ADU · Ulster County
Can you build an ADU in Denning, NY?
Town of Denning has 3 districts. All districts allow ADUs. Check your address to confirm the district that applies to your parcel:
What the Denning 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 |
|---|---|---|---|---|
| H Hamlet District | 1 ac | 25 / 20 / 30 ft | 35 ft | As of right |
| R Rural District | 5 ac | 40 / 25 / 40 ft | 35 ft | As of right |
| P Provincial District | 10 ac | 40 / 25 / 40 ft | 35 ft | As of right |
H Hamlet District — Schedule note 2 applies the minimum lot area to EACH DWELLING, so the district figure is land per unit. Minimum road frontage 50 ft on a town road and 50 ft on a county road. THE LOT AREA IS NOT ENOUGH ON ITS OWN: § 270A requires a minimum DEVELOPMENT ENVELOPE of 33,000 contiguous square feet in the Hamlet District — a buildable area excluding wetlands, watercourses, conservation buffers, floodways, slopes over 25%, parts of the lot under 51 ft wide and easement-encumbered land — with a minimum horizontal dimension of 50 ft in any direction. Front yard is measured from the abutting right-of-way or street line, except where that right-of-way is under 50 ft wide, from a line 25 ft from and parallel to its centre line (schedule note 5). Schedule note 3 tolerates a lot up to 0.2 acre (8,712 sq ft) under the minimum to absorb modern survey corrections, but no more than one such lot in any subdivision. It is an allowance, not a second standard, so no reduced figure is recorded.
R Rural District — Schedule note 2 applies the minimum lot area to EACH DWELLING, so the district figure is land per unit. Minimum road frontage 100 ft on a town road and 100 ft on a county road. § 270A requires a minimum DEVELOPMENT ENVELOPE of 50,000 square feet of buildable land, excluding wetlands, watercourses, conservation buffers, floodways, slopes over 25%, parts of the lot under 51 ft wide and easement-encumbered land, with a minimum horizontal dimension of 50 ft. Front yard is measured from the abutting right-of-way or street line, except where that right-of-way is under 50 ft wide, from a line 25 ft from and parallel to its centre line (schedule note 5). Schedule note 3 tolerates a lot up to 0.2 acre (8,712 sq ft) under the minimum to absorb modern survey corrections, but no more than one such lot in any subdivision. It is an allowance, not a second standard, so no reduced figure is recorded.
P Provincial District — Schedule note 2 applies the minimum lot area to EACH DWELLING, so the district figure is land per unit. Minimum road frontage 150 ft on a town road and 100 ft on a county road. § 270A requires a minimum DEVELOPMENT ENVELOPE of 50,000 square feet of buildable land, excluding wetlands, watercourses, conservation buffers, floodways, slopes over 25%, parts of the lot under 51 ft wide and easement-encumbered land, with a minimum horizontal dimension of 50 ft. Front yard is measured from the abutting right-of-way or street line, except where that right-of-way is under 50 ft wide, from a line 25 ft from and parallel to its centre line (schedule note 5). Schedule note 3 tolerates a lot up to 0.2 acre (8,712 sq ft) under the minimum to absorb modern survey corrections, but no more than one such lot in any subdivision. It is an allowance, not a second standard, so no reduced figure is recorded.
ADUs vs. short-term rentals in Denning
No local short-term-rental law on record - which is not the same as permission for Town of Denning. No local short-term-rental law found as of 2026-08-26; the Town Zoning Law (2019) was read in full and contains no short-term-rental, transient-rental or rental-registration provision. What it does regulate is a related use: § 525 permits an owner-occupied one-family dwelling to be converted to a BED AND BREAKFAST ESTABLISHMENT — 'transient housing accommodation less than one month in length' — ON A SPECIAL USE PERMIT, capped at five sleeping rooms and ten transient lodgers, with no sleeping rooms above the second story and breakfast served only to those occupying the transient quarters. That is an owner-present lodging use and does not reach an unhosted whole-house rental. Absence of a found STR law is not permission. New York State's 2025 short-term rental registry (Ch. 99 of the Laws of 2025) separately requires every host statewide to register the unit regardless of local law. Confirm with Town of Denning at (845) 985-2285 before listing. 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 minimum1–5 ac — an ADU still has to fit the district's lot and setback envelope.
- UtilityCentral Hudson territory.
- Zoning codewww.denningny.gov/wp-content/uploads/2023/05/TOD-ZONING-LAW-2019.pdf
- Building dept(845) 985-2285
- Last reviewedApr 2026
ADU FAQ — Denning, NY
Are ADUs allowed in Denning, NY?
Town of Denning has 3 districts. All districts allow ADUs. Check your address with the free ADU checker, or confirm with the building department at (845) 985-2285.
Do I need a special permit for an ADU in Denning?
No district in Town of Denning requires a special-use permit for an ADU - 3 districts allow ADUs. Site-plan review or a building permit may still apply.
Can I use an ADU as a short-term rental in Denning?
No local short-term-rental law on record - which is not the same as permission for Town of Denning. 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.
What an ADU costs to build in Denning
Permission is one question and budget is another. An 800 sq ft accessory unit here runs roughly $200k–265k 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 Denning, priced by size.
More on Denning: Full zoning for new construction · ADU build cost · House build cost · All Ulster County towns
ADU information for Town of Denning is compiled from the municipal code (last reviewed Apr 2026) 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) 985-2285 before relying on any answer. Source: Offsite / Aldo zoning dataset, municipalData.js.