Woodstock · ADU cost
What it costs to build an ADU in Woodstock, NY
An 800 sq ft accessory dwelling unit in Woodstock runs roughly $200k–265k, or about $252–330/sq ft, and that per-square-foot figure sits deliberately above the $206–270/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 town 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 Town of Woodstock maps 9 districts that treat accessory units differently from one another, so read the table below as a starting point rather than a verdict.
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ADU cost by size in Woodstock
Standard finish, slab on grade, on a flat and clear part of the lot, general-contractor margin included. These are structure costs at Ulster County pricing, before the service and septic work a second dwelling can trigger.
| Size | Type | $ / sq ft | Estimated total |
|---|---|---|---|
| 400 sq ft | Studio | $334–$438 | $135k–175k |
| 600 sq ft | One bedroom | $280–$366 | $170k–220k |
| 800 sq ft | One bedroom, larger | $252–$330 | $200k–265k |
| 1,000 sq ft | Two bedroom | $236–$309 | $235k–310k |
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 | $7–$11 | $7 | — |
| Foundation | $17–$23 | $17 | — |
| Framing | $26–$32 | $26 | — |
| Envelope - roof, siding, windows | $32–$41 | $32 | — |
| Plumbing | $28–$34 | $17 | 55% |
| Electrical | $19–$24 | $13 | 35% |
| HVAC | $23–$29 | $15 | 45% |
| Insulation | $7–$9 | $7 | — |
| Interior finishes | $33–$44 | $28 | 15% |
| Millwork & cabinetry | $19–$28 | $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 Woodstock 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 8-Acre (R8) | 8 ac | 25 / 25 / 50 ft | 35 ft | Occupancy restricted |
| Residential 5-Acre (R5) | 5 ac | 25 / 25 / 50 ft | 35 ft | Occupancy restricted |
| Residential 3-Acre (R3) | 3 ac | 25 / 25 / 50 ft | 35 ft | Occupancy restricted |
| Residential 1.5-Acre (R1.5) | 1.5 ac | 25 / 15 / 25 ft | 35 ft | Occupancy restricted |
| Hamlet Residential (HR) | 0.69 ac | 20 / 10 / 25 ft | 35 ft | Occupancy restricted |
| Hamlet Commercial (HC) | 0.23 ac | 15 / 10 / 25 ft | 35 ft | Occupancy restricted |
| Neighborhood Commercial (NC) | 1 ac | 15 / 10 / 25 ft | 35 ft | Occupancy restricted |
| Light Industrial (LI) | 3 ac | 100 / 50 / 100 ft | 35 ft | No |
| Floodway (FW) | — | — | — | No |
Residential 8-Acre (R8) - In a subdivision the Planning Board may approve lots as small as 2 acres, which is not available by right: at most three undersized lots per parcel, no more lots than a fully conforming subdivision would yield, and a deed and plat restriction barring further subdivision.
- At least 85% of the site must be left as open space.
- On a right-of-way under 50 ft wide the front setback is measured from the centre line, with 25 ft added (§ 260-26A).
- The height limit is 2 1/2 stories as well as 35 ft.
- A lot of record predating 2001 that is under the district minimum takes the reduced yards in § 260-26B.
- The floor area ratio governs nonresidential floor area per square foot of site area.
Residential 5-Acre (R5) - In a subdivision the Planning Board may approve lots as small as 2 acres, which is not available by right: at most three undersized lots per parcel, no more lots than a fully conforming subdivision would yield, and a deed and plat restriction barring further subdivision.
- At least 80% of the site must be left as open space.
- On a right-of-way under 50 ft wide the front setback is measured from the centre line, with 25 ft added (§ 260-26A).
- The height limit is 2 1/2 stories as well as 35 ft.
- A lot of record predating 2001 that is under the district minimum takes the reduced yards in § 260-26B.
- The floor area ratio governs nonresidential floor area per square foot of site area.
Residential 3-Acre (R3) - In a subdivision the Planning Board may approve lots as small as 2 acres, which is not available by right: at most three undersized lots per parcel, no more lots than a fully conforming subdivision would yield, and a deed and plat restriction barring further subdivision.
- At least 70% of the site must be left as open space.
- On a right-of-way under 50 ft wide the front setback is measured from the centre line, with 25 ft added (§ 260-26A).
- The height limit is 2 1/2 stories as well as 35 ft.
- A lot of record predating 2001 that is under the district minimum takes the reduced yards in § 260-26B.
- The floor area ratio governs nonresidential floor area per square foot of site area.
Residential 1.5-Acre (R1.5) - The minimum lot drops to 40,000 sq ft with central water or common sewer and 15,000 sq ft with both, and the minimum width to 100 ft in either case; with both, coverage may reach 25% and the floor area ratio 0.63.
- On town-provided central water and common sewer a two-family dwelling needs only the district minimum lot; otherwise § 260-18B(2) applies the per-unit land requirement to each unit.
- At least 70% of the site must be left as open space, 60% with central water or common sewer and 50% with both.
- On a right-of-way under 50 ft wide the front setback is measured from the centre line, with 25 ft added (§ 260-26A).
- The height limit is 2 1/2 stories as well as 35 ft.
- A lot of record predating 2001 that is under the district minimum takes the reduced yards in § 260-26B.
- The floor area ratio governs nonresidential floor area per square foot of site area.
Hamlet Residential (HR) - The minimum lot drops to 25,000 sq ft with central water or common sewer and 10,000 sq ft with both, and the minimum width to 100 ft in either case; coverage may reach 20% and the floor area ratio 0.5 with either, 25% and 0.63 with both.
- On town-provided central water and common sewer a two-family dwelling needs only the district minimum lot; otherwise § 260-18B(2) applies the per-unit land requirement to each unit.
- At least 40% of the site must be left as open space, 30% with central water or common sewer and 25% with both.
- On a right-of-way under 50 ft wide the front setback is measured from the centre line, with 25 ft added (§ 260-26A).
- The height limit is 2 1/2 stories as well as 35 ft.
- The floor area ratio governs nonresidential floor area per square foot of site area.
Hamlet Commercial (HC) - At least 25% of the lot must be kept as open space, and the floor area ratio shown governs nonresidential floor area per square foot of site area.
- On a right-of-way under 50 ft wide, the front setback is measured from the centre line with 25 ft added (§ 260-26A).
- Height is limited to 2 1/2 stories as well as the 35 ft shown.
- One set of dimensional standards applies in HC; the figures do not change with water or sewer service.
Neighborhood Commercial (NC) - The minimum lot drops to 30,000 sq ft with central water or common sewer and 25,000 sq ft with both; coverage may reach 20% and the floor area ratio 0.5 with either, and with both the minimum width is 100 ft, coverage 25% and the ratio 0.63.
- On town-provided central water and common sewer a two-family dwelling needs only the district minimum lot; otherwise § 260-18B(2) applies the per-unit land requirement to each unit.
- At least 40% of the site must be left as open space, 30% with central water or common sewer and 25% with both.
- Adequate space must be left between the front and side lot lines and any structure for sidewalks, curbing, street trees and open space.
- On a right-of-way under 50 ft wide the front setback is measured from the centre line, with 25 ft added (§ 260-26A).
- The height limit is 2 1/2 stories as well as 35 ft.
- The floor area ratio governs nonresidential floor area per square foot of site area.
Light Industrial (LI) - No dwelling is permitted in LI. The figures shown apply where the underlying residential district is R1.5; with R3 underneath the minimum lot is 5 acres, and with R5 it is 8 acres, each with greater width and deeper setbacks.
- In the R3 and R5 cases the floor area ratio is 0.63 and the front, side and rear setbacks are larger than those shown.
- Building coverage is capped at 25% in the R3 and R5 cases.
- At least 60% of the lot must be kept as open space in every case.
- Floor area ratio governs nonresidential floor area per square foot of site area (260 Attachment 2, note 3).
- On a right-of-way under 50 ft, the front setback is measured from the centre line with 25 ft added (§ 260-26A).
- Height is limited to 2 1/2 stories as well as 35 ft.
Floodway (FW) - No development is permitted in the FW district, so the usual dimensional figures do not open up a building envelope here. Every residential and commercial use is prohibited.
- Confirm with the building department before counting on any construction or use on a parcel in this district.
Size limits on record in Woodstock
Where the code states a size cap, it decides which row of the cost table above actually applies to you. These are the caps recorded for Woodstock:
- Residential 8-Acre (R8)At least 250 sq ft for a studio or 320 for a one-bedroom, and no more than 800 sq ft
- Residential 5-Acre (R5)At least 250 sq ft for a studio or 320 for a one-bedroom, and no more than 800 sq ft
- Residential 3-Acre (R3)At least 250 sq ft for a studio or 320 for a one-bedroom, and no more than 800 sq ft
- Residential 1.5-Acre (R1.5)At least 250 sq ft for a studio or 320 for a one-bedroom, and no more than 800 sq ft
- Hamlet Residential (HR)At least 250 sq ft for a studio or 320 for a one-bedroom, and no more than 800 sq ft
- Hamlet Commercial (HC)At least 250 sq ft for a studio or 320 for a one-bedroom, and no more than 800 sq ft
- Neighborhood Commercial (NC)At least 250 sq ft for a studio or 320 for a one-bedroom, and no more than 800 sq ft
- Light Industrial (LI)At least 250 sq ft for a studio or 320 for a one-bedroom, and no more than 800 sq ft
- Floodway (FW)At least 250 sq ft for a studio or 320 for a one-bedroom, and no more than 800 sq ft
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 Central Hudson 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.
- Stretch energy code Adopted (January 2023). New accessory construction has to meet the higher NYStretch standard on envelope, air sealing and equipment.
- Short-term rentalsShort-term rentals allowed with registration. Short term rental is allowed with an annual registration, and use is limited to 120 nights per calendar year. There is no requirement that the owner live on the property. Separate question from whether you can build the unit.
- Zoning codeecode360.com/8008828
- Building dept(845) 679-2113
Sizing up a specific parcel in Woodstock?
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Building a full house instead?
A standard-finish house in Woodstock runs $206–270/sq ft, about $370k–485k at 1,800 sq ft , plus roughly $13,409 for a conforming lot. See what it costs to build a house in Woodstock.
ADU cost in nearby towns
All Ulster County towns: Kingston (City) · Denning · Esopus · Gardiner · Hardenburgh · Hurley · Lloyd · Marbletown · Marlborough · New Paltz · Olive · Plattekill · Rochester · Rosendale · Saugerties · Shandaken · Shawangunk · Ulster · Wawarsing
More on Woodstock: Can you build an ADU here? · Zoning for new construction · Ulster County build cost
ADU cost in Woodstock: common questions
How much does it cost to build an ADU in Woodstock, NY?
An 800 sq ft accessory dwelling unit in Town of Woodstock runs roughly $200k–265k at a standard finish, general-contractor margin included. A 400 sq ft studio runs about $135k–175k. 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 Woodstock?
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 $252–330/sq ft against $206–270/sq ft for a full house, even though it is the same trades doing the same work.
Are ADUs allowed in Woodstock?
Town of Woodstock has 9 districts. 7 districts allow ADUs with occupancy restrictions, 2 do not. Check the specific address with the free ADU checker or confirm with the building department at (845) 679-2113 before you spend money on design.
Can I rent an ADU in Woodstock short term?
Short-term rentals allowed with registration for Town of Woodstock. 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 Ulster 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 Town of Woodstock vary by district and often carry exceptions this page does not show; zoning last reviewed Feb 2026; verify with the building department at (845) 679-2113 before relying on any answer. Sources: the Offsite / Aldo cost engine and zoning dataset.