ADU in Florida: Zoning, Permits, and Financing Options

An ADU in Florida is legal to build when your county or city has adopted an ordinance allowing it, and the project has to satisfy state statute, local zoning, and the Florida Building Code before anyone moves in. Under Florida Statute 163.31771, an accessory dwelling unit is a secondary living space with its own kitchen, bathroom, and sleeping area, either inside your primary home or in a separate structure on the same lot.¹ Whether you can actually build one, and what you can do with it, depends on layers of rules that vary from one jurisdiction to the next.

What Counts as an ADU

The state definition is broad. A converted garage, a basement apartment, a unit above a detached workshop, or a standalone backyard cottage all qualify, as long as the unit has its own kitchen, bathroom, and sleeping area.¹

An ADU is not a duplex. It cannot be split off from the primary parcel or sold separately. The unit stays tied to the same lot as the main house, and if you sell the home the ADU transfers with it.²

Does Your County or City Actually Allow One

This is the first question to answer, and it is easy to get wrong from a distance. Section 163.31771 says local governments “may” adopt ordinances permitting ADUs in single-family zones. It does not require them to.¹ Some Florida jurisdictions permit ADUs freely, some allow them with heavy restrictions, and some have not adopted an ordinance at all.

Call your local building or planning department, or pull up your zoning code online, and ask two things: whether your zoning district allows an ADU, and whether the authorization comes from a local ordinance or relies on the state statute. That second question determines whether the affordable rent affidavit applies to your permit.

The Legislature has been weighing bills that would make ADU approval mandatory statewide and cut back local restrictions. As of early 2026, the Florida Senate advanced legislation requiring all residential zones to permit ADUs. If that becomes law, several of the local barriers below will loosen. Check the status of current session bills before you plan around today’s rules.

The Affordable Rent Affidavit

When you permit an ADU under the framework of Section 163.31771, the building permit application must include an affidavit stating the unit will be rented at an affordable rate to a person with extremely low, very low, low, or moderate income.¹ “Affordable” means monthly rent plus utilities cannot exceed 30 percent of the median adjusted gross annual income for the applicable income category.

If your city or county has its own, broader ADU ordinance, you may not face this requirement. If your area authorizes ADUs only through the state statute, you likely will. Ask your local building department which framework governs your application.

Local Zoning and Design Limits

Even where the state authorizes ADUs, the physical details are set locally. Pull your property’s zoning designation and read the ADU ordinance before you hire an architect. Most local codes address the same core issues, though the numbers differ across Florida’s 67 counties and hundreds of municipalities.

Maximum size. Codes often cap the ADU at a fixed square footage or as a percentage of the primary home’s living area. Most Florida ADUs land in the 800- to 1,200-square-foot range.
Setbacks. How far the ADU must sit from each property line. Detached ADUs generally face stricter setbacks than attached ones.
Lot coverage. Many jurisdictions cap the total percentage of the lot covered by structures.
Height. Detached ADUs are frequently limited to one story or a set height, though some areas allow two stories.
Parking. Some ordinances require at least one additional off-street space. Proposed state legislation would eliminate this, but current local rules stand.
Design. Some municipalities require the ADU to match the architectural style, exterior materials, or roof pitch of the primary home.

Every ADU also has to meet the Florida Building Code for structural integrity, wind resistance, electrical, plumbing, and energy efficiency, regardless of what the local zoning code says about dimensions.³

The Permit and Inspection Sequence

Once you know what your ordinance allows, the approval process runs in a predictable order. Plan on several months from application to move-in.

Application and Plan Review

Your package goes to the local building and zoning department. Most jurisdictions want detailed architectural plans showing floor layouts, elevations, and structural details, plus a current site survey from a licensed surveyor showing exactly where the ADU will sit relative to property lines, existing structures, and easements. Some cities accept online submissions; others require in-person filing. Fees scale with project scope and construction value.

Staff reviews plans for zoning, land development code, and Florida Building Code compliance. Most delays happen here. A correction notice sends you back to revise and resubmit, so a clean initial submission saves weeks.

Construction and Inspections

After plan approval, construction begins and your contractor (or you, if acting as owner-builder) schedules mandatory inspections at each milestone: foundation, framing, rough electrical, rough plumbing, insulation, and other stages depending on scope. Each inspection must pass before the next phase starts.

A final inspection covers the completed project. Passing it triggers issuance of a Certificate of Occupancy, the document that legally authorizes anyone to live in the unit. Do not let anyone move in before the CO is in hand. Occupying without one can bring fines and complicate insurance claims later.

Renting the Finished ADU

Long-Term Rentals

Leases longer than 30 days are generally allowed where ADUs are allowed. Many local ordinances impose an owner-occupancy rule: the owner has to live in either the main house or the ADU and rent out the other. If the unit was permitted under the state affordable housing framework, the affidavit binds you to affordable rents for qualifying tenants.¹

Short-Term Rentals

Stays under 30 days add a separate layer of state regulation. Under Florida Statute 509.013, a dwelling rented to guests more than three times in a calendar year for periods of less than 30 consecutive days qualifies as a transient public lodging establishment.⁴ That triggers a licensing requirement from the Florida Department of Business and Professional Regulation’s Division of Hotels and Restaurants.⁵

Even with the state license, many local ADU ordinances separately restrict or prohibit short-term rentals. You have to clear both hurdles. Some jurisdictions flatly ban short-term ADU rentals no matter what the state license allows.

HOA Restrictions Can Still Block You

If your property sits inside a homeowners association, the zoning code is not the last word. HOA covenants and deed restrictions are private agreements that run with the land, and they frequently prohibit secondary structures or non-family occupants. Florida has no statewide preemption that overrides those private restrictions. Your county can allow an ADU while your HOA’s declaration of covenants forbids one.

Before you spend money on plans, read your HOA’s governing documents and talk to the association’s architectural review board. Some HOAs grant variances; many do not. Proposed state legislation has addressed whether HOA restrictions can block ADUs, but as of now, private covenants remain enforceable. This is the single most common reason Florida homeowners give up on an ADU project they were otherwise cleared to build.

Paying for Construction

ADU construction in Florida generally runs $150 to $400 per square foot depending on design, location, and finishes, with permitting fees on top. A few common financing paths apply.

Conventional Loans

Fannie Mae treats an ADU the same as any other home feature, so you can finance construction with a standard purchase, refinance, or renovation loan. Borrowers who qualify for a HomeReady loan can count rental income from an existing ADU toward income requirements. Fannie Mae will not finance a property that has multiple ADUs or where the primary residence is a manufactured home.⁶

FHA 203(k) Rehabilitation Loans

If you are converting existing space, the FHA Standard 203(k) rolls purchase or existing mortgage debt and renovation costs into one FHA-insured mortgage, and it covers converting a single-family home into a multi-unit property. A HUD-approved 203(k) consultant evaluates the work and monitors progress, and the total has to stay within FHA loan limits for your county.

Home Equity and Local Programs

Home equity loans and HELOCs work well when you have substantial equity. Cash-out refinancing is another route, though the math is tighter with current interest rates. Some Florida local governments also offer grants or low-interest loans for ADU construction tied to affordable housing commitments.

Insurance and Property Tax

Insurance

A standard homeowners policy may not cover an ADU adequately, especially once you rent it out. Tenant injuries, tenant property damage claims, and liability for conditions in the rental unit fall outside typical homeowner coverage. If you plan to rent, ask your insurer about a landlord endorsement or a separate landlord policy.

Short-term rental use widens the gap further. Many standard policies exclude commercial rental activity outright. An umbrella policy adds a liability layer above your base coverage and becomes more valuable the more often you host.

Property Tax

Adding an ADU raises your property’s assessed value, and property taxes go up accordingly. The county property appraiser reassesses based on the added improvement value. Florida’s homestead exemption applies to your primary residence, but the ADU portion generally does not qualify for a separate homestead exemption.

One narrow exception exists for multigenerational housing. Some counties, including Pinellas, have adopted ordinances providing a property tax reduction for homeowners who build or renovate an ADU to house a parent or grandparent who is at least 62 years old. The reduction covers the increase in assessed value from the ADU or 20 percent of the total assessed value after improvements, whichever is less.⁷ Check whether your county has adopted a similar provision before you assume the full tax increase is locked in.

1
Florida Senate. Florida Statutes 163.31771 – Accessory Dwelling Units
2
Miami-Dade County. Accessory Dwelling Unit (ADU)
3
Pasco County Government. Accessory Dwelling Unit Requirements in Pasco County
4
Florida Senate. Florida Statutes 509.013 – Definitions
5
MyFloridaLicense.com. Hotels and Restaurants Guide to Vacation Rentals and Timeshare Projects
6
Fannie Mae. Accessory Dwelling Units (ADUs)
7
Pinellas County. County Accessory Dwelling Unit Update and Multigenerational Tax Reduction