ADU · Sullivan County

Can you build an ADU in Delaware, NY?

Town of Delaware has 7 districts. All districts prohibit ADUs. Check your address to confirm the district that applies to your parcel:

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What the Delaware code says

The town has no accessory dwelling unit. The practical way to add one is converting a house, which § 220-41 allows wherever a two-family is permitted: by right in DR, CAL-B-1, CAL-R-1, R-1, RU and B-1, and by special use in PUD. That makes two full dwellings.

Conditions the code attaches:

Only a dwelling that existed when § 220-41 was adopted can be converted, so confirm with the building department that the house qualifies.
The lot needs only the district's single-family minimum, but the converted house must meet new construction standards for lot coverage and off-street parking.
Structural alterations need an architect's or engineer's certification, and sewage disposal must be certified for the number of units (§ 220-41C, D).
In DR, net density is capped at one dwelling unit per two acres (§ 220-30A).
A new two-family needs twice the single-family minimum lot in RU and 1.5 times it elsewhere (§ 220-40B).
In R-1 and RU the single-family minimum may be halved with central water and sewage. Building department: (845) 887-5250.

What the Delaware code indicates by district

The table below shows how each district treats ADUs, alongside the lot and setback standards that govern a second unit. District boundaries and conditions vary, so treat this as a starting point and confirm the district that applies to your parcel.

District	Min lot	Setbacks F / S / R	Max height	ADU
Delaware River District	2 ac	50 / 50 / 50 ft	35 ft	No
Residential District	0.92 ac	50 / 30 / 50 ft	35 ft	No
Rural District	1.84 ac	50 / 30 / 50 ft	45 ft	No
Business District	0.17 ac	20 / 10 / 30 ft	60 ft	No
Callicoon Business District	2 ac	50 / 25 / 25 ft	40 ft	No
Callicoon Residential District	0.92 ac	50 / 30 / 50 ft	35 ft	No
Planned Unit Development District	0.92 ac	50 / 30 / 50 ft	45 ft	No

Delaware River District - The Delaware River District asks 2 acres, a 200 foot lot width and depth, 50 feet front, 50 feet to one side with 100 feet for both sides, and 50 feet rear. Building height stops at 35 feet and lot coverage at 10,000 square feet or 15%, whichever is less.

Residential density may not exceed one dwelling unit per two acres.
No building, structure or part of a septic system may stand within 100 feet of the normal high water mark of the Delaware River, and a new lot bordering the river needs 200 feet of frontage along it.
On a street whose right of way is under 50 feet, the front yard is measured from the center line of the roadway and 25 feet is added.
Cluster development is a special use on a contiguous parcel of at least 5 acres.
A cluster lot on on-site water or sewage may fall to 0.9183 acre, with 150 feet of width and depth, 25% coverage and yards of 50 feet front, 30 feet side and 50 feet rear.
A cluster lot on central water and sewage may fall to 0.2296 acre, with 70 feet of width, 100 feet of depth, 35% coverage and yards of 25 feet front, 10 feet side and 15 feet rear.

Residential District - The Residential District asks 40,000 square feet, a 150 foot lot width and depth, 50 feet front, 30 feet to one side with 70 feet for both sides, and 50 feet rear. Building height stops at 35 feet and lot coverage at 25%.

On central water and central sewage the minimums drop by 50%: 0.4591 acre, 75 feet of width and depth, and yards of 25 feet front, 15 feet one side, 35 feet both sides and 25 feet rear.
A two family dwelling needs 1.5 times the single family lot minimum, which is 1.3774 acres.
Converting an existing building to a two family dwelling keeps the single family minimum of 0.9183 acre.
A multiple dwelling project is a special use, must be served by central water and central sewage, and counts 20,000 square feet of land for each dwelling unit.
Cluster development is a special use on a contiguous parcel of at least 5 acres served by central water and central sewage.
A cluster lot may fall to 0.2296 acre, with 70 feet of width, 100 feet of depth, 35% coverage and yards of 25 feet front, 10 feet side and 15 feet rear.

Rural District - The Rural District asks 80,000 square feet, a 200 foot lot width and depth, 50 feet front, 30 feet to one side with 70 feet for both sides, and 50 feet rear. Building height stops at 45 feet and lot coverage at 15%.

On central water and central sewage the minimums drop by 50%: 0.9183 acre, 100 feet of width and depth, and yards of 25 feet front, 15 feet one side, 35 feet both sides and 25 feet rear.
The special uses the schedule marks with an asterisk need at least 4 acres.
A two family dwelling needs twice the single family lot minimum, which is 3.6731 acres, while converting an existing building to one keeps 1.8365 acres.
Cluster development is a special use on a contiguous parcel of at least 5 acres.
A cluster lot on on-site water or sewage may fall to 0.9183 acre, with 150 feet of width and depth, 25% coverage and yards of 50 feet front, 30 feet side and 50 feet rear.
A cluster lot on central water and sewage may fall to 0.2296 acre, with 70 feet of width, 100 feet of depth, 35% coverage and yards of 25 feet front, 10 feet side and 15 feet rear.

Business District - The Business District asks 7,500 square feet, a 50 foot lot width, a 100 foot lot depth, 20 feet front, 10 feet to one side with 20 feet for both sides, and 30 feet rear. Building height stops at 60 feet and lot coverage at 65%.

The front yard may be reduced to line up with adjacent buildings.
Residential development follows the Residential District standards: 0.9183 acre, 150 feet of width and depth, and yards of 50 feet front, 30 feet one side, 70 feet both sides and 50 feet rear.
Residential building height there stops at 35 feet and residential lot coverage at 25%.
A two family dwelling needs 1.5 times that single family minimum, which is 1.3774 acres.
A multiple dwelling project is a special use, must be served by central water and central sewage, and counts 5,000 square feet of land for each dwelling unit.
Cluster development is not available in this district.

Callicoon Business District - The Callicoon Business District asks 2 acres without central water and sewage, a 200 foot lot width and depth, 50 feet front, 25 feet side and 25 feet rear. Building height stops at 40 feet and lot coverage at 65%.

On central water and central sewage the lot minimum is 0.2296 acre, with 50 feet of width, 100 feet of depth, and yards of 20 feet front, 10 feet one side, 20 feet both sides and 30 feet rear.
The front yard may be reduced to line up with adjacent buildings.
On the downtown Callicoon parcels the front yard is zero feet, side yards are 5 feet each and the rear yard is 10 feet, with building coverage at 85% and lot coverage at 100%.
A two family dwelling needs 1.5 times the single family lot minimum, which is 3 acres without central water and sewage and 0.3444 acre with them.
A multiple dwelling project is a special use, must be served by central water and central sewage, and counts 7,500 square feet of land for each dwelling unit.
No building, structure or part of a septic system may stand within 100 feet of the normal high water mark of the Delaware River, and a new lot bordering the river needs 200 feet of frontage along it.

Callicoon Residential District - The Callicoon Residential District takes the Residential District figures: 40,000 square feet, a 150 foot lot width and depth, 50 feet front, 30 feet to one side with 70 feet for both sides, and 50 feet rear. Building height stops at 35 feet and lot coverage at 25%.

On central water and central sewage the minimums drop by 50%: 0.4591 acre, 75 feet of width and depth, and yards of 25 feet front, 15 feet one side, 35 feet both sides and 25 feet rear.
A two family dwelling needs 1.5 times the single family lot minimum, which is 1.3774 acres, while converting an existing building to one keeps 0.9183 acre.
A multiple dwelling project is a special use, must be served by central water and central sewage, and counts 20,000 square feet of land for each dwelling unit.
Cluster development is a special use on a contiguous parcel of at least 5 acres served by central water and central sewage, and its lots may fall to 0.2296 acre.
A cluster lot takes 70 feet of width, 100 feet of depth, 35% coverage and yards of 25 feet front, 10 feet side and 15 feet rear.
No building, structure or part of a septic system may stand within 100 feet of the normal high water mark of the Delaware River, and a new lot bordering the river needs 200 feet of frontage along it.

Planned Unit Development District - The Planned Unit Development District allows 2 dwelling units or equivalent dwelling units per acre. Building height stops at 45 feet and lot coverage at 15%. Every use must be served by central water and central sewage, and every use is a special use.

The schedule publishes no lot area, width, depth or yard minimum for this district.
The district tract must cover at least 50 contiguous acres, though a smaller tract may be approved.
A building site no closer than 300 feet to the property borders may reach 60 feet in height.
A single family dwelling on on-site water or sewage follows the Residential District standards: 0.9183 acre, 150 feet of width and depth, 35 feet of height and 25% coverage.
Its yards are then 50 feet front, 30 feet to one side with 70 feet for both sides, and 50 feet rear.
Cluster development is a special use on at least 5 acres, with lots to 0.2296 acre, 70 feet of width, 100 feet of depth, 35% coverage and yards of 25 feet front, 10 feet side and 15 feet rear.

ADUs vs. short-term rentals in Delaware

Short-term rentals allowed with local rules for Town of Delaware. Renting a home short term in the Town of Delaware requires an annual license under the town's short term rental ordinance, Chapter 175, in effect since April 10, 2024. Budget for the license renewal every year. These are separate questions from whether you can build an ADU — a unit you're allowed to add isn't automatically one you're allowed to rent nightly, so check both.

Good to know

Residential lot minimum0.92–1.84 ac — an ADU still has to fit the district's lot and setback envelope.
UtilityNYSEG territory.
Zoning codeecode360.com/DE3566
Building dept(845) 887-5250

ADU FAQ — Delaware, NY

Are ADUs allowed in Delaware, NY?

Town of Delaware has 7 districts. All districts prohibit ADUs. Check your address with the free ADU checker, or confirm with the building department at (845) 887-5250.

Do I need a special permit for an ADU in Delaware?

No. No district in Town of Delaware permits an ADU, so there is no permit to apply for. Codes change, so verify with the building department at (845) 887-5250 before ruling it out.

Can I use an ADU as a short-term rental in Delaware?

Short-term rentals allowed with local rules for Town of Delaware. ADU occupancy and short-term-rental rules are separate: an ADU you can build isn't automatically one you can rent nightly. Confirm both before you count on STR income.

Run the free ADU check for your parcel →

What an ADU costs to build in Delaware

Permission is one question and budget is another. An 800 sq ft accessory unit here runs roughly $190k–250k at a standard finish, and the per-square-foot rate comes in above a full house because the kitchen, bath, panel and heating plant cost the same either way. See the full cost to build an ADU in Delaware, priced by size.

How we know this

Sections analyzed: Ch. 220 § 220-41 Conversion of dwellings; § 220-40 Two-family dwellings; § 220-30A; § 220-11; § 220-9 and 220 Attachment 1 Schedule of District Regulations
Districts confirmed: 7 of 7 — every mapped district.
Last reviewed: 2026-10-07
Not covered here: Overlay districts, the zoning map, and any conditions attached to an individual parcel. Size limits and owner-occupancy terms sit in the code section above, not in this summary.

More on Delaware: Full zoning for new construction · ADU build cost · House build cost · ADU rules across Sullivan County · All Sullivan County towns

ADU information for Town of Delaware is compiled from the municipal code (last reviewed 2026-10-07) and provided for decision-support only — not legal or architectural advice. ADU eligibility, size, owner-occupancy and permit conditions vary by district and often carry exceptions; verify with the building department at (845) 887-5250 before relying on any answer. Source: the Offsite / Aldo zoning dataset.