What Can I Build on a T3-R Lot in Miami?
On a T3-R lot you can build one single-family home, up to 2 stories and 25 feet, on a lot of at least 5,000 SF. The house can cover 50% of the lot on the first floor and 30% on the second. Duplexes, apartments, ADUs and commercial uses are not allowed in T3-R.
T3-R at a glance
| Rule | T3-R |
|---|---|
| Homes allowed | Single-family home only |
| Units per lot | 1 |
| Density | 9 units/acre |
| Max height | 2 stories and 25 ft (to top of slab or eave) |
| Lot coverage | 50% first floor; 30% second floor |
| FLR (floor lot ratio) | None stated (N/A) |
| Minimum lot area | 5,000 SF |
| Minimum lot width | Not covered in this guide |
| Setbacks | Not covered in this guide |
| Parking | 2 spaces per principal home |
| Commercial / office | Not allowed |
The worked example: a 5,000 SF lot
Units by the per-lot rule: 1 (one single-family home)
Ground floor: 5,000 × 50% = 2,500 SF of footprint
Second floor: 5,000 × 30% = 1,500 SF
Upper bound: 2,500 + 1,500 = 4,000 SF of building
Units round down, because density is a maximum. In T3 the per-lot rule binds. The building-area figure is a ceiling from the coverage limits; setbacks will bring it lower.
Height
T3 buildings are limited to 2 stories and 25 feet, measured to the top of the slab or eave. A flat roof gets the same two stories and 25 feet.
Lot coverage and house size
T3 has no floor area ratio. Size is set by lot coverage: 50% of the lot on the first floor and 30% on the second. Coverage counts every building on the lot, including an ancillary building.
What you can build, use by use
For T3-R, Miami 21 allows these homes:
- Single-family home: by right.
- Duplex (two-family): not allowed.
- Apartments (multifamily): not allowed.
- Ancillary dwelling unit (ADU): not allowed. T3-R does allow one ancillary building, limited to one story, for uses like a home office or pool cabana.
Commercial, office, lodging and industrial uses are all prohibited in T3-R.
By right means allowed if the plan meets the code. Warrant means an administrative approval by City staff. Exception means a public hearing. Any use the code doesn't list for the zone is prohibited.
Parking
The code requires a minimum of 2 parking spaces per principal dwelling unit in T3.
Setbacks and lot width
We haven't verified the T3 setbacks and minimum lot width against the current code yet, so we don't state them here rather than give you a number we can't trace.
Bonuses and special programs
The main affordable-housing bonus doesn't apply to T3-zoned land. The ADU rules were amended in 2025.
What can kill a deal on a T3-R lot
- Flood zone. Can set a minimum floor elevation and raise build and insurance costs.
- Easements. A recorded utility or access easement can cross the spot you planned to build on.
- Recorded liens and judgments. Code liens and lawsuits against the property can follow it to the next owner.
- Open or expired permits. A past owner's unfinished permits can block new ones until they're closed out.
- Contamination nearby. A former gas station or dry cleaner next door can trigger environmental review.
- Minimum lot size. A lot under 5,000 SF is below the T3 minimum. Confirm with the City whether a smaller lot is buildable before you price it as one.
Frequently asked questions
Can I build a duplex on a T3-R lot?
No. Miami 21 doesn't allow a two-family residence in T3-R. T3-R allows a single-family home.
Can I add an ADU or granny flat in T3-R?
No ADU. Among the T3 zones, the code allows an ADU only in T3-L and T3-O, on lots with a single-family residence. T3-R does allow one ancillary building, limited to one story, but it can't be a separate dwelling unit.
How tall can a house be in T3-R?
2 stories and 25 feet, measured to the top of the slab or eave.
How big can a T3-R house be on a 5,000 SF lot?
The coverage limits give an upper bound of about 4,000 SF: 2,500 SF on the first floor (50%) and 1,500 SF on the second (30%). Setbacks and design rules usually bring it lower.
What's the minimum lot size in T3-R?
5,000 SF.
Can I open a business in a T3-R home?
Retail, office, restaurant and lodging uses are all prohibited in T3. Home-based work has its own rules, which this guide doesn't cover.
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Other Miami 21 zone guides
New to zone names? Read the plain-English guide to Miami 21.
General information about the Miami 21 code, not legal or zoning advice. Overlays, special plans and prior approvals can change the answer for a lot. Confirm with the City of Miami before you apply for permits.