Florida · ADU cost
What it costs to build an ADU in Florida, NY
An 800 sq ft accessory dwelling unit in Florida runs roughly $205k–270k, or about $258–337/sq ft, and that per-square-foot figure sits deliberately above the $211–276/sq ft a full house costs here. An ADU still needs one whole kitchen, one whole bath, its own service panel and its own heating plant no matter how small you draw it, and those costs do not shrink with the floor plan, so they land on half the square footage and push the rate up. Whether the village will let you build one is a separate question from what it costs, and it gets answered parcel by parcel rather than townwide, since the Village of Florida maps 9 districts that treat accessory units differently from one another, so read the table below as a starting point rather than a verdict.
Check a specific parcel for an ADU in Aldo, free →
ADU cost by size in Florida
Standard finish, slab on grade, on a flat and clear part of the lot, general-contractor margin included. These are structure costs at Orange County pricing, before the service and septic work a second dwelling can trigger.
| Size | Type | $ / sq ft | Estimated total |
|---|---|---|---|
| 400 sq ft | Studio | $342–$447 | $135k–180k |
| 600 sq ft | One bedroom | $286–$374 | $170k–225k |
| 800 sq ft | One bedroom, larger | $258–$337 | $205k–270k |
| 1,000 sq ft | Two bedroom | $241–$315 | $240k–315k |
400 sq ft — One room plus a bath. Garage conversions and small backyard cottages land here.
600 sq ft — The most common detached build - a real bedroom, full kitchen, one bath.
800 sq ft — Room for a proper living area. Still a single bath and one kitchen.
1,000 sq ft — About as large as most codes allow an accessory unit to go.
Why the rate is higher than a house
The systems below are priced for an 800 sq ft unit. The middle column is what each system would cost if it simply shrank with the floor plan; the left column is what it actually costs once you account for the equipment a dwelling needs one of regardless of size. The gap between the two columns is the whole reason small builds price the way they do.
| System | $ / sq ft in an ADU | If it scaled with floor area | Fixed per unit |
|---|---|---|---|
| Site work | $8–$11 | $8 | — |
| Foundation | $17–$24 | $17 | — |
| Framing | $26–$33 | $26 | — |
| Envelope - roof, siding, windows | $33–$42 | $33 | — |
| Plumbing | $29–$35 | $17 | 55% |
| Electrical | $19–$24 | $13 | 35% |
| HVAC | $24–$29 | $15 | 45% |
| Insulation | $8–$9 | $8 | — |
| Interior finishes | $33–$45 | $28 | 15% |
| Millwork & cabinetry | $19–$29 | $11 | 55% |
The fixed-per-unit share is a modeling assumption, not a figure from the code: it is our estimate of how much of each system's budget buys equipment a dwelling needs exactly one of - a kitchen rough-in, a bath group, a service panel, a heating plant - and therefore does not shrink when the unit does. Site work, foundation, framing, envelope and insulation are treated as scaling straight with floor area, which understates the premium slightly, because a small building carries more envelope per square foot of floor than a large one.
What the Florida code says about accessory units
Whether you can build one, and how large, is decided by the district your parcel sits in rather than by the town as a whole. The table shows how each mapped district treats ADUs alongside the lot and setback standards a second unit still has to fit inside. District boundaries and conditions vary, so treat it as a starting point and confirm the district that applies to your parcel.
| District | Min lot | Setbacks F / S / R | Max height | ADU |
|---|---|---|---|---|
| Residential One-Family | 0.46 ac | 30 / 18 / 30 ft | 35 ft | No |
| Residential One- and Two-Family | 0.23 ac | 25 / 12 / 30 ft | 35 ft | No |
| Rural Residential | 0.92 ac | 40 / 20 / 50 ft | 35 ft | No |
| Residential Annexation | 1.84 ac | 65 / 40 / 65 ft | 35 ft | No |
| Residence/Office | 0.23 ac | 25 / 12 / 30 ft | 35 ft | No |
| Central Shopping | 0.23 ac | 0 / 0 / 0 ft | 35 ft | No |
| General Commercial | 1 ac | 25 / 15 / 25 ft | 35 ft | No |
| Industrial Park | 1 ac | 50 / 20 / 30 ft | 40 ft | No |
| Multifamily Residential | 5 ac | 40 / 30 / 30 ft | 35 ft | No |
Residential One-Family - The two side yards must add up to 45 ft, so meeting the 18 ft minimum on one side is not enough; the other side has to be wider than the minimum. Older undersized lots follow a separate standard.
- Existing small lots in any residence district are governed by § 119-8H.
- Each dwelling unit requires 20,000 square feet of land, the same as the minimum lot area.
- A dwelling must have at least 1,000 square feet of livable floor area.
Residential One- and Two-Family - Because only 5,000 square feet of land is required per dwelling unit, a two-family house can sit on the minimum 10,000 square foot lot here, which is not possible in the one-family district.
- Existing small lots in any residence district are governed by § 119-8H.
- Each dwelling must have at least 750 square feet of livable floor area, the smallest the Village asks.
Rural Residential - Existing small lots in any residence district are governed separately, under § 119-8H, rather than by the dimensions shown here, so an older undersized parcel may be buildable on different terms. Check with the building department before assuming a lot must meet the full figures.
Residential Annexation - Beyond the figures shown, a separate rule, § 119-8H, governs existing small lots in any residence district, so an older undersized parcel here may be treated differently.
- The 80,000 square feet of lot area is also the land required for each dwelling unit, so added units need added land.
- Check with the building department on how § 119-8H applies before relying on it for a specific parcel.
Residence/Office - The figures shown apply to residential use. A commercial use in RO takes 80 ft of lot width rather than 50, with a 12 ft side yard and a rear yard of only 10 ft instead of 30 ft.
- A commercial use keeps the same 100 ft lot depth and 25 ft front setback, and building coverage remains capped at 50%.
- No combined side yard figure is published for a commercial use, and the land per dwelling unit and minimum livable floor area standards do not apply to it.
- For a commercial use on a lot within 25 ft of a residence district boundary, the yards are set instead at 12 ft to the side and 5 ft to the rear.
- Existing small lots in a residence district are governed by § 119-8H.
Central Shopping - Buildings may come to the street and to neighbouring lots, but where a lot sits within 25 ft of a residence district boundary, 10 ft is required to the side and 5 ft to the rear.
- A multifamily conversion in this district falls outside the village's multifamily standards and is governed by § 119-43B(17) instead.
Multifamily Residential - The land required per dwelling unit climbs with bedroom count, from 3,500 square feet for an efficiency of one habitable room to 6,000 square feet for a three-bedroom or larger, so the unit mix, not the five-acre minimum, sizes the building.
- Attached single-family dwellings take more land per unit, not less: 4,800 square feet for a one-bedroom, rising to 6,800 for a two-bedroom and 10,500 for a three-bedroom.
- Attached single-family dwellings are held to different lot figures: 224 ft of width, 100 ft of depth, a 30 ft front yard and a 35 ft rear yard.
- For attached single-family dwellings the side yard is 0 ft, except that an end-row attached or townhouse dwelling needs at least 15 ft.
- Every attached dwelling must be at least 20 ft wide.
- A one-bedroom flat takes 4,000 square feet of land per unit.
- Multifamily conversions in the CS district are excluded from these standards.
Costs an ADU adds that a house does not
- Septic and water A second dwelling adds bedrooms to the design flow, which on an unsewered parcel often means expanding or replacing the existing system rather than tapping it. This is the single most common reason an ADU budget moves after design, and it is site-specific enough that no model should quote it - get it evaluated early.
- Utility service Orange & Rockland territory. A detached unit needs power run to it, and whether it goes on its own meter or subfeeds the main house changes both the cost and the permit path.
- Access and parking Many codes require an added parking space for the accessory unit, and a detached unit usually needs a driveway extension or a path, both of which count against a lot-coverage or impervious-surface cap.
- Short-term rentalsNo local short-term-rental law on record - which is not the same as permission. The Village of Florida has no local short-term rental law, and that is not the same as permission. Confirm with the Village building department before counting on short-term rental income. Separate question from whether you can build the unit.
- Zoning codeecode360.com/9271698
- Building dept(845) 651-7626
Sizing up a specific parcel in Florida?
Aldo pulls the exact zoning district, setbacks, and build feasibility for any parcel — before you buy. Enter your email to open Aldo and run your free report.
Building a full house instead?
A standard-finish house in Florida runs $211–276/sq ft, about $380k–495k at 1,800 sq ft , plus roughly $5,430 for a conforming lot. See what it costs to build a house in Florida.
ADU cost in nearby towns
All Orange County towns: Middletown (City) · Newburgh (City) · Port Jervis (City) · Blooming Grove · Chester · Cornwall · Crawford · Deerpark · Goshen · Greenville · Hamptonburgh · Highlands · Minisink · Monroe · Montgomery · Mount Hope · New Windsor · Newburgh · Palm Tree · Tuxedo · Wallkill · Warwick · Wawayanda · Chester (Village) · Cornwall-on-Hudson (Village) · Goshen (Village) · Greenwood Lake (Village) · Harriman (Village) · Highland Falls (Village) · Kiryas Joel (Village) · Maybrook (Village) · Monroe (Village) · Montgomery (Village) · Otisville (Village) · South Blooming Grove (Village) · Tuxedo Park (Village) · Walden (Village) · Warwick (Village) · Washingtonville (Village) · Woodbury (Village)
More on Florida: Can you build an ADU here? · Zoning for new construction · Orange County build cost
ADU cost in Florida: common questions
How much does it cost to build an ADU in Florida, NY?
An 800 sq ft accessory dwelling unit in Village of Florida runs roughly $205k–270k at a standard finish, general-contractor margin included. A 400 sq ft studio runs about $135k–180k. Those are structure costs on an easy site and do not include the septic, water or electrical service work a second unit often triggers.
Why does an ADU cost more per square foot than a house in Florida?
Because a lot of a dwelling's cost is per dwelling, not per square foot. One kitchen, one bath group, one service panel and one heating plant cost about the same in an 800 sq ft cottage as in a 1,800 sq ft house, so on the smaller unit they get spread over less than half the floor area. That is why an ADU here prices at $258–337/sq ft against $211–276/sq ft for a full house, even though it is the same trades doing the same work.
Are ADUs allowed in Florida?
Village of Florida has 9 districts. All districts prohibit ADUs. Check the specific address with the free ADU checker or confirm with the building department at (845) 651-7626 before you spend money on design.
Can I rent an ADU in Florida short term?
No local short-term-rental law on record - which is not the same as permission for Village of Florida. ADU rules and short-term-rental rules are set separately, so a unit you are allowed to build is not automatically one you are allowed to rent nightly. Confirm both before you underwrite the build on short-term-rental income.
ADU costs are modeled estimates in current 2026 dollars at the Orange County regional index, general-contractor margin included, derived from Offsite's cost engine with a stated adjustment for the equipment a dwelling needs one of regardless of size. They are planning numbers for decision-support only - not a bid, quote, or guarantee, and not legal, architectural or engineering advice. They cover the structure and exclude septic expansion, utility service runs, site work beyond a flat and clear pad, and permit fees. ADU eligibility, size, owner-occupancy and permit conditions in the Village of Florida vary by district and often carry exceptions this page does not show; zoning last reviewed 2026-09-30; verify with the building department at (845) 651-7626 before relying on any answer. Sources: the Offsite / Aldo cost engine and zoning dataset.