Florida ADU Rules After HB 1339

Are ADUs Legal in Florida?

Yes. Accessory dwelling units are legal across Florida, and state law expressly favors them. The catch is the verb: under Fla. Stat. 163.31771, a local government may adopt an ordinance allowing ADUs in single-family zones — the statute encourages them but does not yet compel every city to permit one. Whether you can build one comes down to your specific municipality.

An accessory dwelling unit is, in the statute's own words, "an ancillary or secondary living unit, that has a separate kitchen, bathroom, and sleeping area, existing either within the same structure, or on the same lot, as the primary dwelling unit." That definition is the legal line a garage apartment, in-law suite, or backyard cottage has to cross to count as an ADU rather than a shed or a bonus room.

One lot, two distinct homes

The defining feature is independence. A bedroom with an ensuite bath is not an ADU; a unit with its own cooking facilities, its own bathroom, its own sleeping area, and typically its own entrance is. That self-contained quality is what triggers both the zoning question and the building-permit path, because the structure is now a second dwelling, not an extension of the first.

Why Florida wants more of them

The legislative intent behind the statute is affordable housing. Smaller secondary units add supply inside neighborhoods that are already built and already served by roads and utilities, and the law singles out elderly residents and low- to moderate-income renters as intended beneficiaries. That policy goal is exactly why the statewide-mandate bills keep coming back.

What "HB 1339" Actually Does

Here is the part that confuses almost everyone searching this topic. "HB 1339" has become popular shorthand for "the Florida ADU bill," but no enacted statute by that number created an ADU mandate. The real statewide-mandate effort runs through a different lineage of bills — and as of mid-2026 it has not become law.

The bills that carry the mandate

The mandate language has traveled under several bill numbers across sessions. The two most recent vehicles are SB 184 in the 2025 session and SB 48 in the 2026 session. Both aimed to amend Fla. Stat. 163.31771 from "may adopt" to "shall adopt," converting encouragement into obligation.

• SB 184 (2025) — reached the final day of the session before stalling over short-term-rental disagreements; it did not pass.
• SB 48 (2026) — the committee substitute carried the full ADU mandate, but the bill died in Messages on March 13, 2026.
• The "HB 1339" label — circulates in homeowner discussion as a catch-all for this effort; treat it as the topic, not as enacted law.

The practical takeaway is that the mandate is a moving target. Each session the proposal returns with refinements, so the right question is never "what does HB 1339 say" but "what is on the books today versus what is pending."

What the mandate would change if it passed

The proposed bill would do four concrete things. It would require every local government to adopt an ADU ordinance by December 1, 2026; require those units to be approved by ministerial review rather than discretionary hearing; bar cities from demanding the owner live on the property; and bar cities from prohibiting rentals, except rentals shorter than one month.

Ministerial review, defined

Ministerial review means a permit is checked against fixed, objective standards and approved if it conforms — with no judgment call. The bill's language would require ADUs to be approved "without requiring a public hearing; a variance, conditional use permit, special permit, or special exception." That removes the neighborhood-objection process that today can sink an ADU even where zoning technically allows it.

What State Law Allows Today

Until a mandate is enacted, the operative law is the current text of Fla. Stat. 163.31771. It defines ADUs, authorizes cities to allow them, permits them to be used as rentals, and ties certain affordability incentives to an affidavit — but it leaves the decision to permit in each local government's hands.

The affordability affidavit

Where a homeowner uses the statute's affordable-housing incentives, the applicant files an affidavit attesting the unit will be rented at an affordable rate to a qualifying income-eligible person. The statute defines an affordable rental as monthly rent plus utilities not exceeding 30 percent of the income threshold for the applicable income category. This applies only when you take the incentive — not to every ADU.

Homestead protection

A recurring homeowner fear is losing the homestead exemption by adding a rented unit. The mandate bills addressed this directly, providing that a property may not be denied a homestead exemption "solely on the basis of the property containing an accessory dwelling unit." Confirm how your county property appraiser treats the rented portion before you build, because the exemption applies to the owner-occupied home, not the rented unit.

State statute

Defines the ADU, authorizes (does not yet require) local ordinances, and sets affordability and homestead rules.

Local ordinance

The document that actually says yes or no in your city, and sets the dimensional limits.

HOA covenant

A private contract that can restrict your lot more tightly than either of the above.

Reading all three layers together is the only reliable way to know whether your specific lot can host an ADU, because any one of them can be the binding constraint.

What Your City Can Still Require

Even under the strictest version of the mandate, cities keep meaningful control. The bill would strip the power to ban ADUs and the power to demand owner-occupancy, but it preserves a city's authority to regulate how an ADU is built. Those dimensional rules are where most real projects are shaped.

The levers a city keeps

Local governments retain the standard zoning toolkit applied to the ADU envelope. Expect your municipality to set limits across these categories, even where it cannot say no outright.

Because these levers vary city to city, two identical lots in different municipalities can yield very different ADUs. Pulling your specific zoning district's ADU standards before you design is the step that prevents a redraw.

Parking is the quiet veto

On older Florida lots, the parking requirement does more to block ADUs than any size cap. A required extra off-street space can consume the exact corner of the yard where the cottage would sit. The mandate bills limit how aggressive parking demands can be, which is precisely why that provision drew the most local pushback.

Can an HOA Stop Your ADU?

Yes, frequently. This is the hardest fact for homeowners to accept: even if state law and your city both allow an ADU, a private HOA covenant can still prohibit it. State land-use law governs the relationship between you and the government; it does not rewrite the private contract you accepted when you bought into a deed-restricted community.

Why covenants survive the statute

Deed restrictions are contractual. Many Florida subdivisions record covenants limiting each parcel to a single dwelling, banning detached living quarters, or prohibiting rentals — and those run with the land. Neither the current statute nor the pending mandate bills purport to void recorded private covenants, so an HOA's single-dwelling rule can stand even where zoning would permit a second unit.

If any one of those four gates is closed, the project stops there. Read your declaration of covenants and your zoning district before you fall in love with a floor plan, because the HOA gate is the one a permit cannot open.

Does a Garage Conversion Count as an ADU?

It can — if it crosses the dwelling threshold. Converting a garage into a habitable unit becomes an ADU when you add the three things the statute names: a separate kitchen, a bathroom, and a sleeping area. Add those and you have created a second dwelling, which means the full permit path and the ADU rules both apply. The legal line between a finished room and a unit is mapped in our breakdown of a garage conversion versus an ADU.

Where a conversion becomes a dwelling

A garage turned into a home gym or office is not an ADU and not a second dwelling. The moment you install permanent cooking facilities and a bathroom, the use changes, and your building department treats it as habitable space. That reclassification is what pulls in egress, ceiling-height, and life-safety requirements that a garage never had to meet.

• Cooking facilities — a kitchen with, at minimum, a sink, a cooktop, and a refrigerator.
• Full bathroom — adding one triggers a plumbing permit and tie-ins.
• Ceiling height — habitable space generally needs a 7-foot minimum ceiling, which low garages sometimes fail.
• Egress and light — a sleeping area needs compliant egress and natural light per the Florida Building Code.

Each of those line items is a reason a "simple" garage conversion turns into a permitted project. Pricing the conversion as a code-compliant dwelling, not a finished room, is what keeps it from stalling at inspection.

Building an ADU to Code

An approved ADU is a code-built dwelling, and in Florida that means the Florida Building Code (FBC) and your local building department, not just the zoning office. Whether the unit is detached, attached, or a conversion, it needs permits, inspections, and construction that meets structural, wind, and life-safety standards for its location.

The permit stack

A new ADU rarely rides on a single permit. Most projects assemble a building permit plus discipline-specific trade permits, each with its own inspections. Coordinating them in the right sequence is half the job of getting to a certificate of occupancy.

That sequence is identical whether you call us for full ADU construction or hand us a conversion mid-stream — the gates and inspections do not change.