The state pre-approval covers the unit itself, not the site-specific installation. A local building permit is always required, and it requires a complete site-specific construction document package.

How much does ADU permitting cost in Florida?

Professional construction document preparation typically ranges from $4,500 to $8,500 depending on scope. Topographic survey (by others) adds $800–$2,000. Local filing fees vary by county and project valuation.

Can I hire my own surveyor?

Yes, and you should. The topographic survey must be prepared by a licensed Florida surveyor — it is not part of the engineering scope. We coordinate directly with your surveyor once you have engaged them.