Adding a unit or an addition to your Florida home
What an accessory dwelling unit is under Florida law, how local rules decide whether you can build one, and who to hire.
Florida homeowners add space for a family member, a rental or a home office. Some of those projects are plain additions to the existing house; others are a second, separate living unit. The rules for each are different, and local rules usually decide.
What counts as an accessory dwelling unit
Florida's statute on accessory dwelling units (section 163.31771) defines an ADU as an ancillary or secondary living unit with a separate kitchen, bathroom and sleeping area, existing either within the primary residence or on the same lot. A garage apartment, a converted garage, a backyard cottage and an in-law suite all fit that description.
Local government decides
The statute says counties and municipalities "may adopt an ordinance to allow accessory dwelling units in any area zoned for single-family residential use." So the first step is local: ask your city or county planning department whether ADUs are allowed at your address, how large they can be, what setbacks apply, whether the unit can be rented, and whether parking is required. Neighbourhoods with deed restrictions or an HOA may have additional limits that no zoning rule overrides.
The affordable-rental provision
The statute also addresses ADUs rented at affordable rates. Where a permit applicant provides an affidavit attesting that the unit will be rented at an affordable rate to households in specified income ranges, the unit may count toward the local government's affordable housing requirements. For this purpose, monthly rent and utilities must not exceed 30 percent of the median adjusted gross annual income threshold for the relevant household category. If you are considering this route, read the full statute and ask your local housing office what applies.
What you will need
- Zoning approval showing the use is allowed.
- Building permits for structure, plumbing, electrical and mechanical work, each with inspections.
- Utility connections, and possibly upgrades: a separate meter, a larger water line, sewer capacity or a septic evaluation.
- Flood and wind compliance for the site. Your local building department can tell you the flood elevation and wind-load rules at your address.
Who to hire
For a house addition or an ADU on a single-family lot, a Certified Residential Contractor (CRC) may take on the whole job, since the statute allows them to build, remodel, repair or improve one-, two- and three-family residences within its height limits. A Certified Building Contractor (CBC) can also build residential buildings up to three stories. A general contractor (CGC) is also an option; this directory does not list them. The licensed contractor then handles or subcontracts the trades. Whatever the class, check the licence on DBPR's Verify a License page and see our licence guide.
An architect or designer
Plans must satisfy the Florida Building Code and local rules. Some contractors offer design-build services; others expect you to bring drawings. Ask who is responsible for the plans, for permit corrections and for engineering such as a structural or foundation design.
Timeline
Expect the process to take longer than the construction itself. Zoning review, plan approval and permitting can take weeks or months depending on the jurisdiction, and utility work is scheduled by the utility. Ask your contractor and your planning office for realistic timelines, and plan for where you will live and park while work is under way.
Budget and paying for it
An ADU costs more than people expect: foundation, utilities, permitting fees and finishes add up. Get itemised quotes, and see our contract checklist for payment and lien protections. Ask your insurer and your lender how a new unit affects your policy and your mortgage, and ask a tax adviser about property taxes and rental income. This guide is general information, not legal or financial advice.
General information only, current as of the date above. The information on Florida Building & Residential Contractor Check is not a recommendation or a guarantee of anyone's work. A license record shows registration status on the date shown, not workmanship, insurance coverage at the time of your job, or suitability for your project. Confirm license, insurance and permits directly before you hire. Rules and programs change; check the official sources linked in this guide.