Accessory Dwelling Units
ADUs in Orlando & Central Florida
An accessory dwelling unit — an ADU, and what most people still call an in-law suite, granny flat, or backyard cottage — is a second, self-contained home on a lot that already has one.
Whether you can build one, how big it can be, and whether you're allowed to rent it out are decided by your jurisdiction, not by your address. In this metro those rules are genuinely opposite, so that is where this page starts.
What counts as an ADU
Florida law defines an accessory dwelling unit as “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” (s. 163.31771, F.S.).
The three words that matter are kitchen, bathroom, sleeping area. A bonus room over the garage with a wet bar is an addition. Add a full kitchen and it becomes a dwelling unit, and a different set of zoning, permitting, and — in unincorporated Orange County — ownership rules attaches to it.
Orange County permits ADUs in three configurations:
- Attached ADU — an “addition to the primary residential unit.”
- Alteration ADU — “alter the use of existing space in the primary residential unit” (the garage-conversion path).
- Detached ADU — “detached from the primary residential unit” (the backyard cottage).
City of Orlando vs. unincorporated Orange County
An “Orlando” mailing address does not tell you which set of rules you are under. Plenty of homes with an Orlando address sit in unincorporated Orange County, and on the question most people actually care about — can I rent it out? — the two jurisdictions land in opposite places.
| City of Orlando | Unincorporated Orange County | |
|---|---|---|
| Owner must live on site? | No. “Either unit may be owner-occupied or rented long-term.” | Yes — “the property owner must occupy either the primary dwelling or the ADU at all times.” |
| Homestead required? | Not stated as a condition. | Yes — ADUs “may only be permitted on properties that qualify as homestead property,” and are “not permitted on non-homestead properties.” |
| Common ownership | “The same person or entity (business, trust, etc.) must own both the main house and the ADU.” | “The primary single-family dwelling and the ADU must remain under the same ownership at all times.” |
| Size cap | 500–1,000 sq ft depending on lot size; 700 sq ft in Historic Districts. Must be “smaller than the main dwelling.” | Not published on the permit page — set by zoning. Confirm with the Zoning Division before you design. |
| Eligible zoning | “If your zoning category starts with R-1, R-2, R-3, MXD, O-1, O-2 or PD, you may be eligible.” | Zoning Division review against Orange County Code Ch. 38 before permitting. |
| Parking | Main house needs one space behind the front-yard setback; an ADU over 500 sq ft needs one more. | Per zoning review. |
Quoted requirements are from the City of Orlando's ADU page and Orange County's Residential ADU permit page. Rules change and other municipalities in our service area (Winter Garden, Ocoee, Apopka, Kissimmee, Clermont, Sanford) set their own — this is general information for the Orlando metro, not legal or zoning advice for your parcel. Verify with your jurisdiction before you commit to a design.
What Florida law actually says
You will read that Florida requires cities and counties to allow ADUs by right. Be careful with that. The operative statute is permissive: “A local government may adopt an ordinance to allow accessory dwelling units in any area zoned for single-family residential use” (s. 163.31771, F.S.).
It sets no deadline, it does not override local zoning, and it does not bar a county from imposing the homestead and owner-occupancy conditions Orange County imposes. Bills to change that have been filed in recent sessions, and a filed bill is not law — we track them, but we will not design your project around one.
The practical consequence: your zoning district decides your project, not a headline about state law. That is the first thing we check.
What an ADU costs in Orlando
A full ADU — kitchen, bath, bedroom, living area — runs $275–$475 per square foot in this market, the same tier as an in-law suite, because that is what it is. It is the most expensive per-foot category we build: an ADU is a complete small house, with its own kitchen rough-in, its own bathroom, and its own HVAC.
The budget path is the alteration ADU — converting existing space such as a garage, which avoids new foundation and roof. Converting rather than building is usually the difference between a project that pencils and one that doesn't.
Plan 16–32 weeks of construction for a detached unit, plus the design-and-permitting runway ahead of it. You can sanity-check a number with our cost calculator, and the Orlando home addition cost guide breaks the tiers down in detail.
ADU Questions, Answered
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