Florida accessory dwelling unit (ADU) law: what the state says, and what your county decides

What is an ADU under Florida law?

An accessory dwelling unit, or ADU, is a second place to live on the same property as a main home. Florida Statutes section 163.31771 describes it as a secondary living unit with its own kitchen, bathroom and sleeping area. It can sit inside the same building as the main home or be a separate building on the same lot.

People call these granny flats, in-law suites or backyard cottages. The legal name in the statute is the accessory dwelling unit. You can read the section on the Florida Senate website: Florida Statutes 163.31771.

If you only want to turn a garage into a bedroom or den with no kitchen, that is a different project. See our guide on the garage conversion permit.

What the state statute actually says

The statute is short. The main points in the 2025 text are these:

• A local government may adopt an ordinance allowing ADUs in any area zoned for single-family residential use. The word is "may," so this is a local choice, not a state order.
• An ADU is a secondary unit with its own kitchen, bathroom and sleeping area, inside the main structure or on the same lot.
• Under subsection (4), a building permit application for an ADU must include an affidavit from the applicant saying the unit will be rented at an affordable rate to people in the income groups the statute lists: extremely low, very low, low or moderate income.
• Under subsection (5), each ADU allowed under such an ordinance counts toward the affordable housing part of the local government's housing plan.

Read that third point twice. The statute ties a permit application to an affordable-rent affidavit. Whether and how your county applies that to your project is a question for the county. We have not confirmed it for Manatee or Hillsborough, so ask before you plan on renting the unit at market rate or using it for family only.

Did the law change in 2026?

We checked a few 2026 bills. CS/HB 313 cites section 163.31771 and died in the House on March 13, 2026. CS/CS/SB 48, a housing bill, died the same day. Its companion, CS/CS/HB 1389, became Chapter 2026-179, and it does not list section 163.31771 among the statutes it cites. SB 962 (Chapter 2026-163) also does not list it.

That means we found no new state rule changing this statute. We did not read every 2026 law, so treat this as a good sign, not a promise. Your county's permit office can tell you what is in force today.

Your county and city write the real rules

Because the state statute is permissive, the details that matter are local: which zoning districts allow an ADU, how big it can be, how far it must sit from the property line, parking, and who can live there. Those rules differ from one county and city to the next, and they change.

We have not confirmed the current ADU details for Manatee County or Hillsborough County, so we will not guess at them here. Go to the source:

• Manatee County: Development Services, 9000 Town Center Parkway, Lakewood Ranch, FL 34202. Phone 941-748-4501 extension 3800, email permitting@mymanatee.org. Permits go through the county's Accela Online Services portal.
• Hillsborough County (unincorporated): permit applications go through the HillsGovHub portal. The county's permit checklist says to send questions about what needs a permit to Permitting@HCFL.gov.
• Inside a city such as Bradenton, Palmetto or Sarasota: ask that city's building and zoning office, because the city may have its own rules.

When you call, ask four things: Is an ADU allowed in my zoning district? Are there size and setback limits for my lot? Is there an occupancy or recording requirement? Does the affordable-rent affidavit apply to my application?

Your HOA may say no even when the county says yes

County approval and HOA approval are separate. A county can allow ADUs while your deed restrictions or HOA documents do not. Read your governing documents before you spend money on drawings. Our guide on HOA approval for remodeling in Florida explains what an HOA can and cannot require.

Where to start before you spend money

Many ADU plans stall on a rule nobody checked. A sensible order keeps you from paying for drawings that cannot be built.

1. Read your HOA or deed documents. They can stop a project the county would allow.
2. Call the county or city. Use the four questions above and write down the name of the person you spoke to and the date.
3. Decide what you actually need. If you want a bedroom and bath for a relative, a room addition or a garage conversion may be simpler than a full second unit. See garage conversion versus room addition.
4. Get a written estimate after a site visit. Lot shape, trees, utilities and flood zone all change the answer, which is why we quote every job after we see the property.

If your lot is in a flood zone, read our guide on remodeling in a flood zone too, since flood rules can apply to any new living space.

How Hildebrand handles ADU projects

Hildebrand Construction & Remodeling builds ADUs and garage conversions in Manatee County, Sarasota County and south Hillsborough. Josh Hildebrand holds Florida Certified Building Contractor license CBC1257253.

We start with a free in-home visit and a written estimate with no trip fee. Every job is quoted after we see the property. We pull every required permit and meet Florida Building Code inspections. Plumbing and electrical are done by licensed trade partners that we manage and coordinate, so one licensed contractor runs the whole job.

If you have an HOA, you file the application and we provide the specs and drawings for it. We do not offer financing, so homeowners use their own bank, HELOC or refinance. See how the job runs on our process page.

Questions homeowners ask