Otisville · ADU cost
What it costs to build an ADU in Otisville, NY
An 800 sq ft accessory dwelling unit in Otisville 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 Otisville maps 6 districts that treat accessory units differently from one another, so read the table below as a starting point rather than a verdict.
ADU cost by size in Otisville
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 Otisville 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 |
|---|---|---|---|---|
| Single-Family Residence | 0.344 ac | 30 / 20 / 30 ft | 35 ft | No |
| Multiple-Family Residence | 0.344 ac | 30 / 20 / 30 ft | 35 ft | No |
| Single-Family Residence (large lot) | 0.918 ac | 100 / 25 / 30 ft | 35 ft | No |
| Commercial | 0.115 ac | 0 / 5 / 15 ft | 35 ft | No |
| Commercial | 0.23 ac | 30 / 20 / 25 ft | 45 ft | No |
| Heavy Commercial / Light Industrial | 0.23 ac | 30 / 50 / 30 ft | 45 ft | No |
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. Read in full 2026-08-27 against the Comprehensive Zoning Law of 2011 with Amendments (111 pp., amended through September 2015), its Appendix A Comprehensive Zoning and Planning Definitions, and the Village's complete published Local Laws index (92 entries). Nothing regulates short-term rental, transient occupancy, rental registration or rental licensing. THE DECISIVE PROVISION IS § 2.4.5: 'Any use not permitted by this Law shall be deemed to be prohibited. Any list of prohibited uses contained in any section of this Law shall not be deemed to be an exhaustive list.' Every district section repeats the closure in its own words — § 3.1.1 R-1: 'no building or premises shall be used ... for any use except the following.' APPENDIX A DEFINES THREE LODGING USES AND THE DISTRICT REGULATIONS LIST NONE OF THEM. 'Bed and Breakfast — A residence where overnight guests are lodged for compensation. The residence shall be occupied by the owner'; 'Boarding, Lodging, or Rooming House'; and 'Lodging Facility: Any hotel, motel, inn, or other establishment providing sleeping accommodations for transient guests ... excluding bed-and-breakfast establishments'. All three are defined and none is a permitted, conditional or accessory use in any district. Appendix A also defines 'Transient Occupancy — the occupancy of a room for sleeping purposes by the same person or persons for a period of 30 days or less', a defined term the zoning text never once uses. R-1 permits a one-family dwelling and municipal parks; its conditional uses are places of worship, schools and residential group homes; its accessory uses are home occupations, garden and tool houses and private garages. THE ONLY TRANSIENT LODGING ANYWHERE IN THE VILLAGE is § 3.7.1.1(i) — 'Motels/hotels provided that minimum lot size is increased 1,500 square feet for each unit over four' — in the C-2 General Commercial District. On the face of the code a short-term rental of a house in R-1 is an unlisted use and therefore prohibited, but that reading has not been confirmed with the Village, which is why this is recorded as no local law found rather than as a ban. ONE LIMIT ON COMPLETENESS: the Village's own Laws page carries the banner 'THIS SECTION IS UNDER CONSTRUCTION. NOT ALL LOCAL LAWS ARE LISTED HERE.' Since 2025 New York State requires every short-term-rental host to register the unit with the State through the county registry regardless of what the municipality allows. Call the Village Clerk at (845) 386-5172 before relying on this absence. Separate question from whether you can build the unit.
- Building dept(845) 386-5172
Sizing up a specific parcel in Otisville?
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 Otisville runs $211–276/sq ft, about $380k–495k at 1,800 sq ft . See what it costs to build a house in Otisville.
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) · Florida (Village) · Goshen (Village) · Greenwood Lake (Village) · Harriman (Village) · Highland Falls (Village) · Kiryas Joel (Village) · Maybrook (Village) · Monroe (Village) · Montgomery (Village) · South Blooming Grove (Village) · Tuxedo Park (Village) · Walden (Village) · Warwick (Village) · Washingtonville (Village) · Woodbury (Village)
More on Otisville: Can you build an ADU here? · Zoning for new construction · Orange County build cost
ADU cost in Otisville: common questions
How much does it cost to build an ADU in Otisville, NY?
An 800 sq ft accessory dwelling unit in Village of Otisville 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 Otisville?
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 Otisville?
Village of Otisville has 6 districts. All districts prohibit ADUs. Check the specific address with the free ADU checker or confirm with the building department at (845) 386-5172 before you spend money on design.
Can I rent an ADU in Otisville short term?
No local short-term-rental law on record - which is not the same as permission for Village of Otisville. 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 Otisville vary by district and often carry exceptions this page does not show; zoning last reviewed 2026-07-12; verify with the building department at (845) 386-5172 before relying on any answer. Sources: Offsite / Aldo cost engine (costEngine.js + constants.js); zoning dataset (municipalData.js).