Beekman · ADU cost
What it costs to build an ADU in Beekman, NY
An 800 sq ft accessory dwelling unit in Beekman 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 Beekman 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 Beekman
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.
| Size | Type | $ / sq ft | Estimated 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 ADU | If it scaled with floor area | Fixed 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 Beekman 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 135,000 Square Feet District | 3.0992 ac | 100 / 40 / 60 ft | 35 ft | Special permit |
| Residential 90,000 Square Feet District | 2.0661 ac | 75 / 30 / 40 ft | 35 ft | Special permit |
| Residential 45,000 Square Feet District | 1.0331 ac | 50 / 20 / 35 ft | 35 ft | Special permit |
| Residential-Mobile Home District | — | 35 / 20 / 20 ft | 35 ft | — |
| Poughquag Hamlet District | 1.0331 ac | 50 / 20 / 35 ft | 35 ft | — |
| Beekmanville Hamlet District | 1.0331 ac | 50 / 20 / 35 ft | 35 ft | — |
| Residential District Condominium Units District | — | 35 / 20 / 35 ft | 35 ft | No |
| Sylvan Cottage District | 0.1148 ac | 10 / 10 / 10 ft | 35 ft | — |
| Town Center District | 1 ac | 0 / 10 / 35 ft | 35 ft | No |
| Neighborhood Shopping District | 0.3444 ac | 60 / 40 / 40 ft | 35 ft | No |
| Highway Commercial District | 0.4591 ac | 60 / 40 / 40 ft | 35 ft | No |
| Mixed Commercial - Light Industrial District | 2.5 ac | 150 / 80 / 80 ft | 45 ft | No |
| Land Conservation District | — | — | — | — |
Residential 135,000 Square Feet District — Schedule B publishes TWO coverage limits and only the building one has a column here: maximum lot coverage by buildings is 6%, and maximum lot coverage by IMPERVIOUS SURFACES INCLUDING THE BUILDING is 10% — the second is the one a driveway and parking count against. Minimum road frontage is 100 ft, a separate column from the lot width. A dwelling unit must have at least 1000 sq ft of interior living space.
Residential 90,000 Square Feet District — Schedule B publishes TWO coverage limits and only the building one has a column here: maximum lot coverage by buildings is 8%, and maximum lot coverage by IMPERVIOUS SURFACES INCLUDING THE BUILDING is 12% — the second is the one a driveway and parking count against. Minimum road frontage is 100 ft, a separate column from the lot width. A dwelling unit must have at least 1000 sq ft of interior living space.
Residential 45,000 Square Feet District — Schedule B publishes TWO coverage limits and only the building one has a column here: maximum lot coverage by buildings is 10%, and maximum lot coverage by IMPERVIOUS SURFACES INCLUDING THE BUILDING is 15% — the second is the one a driveway and parking count against. Minimum road frontage is 100 ft, a separate column from the lot width. A dwelling unit must have at least 1000 sq ft of interior living space.
Residential-Mobile Home District — Schedule B states "NA" for minimum lot area, lot width and road frontage in R-MH — the district is regulated as a mobile home development rather than lot by lot, so those are left empty rather than guessed. It also publishes no impervious-surface limit, only the 25% building coverage. A parking lot must be at least 150 ft from a residential district. A dwelling unit must have at least 475 sq ft of interior living space.
Poughquag Hamlet District, Beekmanville Hamlet District — Schedule B publishes TWO complete rows for this district, and the base row here is the unserviced one. On PUBLIC WATER AND SEWER every figure changes: the lot drops from 45,000 sq ft to 11,250, the interior living space minimum from 1,000 sq ft to 500, the lot width and road frontage from 150 ft and 100 ft to 50 ft each, the front yard from 50 ft to 15, the side from 20 ft to 10 and the rear from 35 ft to 30 — and building coverage rises from 10% to 50%. Schedule B publishes TWO coverage limits and only the building one has a column here: maximum lot coverage by buildings is 10%, and maximum lot coverage by IMPERVIOUS SURFACES INCLUDING THE BUILDING is 15% — the second is the one a driveway and parking count against. On public water and sewer those become 50% and 80%. Minimum road frontage is 100 ft, a separate column from the lot width.
Residential District Condominium Units District — HR is a condominium district, not a hamlet one, and Schedule B gives it no lot-area minimum at all: the area cell publishes a DENSITY instead, a maximum of 8 dwelling units per acre, which is what the land-per-unit figure here carries. Schedule B publishes TWO coverage limits and only the building one has a column here: maximum lot coverage by buildings is 25%, and maximum lot coverage by IMPERVIOUS SURFACES INCLUDING THE BUILDING is 50% — the second is the one a driveway and parking count against. Minimum road frontage is 50 ft, a separate column from the lot width. A dwelling unit must have at least 1000 sq ft of interior living space.
Sylvan Cottage District — Schedule B says the SC lot area "varies" and sends you to § 155-8H, which sets it by BEDROOM COUNT: 5,000 sq ft for a one- or two-bedroom unit, 10,000 for a three-bedroom and 20,000 for a four-bedroom. The base row here is the one- or two-bedroom case, which is the smallest; the rest of the ladder is stated here beside it. The same table caps the floor area of each unit — 1,000, 1,250 and 1,500 sq ft respectively — which is a MAXIMUM, and separate from the 450 sq ft minimum of interior living space Schedule B requires. Yards are "10 feet per story", so the 10 ft recorded here is the single-storey figure and a two-storey building needs 20 ft on every side. No building may stand closer than 15 ft to another building in SC or in an adjoining residential district. Schedule B publishes no building coverage limit for SC, only a 75% impervious-surface limit. Schedule B states no minimum road frontage for this district.
Town Center District — The front yard is a RANGE, "0 to 15 feet", not a minimum — a building may not sit further back than 15 ft. TC publishes a lot minimum of 43,560 sq ft AND a density of 12 residential units per acre; they answer different questions and both are recorded. Commercial on the lower level with residential above is as of right; residential on BOTH levels needs a special use permit. A residential lot may be 6,000 to 10,000 sq ft where it is used for an attached house or a condominium. Every parcel must grant the Town a 35 ft utility easement, located as the Planning Board directs (Note 3). Schedule B publishes TWO coverage limits and only the building one has a column here: maximum lot coverage by buildings is 25%, and maximum lot coverage by IMPERVIOUS SURFACES INCLUDING THE BUILDING is 50% — the second is the one a driveway and parking count against. Minimum road frontage is 100 ft, a separate column from the lot width. A dwelling unit must have at least 800 sq ft of interior living space.
Neighborhood Shopping District, Highway Commercial District — The side and rear yards rise from 40 ft to 60 ft where the lot abuts a residential district (Note 1). A parking lot must be at least 60 ft from a residential district. Schedule B publishes TWO coverage limits and only the building one has a column here: maximum lot coverage by buildings is 25%, and maximum lot coverage by IMPERVIOUS SURFACES INCLUDING THE BUILDING is 50% — the second is the one a driveway and parking count against. Minimum road frontage is 125 ft, a separate column from the lot width. Schedule B publishes no lot width and no interior living space minimum for the commercial districts.
Mixed Commercial - Light Industrial District — The side and rear yards rise from 80 ft to 150 ft where the lot abuts a residential district (Note 2). A parking lot must be at least 60 ft from a residential district. C-3 is the one district allowed 45 ft of height rather than 35. Schedule B publishes TWO coverage limits and only the building one has a column here: maximum lot coverage by buildings is 30%, and maximum lot coverage by IMPERVIOUS SURFACES INCLUDING THE BUILDING is 50% — the second is the one a driveway and parking count against. Minimum road frontage is 125 ft, a separate column from the lot width. Schedule B publishes no lot width and no interior living space minimum for the commercial districts.
Land Conservation District — LC is one of the § 155-5 use districts, but Schedule B publishes no area or bulk column for it — the chapter sets only the uses allowed, in Schedule A. Its purpose is to protect sensitive resource areas, including former public land conveyed into private hands. No dimensional standard is recorded because none is published.
Size limits on record in Beekman
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 Beekman:
- Residential 135,000 Square Feet DistrictFloor area greater than 400 sq ft and less than 800 sq ft; entrance from the side or rear
- Residential 90,000 Square Feet DistrictFloor area greater than 400 sq ft and less than 800 sq ft; entrance from the side or rear
- Residential 45,000 Square Feet DistrictFloor area greater than 400 sq ft and less than 800 sq ft; entrance from the side or rear
- Residential-Mobile Home DistrictFloor area greater than 400 sq ft and less than 800 sq ft; entrance from the side or rear
- Poughquag Hamlet DistrictFloor area greater than 400 sq ft and less than 800 sq ft; entrance from the side or rear
- Beekmanville Hamlet DistrictFloor area greater than 400 sq ft and less than 800 sq ft; entrance from the side or rear
- Residential District Condominium Units DistrictFloor area greater than 400 sq ft and less than 800 sq ft; entrance from the side or rear
- Sylvan Cottage DistrictFloor area greater than 400 sq ft and less than 800 sq ft; entrance from the side or rear
- Town Center DistrictFloor area greater than 400 sq ft and less than 800 sq ft; entrance from the side or rear
- Neighborhood Shopping DistrictFloor area greater than 400 sq ft and less than 800 sq ft; entrance from the side or rear
- Highway Commercial DistrictFloor area greater than 400 sq ft and less than 800 sq ft; entrance from the side or rear
- Mixed Commercial - Light Industrial DistrictFloor area greater than 400 sq ft and less than 800 sq ft; entrance from the side or rear
- Land Conservation DistrictFloor area greater than 400 sq ft and less than 800 sq ft; entrance from the side or rear
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.
- Short-term rentalsShort-term rentals allowed with local rules. STR permit required per Local Law No. 2 of 2022 (Ch. 126.1). Owner may only operate one STR property. Hosted STRs permitted in all residential districts; unhosted STRs subject to zoning review. Contact Town of Beekman Building Dept at (845) 724-5300 for current requirements. Separate question from whether you can build the unit.
- Zoning codeecode360.com/6239722
- Building dept(845) 724-5300
Sizing up a specific parcel in Beekman?
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 Beekman runs $215–282/sq ft, about $390k–510k at 1,800 sq ft , plus roughly $92,203 for a conforming lot. See what it costs to build a house in Beekman.
ADU cost in nearby towns
All Dutchess County towns: Beacon (City) · Poughkeepsie (City) · Amenia · Clinton · Dover · East Fishkill · Fishkill · Hyde Park · La Grange · Milan · North East · Pawling · Pine Plains · Pleasant Valley · Poughkeepsie · Red Hook · Rhinebeck · Stanford · Union Vale · Wappinger · Washington · Fishkill (Village) · Millbrook (Village) · Millerton (Village) · Pawling (Village) · Red Hook (Village) · Rhinebeck (Village) · Tivoli (Village) · Wappingers Falls (Village)
More on Beekman: Can you build an ADU here? · Zoning for new construction · Dutchess County build cost
ADU cost in Beekman: common questions
How much does it cost to build an ADU in Beekman, NY?
An 800 sq ft accessory dwelling unit in Town of Beekman 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 Beekman?
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 Beekman?
Town of Beekman has 13 districts. 5 districts prohibit ADUs, 3 require a special-use permit. 5 districts have incomplete data - verify with the building department at (845) 724-5300. Check the specific address with the free ADU checker before you spend money on design.
Can I rent an ADU in Beekman short term?
Short-term rentals allowed with local rules for Town of Beekman. 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 Beekman 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) 724-5300 before relying on any answer. Sources: Offsite / Aldo cost engine (costEngine.js + constants.js); zoning dataset (municipalData.js).