Grand View-on-Hudson · ADU cost
What it costs to build an ADU in Grand View-on-Hudson, NY
An 800 sq ft accessory dwelling unit in Grand View-on-Hudson runs roughly $225k–295k, or about $280–366/sq ft, and that per-square-foot figure sits deliberately above the $229–300/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 Grand View-on-Hudson maps 2 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 Grand View-on-Hudson
Standard finish, slab on grade, on a flat and clear part of the lot, general-contractor margin included. These are structure costs at Rockland County pricing, before the service and septic work a second dwelling can trigger.
| Size | Type | $ / sq ft | Estimated total |
|---|---|---|---|
| 400 sq ft | Studio | $371–$485 | $150k–195k |
| 600 sq ft | One bedroom | $310–$406 | $185k–245k |
| 800 sq ft | One bedroom, larger | $280–$366 | $225k–295k |
| 1,000 sq ft | Two bedroom | $261–$342 | $260k–340k |
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–$12 | $8 | — |
| Foundation | $18–$26 | $18 | — |
| Framing | $29–$36 | $29 | — |
| Envelope - roof, siding, windows | $36–$46 | $36 | — |
| Plumbing | $31–$38 | $18 | 55% |
| Electrical | $21–$26 | $14 | 35% |
| HVAC | $26–$32 | $16 | 45% |
| Insulation | $8–$10 | $8 | — |
| Interior finishes | $36–$48 | $31 | 15% |
| Millwork & cabinetry | $21–$31 | $12 | 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 Grand View-on-Hudson 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 |
|---|---|---|---|---|
| Zone A Residential (the entire area west of River Road. Minimum ADJUSTED lot area 22,000 sf with at least 125 ft of frontage on a public road; a lot qualifies for subdivision only at 54,000 sf of adjusted lot area with 200 ft of frontage, each resulting lot keeping at least 100 ft. Front setback 50 ft from a public road or the Village Park buffer area and 25 ft from any other right-of-way line; principal buildings 25 ft from a property line, other structures 10 ft. Max FAR 20%. No principal building may contain less than 1,500 sf of floor area. No lot coverage percentage is set) | 0.51 ac | 50 / 25 / 25 ft | 35 ft | No |
| Zone B Residential (the strip between River Road and the mean high water mark of the Hudson. Minimum ADJUSTED lot area 10,000 sf with at least 100 ft of frontage on River Road. Setback 25 ft from the right-of-way line; principal buildings 20 ft from a property line, other structures 10 ft. Max FAR 25%. HEIGHT IS A VIEW-CORRIDOR RULE, NOT A FIGURE: to preserve Hudson River views from River Road, no building may rise more than two stories nor more than 4 1/2 ft above the easterly side of River Road, measured every twelve inches in a straight vertical line to the top of the building; where the lot lies substantially at the same level as River Road, nothing may rise more than one story or 15 feet. Lot area is measured to the mean high water mark and no artificial accretion by fill counts. No lot coverage percentage is set) | 0.23 ac | 25 / 20 / 20 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 rentalsShort-term rentals prohibited. Short-term rental is not an available use in Grand View-on-Hudson, on the face of the Zoning Law. Chapter VI-E is a closed list: 'Only those uses listed for each zone as being permitted shall be permitted. Any use not specifically listed as being permitted shall be deemed to be prohibited.' No lodging, transient-accommodation or rental use is listed in either zone; Chapter VI-B states there is no commercial or business district anywhere in the Village; Chapter VI-C bars occupancy by more than one family; and the Home Occupation definition in Chapter IV expressly excludes 'transient accommodations.' Note that this is the closed-list clause doing the work — the Village has no local law that names short-term rentals, so confirm with the Village at (845) 358-2919 before relying on it either way. Separately, since 2025 New York State requires every short-term-rental host to register the unit with the State through the county registry. Separate question from whether you can build the unit.
- Building dept(845) 358-2919
Sizing up a specific parcel in Grand View-on-Hudson?
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 Grand View-on-Hudson runs $229–300/sq ft, about $410k–540k at 1,800 sq ft , plus roughly $86,168 for a conforming lot. See what it costs to build a house in Grand View-on-Hudson.
ADU cost in nearby towns
All Rockland County towns: Clarkstown · Haverstraw · Orangetown · Ramapo · Stony Point · Airmont (Village) · Chestnut Ridge (Village) · Haverstraw (Village) · Hillburn (Village) · Montebello (Village) · New Hempstead (Village) · Nyack (Village) · Piermont (Village) · Pomona (Village) · Sloatsburg (Village) · Spring Valley (Village) · Suffern (Village) · Upper Nyack (Village) · Wesley Hills (Village) · West Haverstraw (Village)
More on Grand View-on-Hudson: Can you build an ADU here? · Zoning for new construction · Rockland County build cost
ADU cost in Grand View-on-Hudson: common questions
How much does it cost to build an ADU in Grand View-on-Hudson, NY?
An 800 sq ft accessory dwelling unit in Village of Grand View-on-Hudson runs roughly $225k–295k at a standard finish, general-contractor margin included. A 400 sq ft studio runs about $150k–195k. 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 Grand View-on-Hudson?
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 $280–366/sq ft against $229–300/sq ft for a full house, even though it is the same trades doing the same work.
Are ADUs allowed in Grand View-on-Hudson?
Village of Grand View-on-Hudson has 2 districts. All districts prohibit ADUs. Check the specific address with the free ADU checker or confirm with the building department at (845) 358-2919 before you spend money on design.
Can I rent an ADU in Grand View-on-Hudson short term?
Short-term rentals prohibited for Village of Grand View-on-Hudson. 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 Rockland 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 Grand View-on-Hudson vary by district and often carry exceptions this page does not show; zoning last reviewed 2026-07-22; verify with the building department at (845) 358-2919 before relying on any answer. Sources: Offsite / Aldo cost engine (costEngine.js + constants.js); zoning dataset (municipalData.js).