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Red Hook · ADU cost

What it costs to build an ADU in Red Hook, NY

800 sq ft ≈ $210k–275k $263–345/sq ft 13 districts Central Hudson

An 800 sq ft accessory dwelling unit in Red Hook runs roughly $210k–275k, or about $263–345/sq ft, and that per-square-foot figure sits deliberately above the $215–282/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 Red Hook maps 13 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 Red Hook

Standard finish, slab on grade, on a flat and clear part of the lot, general-contractor margin included. These are structure costs at Dutchess County pricing, before the service and septic work a second dwelling can trigger.

SizeType$ / sq ftEstimated total
400 sq ft Studio $349–$457 $140k–185k
600 sq ft One bedroom $292–$382 $175k–230k
800 sq ft One bedroom, larger $263–$345 $210k–275k
1,000 sq ft Two bedroom $246–$322 $245k–320k

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 ADUIf it scaled with floor areaFixed per unit
Site work $8–$12 $8
Foundation $17–$24 $17
Framing $27–$34 $27
Envelope - roof, siding, windows $34–$43 $34
Plumbing $29–$36 $17 55%
Electrical $19–$25 $13 35%
HVAC $24–$30 $15 45%
Insulation $8–$10 $8
Interior finishes $34–$46 $29 15%
Millwork & cabinetry $19–$29 $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 Red Hook 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
Waterfront Conservation 10 ac 100 / 75 / 75 ft 35 ft No
Limited Development 10 ac 100 / 75 / 75 ft 35 ft Special permit
Rural Development 5-Acre 5 ac 75 / 50 / 50 ft 35 ft Special permit
Rural Development 3-Acre 3 ac 60 / 35 / 35 ft 35 ft Special permit
Residential 1.5-Acre 1.5 ac 50 / 20 / 25 ft 35 ft Special permit
Residential 1-Acre 1 ac 35 / 15 / 25 ft 35 ft Special permit
Hamlet 1.5 ac 50 / 20 / 25 ft 35 ft Special permit
Institutional 10 ac 100 / 50 / 50 ft 35 ft Special permit
Business 1 1 ac 80 / 20 / 50 ft 35 ft Special permit
Business 2 1.5 ac 80 / 20 / 50 ft 35 ft Special permit
Hamlet Business 1 ac 40 / 20 / 50 ft 35 ft Special permit
Agricultural Business District 25 / 100 / 100 ft 35 ft
Traditional Neighborhood Development District

Waterfront Conservation — Residential uses in the WC District carry additional special permit criteria under § 143-53. Minimum lot width is 500 ft and minimum frontage 300 ft — separate columns, and the frontage is always the smaller. Every yard column prints two figures. The first is the principal structure and is the one recorded here; the second is the minimum setback for OFF-STREET PARKING and its accessways — 60 ft front, 50 ft side, 50 ft rear — which binds separately, and does not apply to a driveway serving a one- or two-family dwelling (Note 1). A minimum of 90% of the lot must be open space. For a nonresidential use at least 40% of that open space must sit between the front building line and the right-of-way, or 50% on a corner lot (Note 4). Where a side or rear yard abuts land in a MORE restricted district, that district's requirement applies instead (Note 3, § 143-22). Front setbacks increase on parcels fronting a user highway or inside a designated scenic area (Note 2, Article V). The lot minimum is the figure for a permitted one- or two-family dwelling and its accessory structures; other residential types and nonresidential uses take the standards in Article V or the special-permit standards at § 143-52 et seq.

Limited Development — Minimum lot width is 400 ft and minimum frontage 240 ft — separate columns, and the frontage is always the smaller. Every yard column prints two figures. The first is the principal structure and is the one recorded here; the second is the minimum setback for OFF-STREET PARKING and its accessways — 60 ft front, 50 ft side, 50 ft rear — which binds separately, and does not apply to a driveway serving a one- or two-family dwelling (Note 1). A minimum of 85% of the lot must be open space. For a nonresidential use at least 40% of that open space must sit between the front building line and the right-of-way, or 50% on a corner lot (Note 4). Where a side or rear yard abuts land in a MORE restricted district, that district's requirement applies instead (Note 3, § 143-22). Front setbacks increase on parcels fronting a user highway or inside a designated scenic area (Note 2, Article V). The lot minimum is the figure for a permitted one- or two-family dwelling and its accessory structures; other residential types and nonresidential uses take the standards in Article V or the special-permit standards at § 143-52 et seq.

Rural Development 5-Acre — Minimum lot width is 300 ft and minimum frontage 200 ft — separate columns, and the frontage is always the smaller. Every yard column prints two figures. The first is the principal structure and is the one recorded here; the second is the minimum setback for OFF-STREET PARKING and its accessways — 50 ft front, 25 ft side, 25 ft rear — which binds separately, and does not apply to a driveway serving a one- or two-family dwelling (Note 1). A minimum of 80% of the lot must be open space. For a nonresidential use at least 40% of that open space must sit between the front building line and the right-of-way, or 50% on a corner lot (Note 4). Where a side or rear yard abuts land in a MORE restricted district, that district's requirement applies instead (Note 3, § 143-22). Front setbacks increase on parcels fronting a user highway or inside a designated scenic area (Note 2, Article V). The lot minimum is the figure for a permitted one- or two-family dwelling and its accessory structures; other residential types and nonresidential uses take the standards in Article V or the special-permit standards at § 143-52 et seq.

Rural Development 3-Acre — Minimum lot width is 240 ft and minimum frontage 160 ft — separate columns, and the frontage is always the smaller. Every yard column prints two figures. The first is the principal structure and is the one recorded here; the second is the minimum setback for OFF-STREET PARKING and its accessways — 35 ft front, 20 ft side, 20 ft rear — which binds separately, and does not apply to a driveway serving a one- or two-family dwelling (Note 1). A minimum of 80% of the lot must be open space. For a nonresidential use at least 40% of that open space must sit between the front building line and the right-of-way, or 50% on a corner lot (Note 4). Where a side or rear yard abuts land in a MORE restricted district, that district's requirement applies instead (Note 3, § 143-22). Front setbacks increase on parcels fronting a user highway or inside a designated scenic area (Note 2, Article V). The lot minimum is the figure for a permitted one- or two-family dwelling and its accessory structures; other residential types and nonresidential uses take the standards in Article V or the special-permit standards at § 143-52 et seq.

Residential 1.5-Acre — Minimum lot width is 180 ft and minimum frontage 135 ft — separate columns, and the frontage is always the smaller. Every yard column prints two figures. The first is the principal structure and is the one recorded here; the second is the minimum setback for OFF-STREET PARKING and its accessways — 25 ft front, 10 ft side, 15 ft rear — which binds separately, and does not apply to a driveway serving a one- or two-family dwelling (Note 1). A minimum of 70% of the lot must be open space. For a nonresidential use at least 40% of that open space must sit between the front building line and the right-of-way, or 50% on a corner lot (Note 4). Where a side or rear yard abuts land in a MORE restricted district, that district's requirement applies instead (Note 3, § 143-22). Front setbacks increase on parcels fronting a user highway or inside a designated scenic area (Note 2, Article V). The lot minimum is the figure for a permitted one- or two-family dwelling and its accessory structures; other residential types and nonresidential uses take the standards in Article V or the special-permit standards at § 143-52 et seq.

Residential 1-Acre — The side yard may be cut to ZERO for zero-lot-line residential development (Note 5). Minimum lot width is 160 ft and minimum frontage 120 ft — separate columns, and the frontage is always the smaller. Every yard column prints two figures. The first is the principal structure and is the one recorded here; the second is the minimum setback for OFF-STREET PARKING and its accessways — 15 ft front, 5 ft side, 15 ft rear — which binds separately, and does not apply to a driveway serving a one- or two-family dwelling (Note 1). A minimum of 65% of the lot must be open space. For a nonresidential use at least 40% of that open space must sit between the front building line and the right-of-way, or 50% on a corner lot (Note 4). Where a side or rear yard abuts land in a MORE restricted district, that district's requirement applies instead (Note 3, § 143-22). Front setbacks increase on parcels fronting a user highway or inside a designated scenic area (Note 2, Article V). The lot minimum is the figure for a permitted one- or two-family dwelling and its accessory structures; other residential types and nonresidential uses take the standards in Article V or the special-permit standards at § 143-52 et seq.

Hamlet — The Hamlet District publishes TWO complete rows, one for Upper Red Hook and one for Annandale and Barrytown, and the base row here is Upper Red Hook. In ANNANDALE AND BARRYTOWN every figure is larger: 5 acres rather than 1.5, 300 ft of lot width and 200 ft of frontage rather than 180 and 135, a 75 ft front yard, 50 ft side and 50 ft rear, 5% coverage and 80% open space, with parking set back 50/25/25 ft. Which hamlet the parcel is in is a matter of location, so both rows are stated here rather than one being applied town-wide. In Annandale and Barrytown the front yard may be reduced to 25 ft where that matches the established setback on contiguous parcels on the same street (Note 6). In Upper Red Hook the front yard is instead 100 ft for parcels with frontage on the WEST side of Route 9 (Note 8). The side yard may be cut to zero for zero-lot-line residential development (Note 5). Minimum lot width is 180 ft and minimum frontage 135 ft — separate columns, and the frontage is always the smaller. Every yard column prints two figures. The first is the principal structure and is the one recorded here; the second is the minimum setback for OFF-STREET PARKING and its accessways — 25 ft front, 10 ft side, 15 ft rear — which binds separately, and does not apply to a driveway serving a one- or two-family dwelling (Note 1). A minimum of 70% of the lot must be open space. For a nonresidential use at least 40% of that open space must sit between the front building line and the right-of-way, or 50% on a corner lot (Note 4). Where a side or rear yard abuts land in a MORE restricted district, that district's requirement applies instead (Note 3, § 143-22). Front setbacks increase on parcels fronting a user highway or inside a designated scenic area (Note 2, Article V). The lot minimum is the figure for a permitted one- or two-family dwelling and its accessory structures; other residential types and nonresidential uses take the standards in Article V or the special-permit standards at § 143-52 et seq.

Institutional — A permitted residential dwelling in the I District does not take these standards: it follows the LD District if it sits west of NYS Route 9G and the RD3 District if it sits anywhere else in the town (the schedule's Institutional footnote). That split is geographic, so it is stated here rather than recorded as a condition. Residential uses in WC and I also carry the additional special permit criteria at § 143-53. Minimum lot width is 400 ft and minimum frontage 320 ft — separate columns, and the frontage is always the smaller. Every yard column prints two figures. The first is the principal structure and is the one recorded here; the second is the minimum setback for OFF-STREET PARKING and its accessways — 60 ft front, 25 ft side, 25 ft rear — which binds separately, and does not apply to a driveway serving a one- or two-family dwelling (Note 1). A minimum of 75% of the lot must be open space. For a nonresidential use at least 40% of that open space must sit between the front building line and the right-of-way, or 50% on a corner lot (Note 4). Where a side or rear yard abuts land in a MORE restricted district, that district's requirement applies instead (Note 3, § 143-22). Front setbacks increase on parcels fronting a user highway or inside a designated scenic area (Note 2, Article V). The lot minimum is the figure for a permitted one- or two-family dwelling and its accessory structures; other residential types and nonresidential uses take the standards in Article V or the special-permit standards at § 143-52 et seq.

Business 1 — A permitted residential dwelling here is governed by the R1 District standards instead of the district's own (the schedule's residential cross-reference footnote), and that cross-reference is recorded as a condition below. Minimum lot width is 150 ft and minimum frontage 120 ft — separate columns, and the frontage is always the smaller. Every yard column prints two figures. The first is the principal structure and is the one recorded here; the second is the minimum setback for OFF-STREET PARKING and its accessways — 40 ft front, 10 ft side, 25 ft rear — which binds separately, and does not apply to a driveway serving a one- or two-family dwelling (Note 1). A minimum of 40% of the lot must be open space. For a nonresidential use at least 40% of that open space must sit between the front building line and the right-of-way, or 50% on a corner lot (Note 4). Where a side or rear yard abuts land in a MORE restricted district, that district's requirement applies instead (Note 3, § 143-22). Front setbacks increase on parcels fronting a user highway or inside a designated scenic area (Note 2, Article V). The lot minimum is the figure for a permitted one- or two-family dwelling and its accessory structures; other residential types and nonresidential uses take the standards in Article V or the special-permit standards at § 143-52 et seq.

Business 2 — A permitted residential dwelling here is governed by the R1 District standards instead of the district's own (the schedule's residential cross-reference footnote), and that cross-reference is recorded as a condition below. Minimum lot width is 200 ft and minimum frontage 160 ft — separate columns, and the frontage is always the smaller. Every yard column prints two figures. The first is the principal structure and is the one recorded here; the second is the minimum setback for OFF-STREET PARKING and its accessways — 40 ft front, 10 ft side, 25 ft rear — which binds separately, and does not apply to a driveway serving a one- or two-family dwelling (Note 1). A minimum of 35% of the lot must be open space. For a nonresidential use at least 40% of that open space must sit between the front building line and the right-of-way, or 50% on a corner lot (Note 4). Where a side or rear yard abuts land in a MORE restricted district, that district's requirement applies instead (Note 3, § 143-22). Front setbacks increase on parcels fronting a user highway or inside a designated scenic area (Note 2, Article V). The lot minimum is the figure for a permitted one- or two-family dwelling and its accessory structures; other residential types and nonresidential uses take the standards in Article V or the special-permit standards at § 143-52 et seq.

Hamlet Business — Parking setbacks in HB are not on this schedule; they are set by § 143-49.3, which also carries the rest of the HB standards. The side yard is DOUBLED where the lot is adjacent to a residential district (Note 3). The front yard is 100 ft rather than 40 for parcels with frontage on the WEST side of Route 9 (Note 8). A permitted residential dwelling here is governed by the R1 District standards instead of the district's own (the schedule's residential cross-reference footnote), and that cross-reference is recorded as a condition below. Minimum lot width is 150 ft and minimum frontage 120 ft — separate columns, and the frontage is always the smaller. A minimum of 50% of the lot must be open space. For a nonresidential use at least 40% of that open space must sit between the front building line and the right-of-way, or 50% on a corner lot (Note 4). Where a side or rear yard abuts land in a MORE restricted district, that district's requirement applies instead (Note 3, § 143-22). Front setbacks increase on parcels fronting a user highway or inside a designated scenic area (Note 2, Article V). The lot minimum is the figure for a permitted one- or two-family dwelling and its accessory structures; other residential types and nonresidential uses take the standards in Article V or the special-permit standards at § 143-52 et seq.

Agricultural Business District — The schedule gives AB no lot area, lot width or frontage, and § 143-39.1 adds none — it sets yards and coverage only. The setbacks recorded here are the NONRESIDENTIAL ones. A new principal RESIDENTIAL building needs only 10 ft from any property boundary, and an accessory structure 3 ft, which is recorded as a condition. Off-street parking and accessways are set back 25 ft at the front and 60 ft at the side and rear. The 7% coverage applies to uses not in a farmstead complex or building envelope. Unenclosed manure storage must be 100 ft from any lot line, wetland, stream, water body or potable well. A minimum of 80% of the lot must be open space. For a nonresidential use at least 40% of that open space must sit between the front building line and the right-of-way, or 50% on a corner lot (Note 4).

Traditional Neighborhood Development District — The schedule publishes no figure of any kind for TND — every column sends you to § 143-49.1. The district is form-based and is divided into three mapped subdistricts, Commercial Center, Residential Neighborhood and Office-Industrial, each with its own standards, so there is no single row to record and none is guessed here. Two features of those standards have no column of their own and are worth stating: the front setback is a build-to RANGE with a maximum of 18 ft in both the Residential Neighborhood and the Commercial Center subdistricts, so a building may not be set further back; and the Commercial Center caps lot frontage at a maximum as well as a minimum. Read § 143-49.1 subsections I through Q for the subdistrict this parcel is in.

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Size limits on record in Red Hook

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 Red Hook:

Costs an ADU adds that a house does not

Sizing up a specific parcel in Red Hook?

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 Red Hook runs $215–282/sq ft, about $390k–510k at 1,800 sq ft , plus roughly $38,658 for a conforming lot. See what it costs to build a house in Red Hook.

ADU cost in nearby towns

ADU cost in Red Hook: common questions

How much does it cost to build an ADU in Red Hook, NY?

An 800 sq ft accessory dwelling unit in Town of Red Hook runs roughly $210k–275k at a standard finish, general-contractor margin included. A 400 sq ft studio runs about $140k–185k. 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 Red Hook?

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 $263–345/sq ft against $215–282/sq ft for a full house, even though it is the same trades doing the same work.

Are ADUs allowed in Red Hook?

Town of Red Hook has 13 districts. 10 districts allow ADUs with a special-use permit, 1 does not. 2 districts have incomplete data - verify with the building department at (845) 758-4600. Check the specific address with the free ADU checker before you spend money on design.

Can I rent an ADU in Red Hook short term?

Short-term rentals allowed with local rules for Town of Red Hook. 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 Dutchess 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 Red Hook vary by district and often carry exceptions this page does not show; zoning last reviewed 2026-08-16; verify with the building department at (845) 758-4600 before relying on any answer. Sources: Offsite / Aldo cost engine (costEngine.js + constants.js); zoning dataset (municipalData.js).

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