ADU Cost and Financing in Florida (2026)
What it actually costs to build an ADU in Miami, Tampa, Orlando, and Jacksonville, plus the financing options Florida homeowners use to pay for one.
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How Much Does an ADU Cost in Florida?
Florida ADU rules are set city by city, and so are build costs — hurricane-resistant construction requirements push South Florida above the rest of the state.
| Project Type | Miami | Tampa | Orlando |
|---|---|---|---|
| Garage conversion | $55,000–$90,000 | $40,000–$75,000 | $40,000–$80,000 |
| New detached ADU | $140,000–$230,000 | $110,000–$180,000 | $100,000–$180,000 |
| Junior ADU (interior conversion) | $30,000–$55,000 | $25,000–$45,000 | $25,000–$45,000 |
Statewide, Florida ADUs run $90,000–$230,000 for a typical detached build — see the full breakdown, including Jacksonville, in our Florida ADU laws guide. Run your own numbers, including finish level and size, with the ADU cost calculator.
What Drives Your Budget
- Hurricane compliance: Miami-Dade and Broward County require wind-mitigation features — impact windows, reinforced roof tie-downs, engineered foundations — that add $15,000–$40,000 to a build. This is the single biggest reason South Florida costs run above Central Florida.
- Project type: a garage conversion reuses an existing foundation and roof, so it's consistently the cheapest route to a finished unit. New detached construction costs more but gives you a purpose-built layout.
- Size: maximum size varies by city — Miami allows up to 900 sq ft in some zones, Orlando caps at 850 sq ft or 50% of the primary dwelling.
- Finish level: builder-grade finishes stay near the low end of these ranges; custom cabinetry, higher-end appliances, and upgraded flooring push toward the top.
Financing a Florida ADU
Most Florida homeowners pay for an ADU with one of these:
- HELOC — draw against your home equity as construction proceeds; interest-only during the draw period, variable rate.
- Cash-out refinance — roll ADU costs into a new first mortgage at a fixed rate; makes the most sense if you're also refinancing a higher-rate existing loan.
- Construction loan — underwritten against the property's value after the ADU is built, useful if you don't have enough current equity for a HELOC.
- Personal loan — unsecured and faster to close, typically used for smaller garage-conversion or JADU budgets under $90,000.
Lenders generally cap total borrowing at 80–85% of your home's value, so the equity you have today sets the ceiling on what you can finance without a construction-loan product. For a full side-by-side comparison of rates and terms, see our ADU financing options guide.
ADU-Friendly Lenders to Compare
Start by getting quotes from a few lenders that work with ADU borrowers so you can compare rates and draw schedules before you commit:
- LendingTree — compare HELOC and cash-out refinance offers from multiple lenders at once.
- Better.com — fully online cash-out refinance with no lender fees.
- RenoFi — construction loans underwritten against your ADU's after-build value, useful if you don't have 20%+ equity today.
ROI Example: Tampa Garage Conversion
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Here's what a real payback timeline looks like for a mid-range Florida project:
- Conversion cost: $60,000
- Permits and soft costs: $8,000
- Total investment: $68,000
- Market rent (Tampa, 1BR): $1,450/month → $17,400/year gross
- Net income after 10% expenses: $15,660/year
- Cap rate: 23%
- Break-even: about 4.3 years
A detached unit in Miami runs the numbers differently: a $200,000 build renting for $2,000/month ($24,000/year gross, $21,600 net) pencils out to a 10.8% cap rate and roughly a 9.3-year break-even — lower than the garage-conversion example because hurricane-compliant construction costs more upfront, but still well inside the "strong investment" range. Model your own property with the ADU ROI calculator.
Permitting Notes for Florida
Florida has no statewide ADU preemption — the Live Local Act (HB 1339, 2023, amended by HB 1239, 2024) incentivizes affordable housing near commercial corridors but doesn't override single-family zoning. Each city sets its own rules: Miami requires owner-occupancy in some zones, Orlando doesn't, and permit timelines range from 60–120 days in Tampa and Orlando to 120–180 days in Miami-Dade, Broward, and Palm Beach due to mandatory hurricane compliance review. Full detail on every city's specifics is in our Florida ADU laws guide.
Frequently Asked Questions
How much does it cost to build an ADU in Florida?
Florida ADU costs typically range from $90,000 to $230,000 for a new detached unit. Garage conversions run $40,000–$90,000 depending on city, and hurricane-compliant construction in Miami-Dade and Broward County adds $15,000–$40,000 versus Central Florida.
What's the best way to finance an ADU in Florida?
It depends on your equity position. A HELOC offers flexibility for staged construction draws, a cash-out refinance locks in a fixed rate, and a construction loan works if you don't yet have enough equity for a HELOC. See our ADU financing options guide for a full comparison.
Does Florida require a permit for an ADU?
Yes. Permits are issued city by city since Florida has no statewide ADU law. Tampa and Orlando typically process permits in 60–120 days; Miami-Dade, Broward, and Palm Beach counties often take 120–180 days because of hurricane-compliance review.
Find an ADU Builder in Florida
The fastest way to turn these ranges into a real number is to get quotes from builders working in your city. Our Florida ADU contractor directory lists vetted builders serving Miami, Tampa, Orlando, and Jacksonville — filter by service type to find garage-conversion specialists versus new-construction builders.
Are you an ADU builder serving Florida homeowners? List your business to get in front of homeowners searching for a contractor in your area.