Can I Build an ADU (Accessory Dwelling Unit) in Florida?
ADU permit requirements. State law, internal vs. detached, basement apartments, and impact fee waivers.
Often yes — many states now require cities to allow at least internal ADUs.
Florida-specific rules
Adopted code: Florida Building Code, 8th Edition (2023); the Florida Building Commission states its effective date is December 31, 2023. ADOPTION IS STATEWIDE AND AUTOMATIC, NOT LOCAL: s. 553.73(6), F.S. provides that "The initial adoption of, and any subsequent update or amendment to, the Florida Building Code by the commission is deemed adopted for use statewide without adoptions by local government." The Code is derived from the International Building Code as a base code with Florida-specific amendments. The Commission must update it on a three-year cycle and 2026 Update materials are already being published, so confirm the edition in force. LOCAL VARIATION RUNS ONE WAY ONLY: s. 553.73, F.S. provides that "Local amendments must be more stringent than the minimum standards described in this section and must be transmitted to the commission within 30 days after enactment" - though DBPR's own guidance states the filing requirement differently, as submitted "at least 30 days prior to being enforced". The two official sources give different deadlines and neither is restated here as the other. A STATEWIDE CARVE-OUT APPLIES TO RESIDENTIAL FIRE SPRINKLERS: IRC section R313 sprinkler mandates may not be incorporated into the Code or adopted as a local amendment, except for a local government whose sprinkler ordinance has been in effect since January 1, 2010. THE OPERATIVE INSTRUMENT HERE HAS NO STATEWIDE EDITION, WHICH IS UNUSUAL IN FLORIDA. Because s. 163.31771(3) is permissive — "A local government MAY adopt an ordinance to allow accessory dwelling units" — the document that decides whether you may build one is a LOCAL ORDINANCE, and a local ordinance has no statewide edition, no three-year cycle and no commission adopting it. It changes when a city council votes. SO THIS TOPIC HAS THE WEAKEST CURRENCY GUARANTEE OF ANY IN THIS GUIDE: the Florida Building Code edition stated above still governs HOW an ADU is built and is stable statewide, but WHETHER you may build one is answered by a document this record cannot cite, cannot date, and which differs between two addresses a mile apart. Chapter 163 is growth-management law rather than building regulation, so it does not appear in code updates at all. Treat the construction requirements in this guide as current and the permission question as unanswered until you have read your own jurisdiction's ordinance.
Sources: Section 553.73, Florida Statutes (2025) - Florida Building Code, Florida Building Commission - official site (current code edition and effective date), Florida DBPR - Building Codes and Standards, Frequently Asked Questions, Florida Building Commission - HB-663 Code Related Requirements (s. 553.73, F.S.)
State Law May Require It
A growing number of states have passed laws requiring cities to allow at least internal ADUs (within the existing footprint of the home — basement apartments, above-garage units, etc.). Many cities also allow detached ADUs, though rules on size and placement vary. Check whether your state has an ADU-enabling law before assuming your city can simply say no.
Types of ADUs
Internal ADUs include basement apartments, converted attic space, and attached additions. Detached ADUs include backyard cottages, converted garages, and purpose-built accessory structures. Each type has different permit requirements and setback rules.
Key Requirements
Most ADUs need: a separate entrance from the primary dwelling, adequate parking (usually one additional off-street space), fire separation (1-hour rating for internal ADUs), and compliance with all building codes for habitable space. Basement ADUs require egress windows in every bedroom.
Reduced Impact Fees
Some states limit impact fees for ADUs, making them cheaper to permit than a full second dwelling. Many cities waive or significantly reduce impact fees for ADUs. Ask your city about current fee schedules — this can save thousands of dollars.
In many states you can build an ADU thanks to state law requiring cities to allow it. Internal ADUs are the easiest path. Start by checking your state's ADU law and your city's specific ADU ordinance.
Permit fees by city in Florida
Verified from each city’s published fee schedule. Where a city has no separate fee listed for this project, open the city page for the current requirements and amount.
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| Permit fee | Source | |
|---|---|---|
| Cape Coral | See city page for the current Residential Building Permit fee | Residential Building Permit → |
| Fort Lauderdale | See city page for the current Residential Building Permit fee | Residential Building Permit → |
| Gainesville | See city page for the current Residential Building Permit fee | Residential Building Permit → |
| Jacksonville | See city page for the current Residential Building Permit fee | Residential Building Permit → |
| Orlando | See city page for the current Residential Building Permit fee | Residential Building Permit → |
| St. Petersburg | See city page for the current Residential Building Permit fee | Residential Building Permit → |
| Tampa | See city page for the current Residential Building Permit fee | Residential Building Permit → |