ADU · Dutchess County
Can you build an ADU in Washington, NY?
Town of Washington has 9 districts. 7 districts allow ADUs with a special-use permit, 1 does not. 1 district has incomplete data - verify with the building department at (845) 677-3419. Check your address to confirm the district that applies to your parcel:
What the Washington 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 |
|---|---|---|---|---|
| Rural Residential 10-Acre | 10 ac | 100 / 100 / 75 ft | 35 ft | Special permit |
| Rural Residential Special 10-Acre | 10 ac | 100 / 100 / 75 ft | 35 ft | Special permit |
| Low Density Residential 5-Acre | 5 ac | 100 / 75 / 75 ft | 35 ft | Special permit |
| Low Density Residential Special | 5 ac | 100 / 75 / 75 ft | 35 ft | Special permit |
| Medium Density Residential 2-Acre | 2 ac | 75 / 50 / 50 ft | 35 ft | Special permit |
| High Density Residential 1-Acre | 1 ac | 50 / 30 / 25 ft | 35 ft | Special permit |
| Hamlet Mixed-Use | 1 ac | 50 / 30 / 25 ft | 35 ft | Special permit |
| Land Conservation | 10 ac | 100 / 100 / 75 ft | 15 ft | No |
| Hamlet (floating district) | 0.25 ac | 20 / 15 / 25 ft | 35 ft | — |
Rural Residential 10-Acre — Height is capped twice over: 2 1/2 stories and 35 ft. Minimum road frontage is 400 ft, published as its own column beside the lot width. For rear lot frontages see § 165-68.
Rural Residential Special 10-Acre — Height is capped twice over: 2 1/2 stories and 35 ft. Minimum road frontage is 400 ft, published as its own column beside the lot width. For rear lot frontages see § 165-68. RS-10 shares a single schedule column with RR-10.
Low Density Residential 5-Acre — Height is capped twice over: 2 1/2 stories and 35 ft. Minimum road frontage is 300 ft, published as its own column beside the lot width. For rear lot frontages see § 165-68.
Low Density Residential Special — Height is capped twice over: 2 1/2 stories and 35 ft. Minimum road frontage is 300 ft, published as its own column beside the lot width. For rear lot frontages see § 165-68. RS-5 shares a single schedule column with RL-5.
Medium Density Residential 2-Acre, High Density Residential 1-Acre — Height is capped twice over: 2 1/2 stories and 35 ft. Minimum road frontage is 200 ft, published as its own column beside the lot width. For rear lot frontages see § 165-68.
Hamlet Mixed-Use — Appendix B publishes TWO complete columns for HM. The base row here is the residential one. A NON-RESIDENTIAL use in the same district is governed by the other column: half an acre rather than one, 100 ft of lot width rather than 200, an 80 ft front yard, a 15 ft side yard, a 50 ft rear yard and 60% coverage rather than 10%. Height is capped twice over: 2 1/2 stories and 35 ft for a residential use; the non-residential column states no storey limit, only the 35 ft. Minimum road frontage is 100 ft, published as its own column beside the lot width. For rear lot frontages see § 165-68.
Land Conservation — Height is capped twice over: 1 story and 15 ft — the lowest in the Town. Minimum road frontage is 400 ft, published as its own column beside the lot width. For rear lot frontages see § 165-68.
Hamlet (floating district) — H is a FLOATING district under § 165-13: Appendix B publishes a full column of standards for it, but the district is not on the Zoning Map until the Town Board maps one, at which point it replaces the previous use classification. The setbacks above are minimums and the district also sets MAXIMUMS — a front yard of no more than 50 ft and a side yard of no more than 50 ft, which are build-to limits rather than setbacks; the rear yard has no maximum (Note 2). The quarter-acre minimum is a floor only: § 165 Appendix B Note 1 requires such greater area as the Dutchess County Department of Health demands, which on an unsewered lot is usually a great deal more. Height is capped twice over: 2 1/2 stories and 35 ft. Minimum road frontage is 50 ft, published as its own column beside the lot width. For rear lot frontages see § 165-68.
ADUs vs. short-term rentals in Washington
Short-term rentals allowed with local rules for Town of Washington. Short-term rentals require a Town permit under Chapter 115, Rentals, Short-Term, adopted 1-31-2024 by L.L. No. 1-2024. § 115-3 makes the permit mandatory and caps how many may be issued, § 115-4 sets the application requirements and § 115-5 the operating standards. § 115-2 presumes a dwelling unit is an STR from advertising, so listing the property is itself evidence of the use. 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 Washington at (845) 677-3419 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 minimum0.25–10 ac — an ADU still has to fit the district's lot and setback envelope.
- UtilityCentral Hudson territory.
- Zoning codeecode360.com/37495610
- Building dept(845) 677-3419
- Last reviewed2026-08-16
ADU FAQ — Washington, NY
Are ADUs allowed in Washington, NY?
Town of Washington has 9 districts. 7 districts allow ADUs with a special-use permit, 1 does not. 1 district has incomplete data - verify with the building department at (845) 677-3419. Check your address with the free ADU checker.
Do I need a special permit for an ADU in Washington?
It depends on the district: 7 of 9 require a special-use permit, the rest do not. Check the district that applies to your parcel before you design.
Can I use an ADU as a short-term rental in Washington?
Short-term rentals allowed with local rules for Town of Washington. 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 Washington
Permission is one question and budget is another. An 800 sq ft accessory unit here runs roughly $210k–275k 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 Washington, priced by size.
More on Washington: Full zoning for new construction · ADU build cost · House build cost · All Dutchess County towns
ADU information for Town of Washington is compiled from the municipal code (last reviewed 2026-08-16) 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) 677-3419 before relying on any answer. Source: Offsite / Aldo zoning dataset, municipalData.js.