A detached ADU is a separate small house on the same lot as your home, with its own kitchen, bathroom and entry. It offers the most privacy of any ADU type and the most freedom in layout. It is also usually the most expensive, since the foundation, structure and roof are all new.
How large can a detached ADU be in Orlando?
It depends on your zoning district and lot size. As of October 2026, the City of Orlando's ADU page gives lot-size thresholds by district. In R-1, for example, a lot needs 6,000 sq ft for an ADU up to 500 sq ft and 9,000 sq ft for one up to 1,000 sq ft. In R-1AA the thresholds are 10,000 and 15,000 sq ft. Many districts cap the unit at 500 sq ft.
Two more limits apply on every lot: the ADU must be smaller than the main house, and the house and ADU together cannot exceed a floor area ratio of 0.50. In the city's own example, a 5,500 sq ft lot in R-2A allows 2,750 sq ft of combined floor area.
Where on the lot can it go?
- Not in front of the main house.
- Within the setbacks the code sets for accessory structures.
- On waterfront lots, at least 15 feet from the normal high-water line or wetland boundary, with a 12-foot height limit within 15 feet of the water.
- Off any dedicated utility, stormwater or sewer easement.
Detached ADUs over 500 sq ft in R-2, R-3, MXD and office districts must also meet the city's tandem development standards.
Does a detached ADU need parking?
As of October 2026, the city requires the main house to keep one parking space behind the front yard setback, and an ADU over 500 sq ft needs one more space. Staying at 500 sq ft or less avoids the extra space.
What does Orlando require it to look like?
The ADU must match the main house's exterior finish and repeat similar architectural details. Alternative designs and corner lots may need an Appearance Review Determination before the building permit. In historic districts the ADU is capped at 700 sq ft and needs a Major Review Certificate of Appropriateness.
What Florida building rules shape the design?
Every new ADU is built to the Florida Building Code, which sets the wind loads a structure must resist for its location. The current edition is the 8th; the 9th edition (2026) takes effect on December 31, 2026, so the filing date can decide which edition your plans follow. A detached ADU also needs its own electric and water meters in Orlando, which affects where the unit sits relative to the street.
What does a detached ADU depend on?
- Lot size and district. These set the maximum size.
- Flood status. A lot in a FEMA flood zone changes the foundation and floor height.
- Utilities. Separate meters, the sewer route and the electrical service.
- Trees and drainage. Where water flows today, and what has to stay.
Costs are covered in the Orlando ADU cost guide.