Florida passed a statewide ADU law in 2023 that preempts some of the most common local barriers to accessory dwelling units. But the law is narrower than its headlines suggest — it does not create a uniform statewide right to build an ADU, and municipalities retain control over enough variables to make local research essential for any investor evaluating an ADU project in Florida.

What Florida's 2023 ADU Law Actually Does

HB 1339, signed into law in June 2023, amended Florida Statute 163.31771 to require local governments to adopt an ADU ordinance if they have not already done so, and to prohibit certain specific restrictions. Here is what the law actually prohibits:

  • Local governments may not prohibit ADUs outright in areas zoned for single-family residential use.
  • Local governments may not require owner-occupancy as a condition of ADU approval.
  • Local governments may not impose ADU-specific size limits that are more restrictive than the size limits applicable to the primary dwelling on the same lot.
  • Local governments may not require additional off-street parking for an ADU that is located within a half-mile of a transit stop.

The law also requires that ADU permit applications be processed using the same review procedures as other residential construction — meaning a city cannot create a separate, slower track specifically for ADUs. Applications that meet objective standards must be approved as a ministerial matter.

What the Law Does Not Cover

Florida's 2023 law leaves significant local discretion intact. Municipalities still control:

  • Setbacks and lot coverage: Local setback requirements, lot coverage limits, and impervious surface rules all still apply. A city can set a 10-foot rear setback for ADUs — it just cannot make ADUs impossible through outright prohibition.
  • Design standards: Architectural compatibility requirements, height limits, and exterior material standards are still local prerogatives as long as they apply equally and are not so onerous as to function as a de facto prohibition.
  • Short-term rental rules: Nothing in the 2023 law limits a city's ability to prohibit or restrict short-term rental of ADUs. Several Florida cities and counties have adopted STR restrictions that apply to ADUs regardless of the new state preemption.
  • Parking outside transit areas: For ADUs not within a half-mile of transit, local parking requirements still apply.
  • Impact fees: The 2023 law does not cap or limit impact fees for ADU construction. In some Florida jurisdictions, impact fees for a second dwelling unit can run $10,000–$25,000 or more, which significantly affects project economics.

How Florida's Major Cities Differ

Orlando

Orlando was relatively ADU-friendly before the 2023 state law and has updated its ordinance to align with state requirements. Orlando allows detached ADUs on lots that meet minimum size thresholds (typically 6,000 square feet for most single-family districts). The city's land development code permits ADUs up to 50% of the primary home's square footage or 900 square feet, whichever is greater, for attached units — detached units follow the primary dwelling size comparison rule required by state law. Owner-occupancy is not required.

Tampa

Tampa updated its code following the 2023 law. The city allows ADUs on single-family lots of 5,000 square feet or more. Detached ADUs may be up to 900 square feet or 50% of the primary home's living area. Tampa applies standard setback requirements (5 feet side and rear for most districts), and the city does not require owner-occupancy. Impact fees apply and vary by unit size.

Miami

Miami uses the Miami 21 form-based code rather than a traditional use-based zoning code, which changes how ADU rules are structured. Under Miami 21, accessory units in residential transect zones are governed by the transect zone standards rather than a separate ADU ordinance. Miami's urban core transect zones are generally more permissive about secondary units than its lower-density residential zones. The city's strong short-term rental regulation means that even where an ADU is permitted, STR income projections require separate verification.

Jacksonville

Jacksonville is a consolidated city-county government with a large and varied land base. The city's zoning code was updated post-2023 to comply with state law. ADUs are allowed in residential single-family districts, but Jacksonville's code is detailed about setback requirements (5 feet side and rear is common), maximum height (typically 20–25 feet for detached ADUs), and lot coverage. Because Jacksonville covers such a large geographic area, actual ADU feasibility varies significantly by neighborhood based on lot size distribution and existing lot coverage.

The Practical Research Checklist for Florida ADU Projects

  1. Identify the zoning district on the parcel using the city or county GIS portal.
  2. Pull the local ADU ordinance — look for a dedicated ADU section or search the land development code for "accessory dwelling unit" and "secondary dwelling unit."
  3. Calculate the usable building envelope: lot coverage limit minus existing primary home footprint tells you how much additional coverage is available for a detached unit.
  4. Check setbacks — measure the rear and side yard dimensions on the survey and compare to local setback requirements to determine whether a viable ADU footprint fits.
  5. Research impact fees with the local building department before underwriting. Impact fees in Florida are highly variable and can dramatically affect return on investment.
  6. Check the local short-term rental ordinance if STR income is part of your investment thesis.
  7. Confirm that the property is not in an HOA with CC&Rs that prohibit ADUs or rental use — HOA restrictions are not affected by state law.

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