ADU · Columbia County
Can you build an ADU in Hillsdale, NY?
Town of Hillsdale has 3 districts. All districts allow ADUs with occupancy restrictions. Check your address to confirm the district that applies to your parcel:
What the Hillsdale 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 | 3 ac | 50 / 50 / 100 ft | 35 ft | Occupancy restricted |
| Hamlet | 1 ac | 25 / 30 / 20 ft | 35 ft | Occupancy restricted |
| Hamlet Business | 1 ac | 40 / 50 / 100 ft | 35 ft | Occupancy restricted |
Rural — THE BASE ROW IS THE CONVENTIONAL COLUMN. The front setback recorded is the TOWN OR COUNTY ROAD figure; on a STATE road it is 70 ft and on a PRIVATE road 30 ft. A lot must also contain a SQUARE of minimum dimension 200 ft — a buildable-square requirement separate from lot area, width and frontage, and one with no field. The coverage figure is MAXIMUM IMPERMEABLE SURFACE, not building coverage. Minimum road frontage is 200 ft on a town or county road, 300 ft on a state road and 100 ft on a private road. Dimensional and setback requirements are applied IN LIGHT OF the siting guidelines in Appendixes I and II, and where the two conflict the guidelines are consulted (§ 245-21). In the Hamlet District the Planning Board may permit more than one building or use on a single lot. See § 245-27 for supplementary dimensional regulations and § 245-66 for existing nonconforming lots.
Hamlet — THE BASE ROW IS THE CONVENTIONAL COLUMN. The front setback recorded is the TOWN OR COUNTY ROAD figure; on a STATE road it is 40 ft. HM is the only district with a front-yard MAXIMUM as well — 40 ft on a town or county road and 80 ft on a state road. A lot must also contain a SQUARE of minimum dimension 100 ft — a buildable-square requirement separate from lot area, width and frontage, and one with no field. The coverage figure is MAXIMUM IMPERMEABLE SURFACE. Minimum road frontage is 100 ft on a town or county road and 200 ft on a state road. Dimensional and setback requirements are applied IN LIGHT OF the siting guidelines in Appendixes I and II, and where the two conflict the guidelines are consulted (§ 245-21). In the Hamlet District the Planning Board may permit more than one building or use on a single lot. See § 245-27 for supplementary dimensional regulations and § 245-66 for existing nonconforming lots.
Hamlet Business — HB has a single column — no conventional/cluster split. The front setback recorded is the TOWN OR COUNTY ROAD figure; on a STATE road it is 50 ft. A lot must also contain a SQUARE of minimum dimension 400 ft — a buildable-square requirement separate from lot area, width and frontage, and one with no field. Lot size and density in HB are further governed by § 245-26. The coverage figure is MAXIMUM IMPERMEABLE SURFACE. Minimum road frontage is 100 ft on a town or county road and 400 ft on a state road. Dimensional and setback requirements are applied IN LIGHT OF the siting guidelines in Appendixes I and II, and where the two conflict the guidelines are consulted (§ 245-21). In the Hamlet District the Planning Board may permit more than one building or use on a single lot. See § 245-27 for supplementary dimensional regulations and § 245-66 for existing nonconforming lots.
ADUs vs. short-term rentals in Hillsdale
Short-term rentals allowed with local rules for Town of Hillsdale. Local law adopted December 10, 2019 regulates all Transient Rentals (under 30 days); requires a $50 Special Permit from the ZBA and a $150 Certificate of Occupancy from the Building Inspector. 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 minimum1–3 ac — an ADU still has to fit the district's lot and setback envelope.
- UtilityNYSEG territory.
- Zoning codeecode360.com/HI4009
- Building dept(518) 325-5073
- Last reviewed2026-06-02
ADU FAQ — Hillsdale, NY
Are ADUs allowed in Hillsdale, NY?
Town of Hillsdale has 3 districts. All districts allow ADUs with occupancy restrictions. Check your address with the free ADU checker, or confirm with the building department at (518) 325-5073.
Do I need a special permit for an ADU in Hillsdale?
No district in Town of Hillsdale requires a special-use permit for an ADU - 3 districts allow ADUs with occupancy restrictions. Site-plan review or a building permit may still apply.
Can I use an ADU as a short-term rental in Hillsdale?
Short-term rentals allowed with local rules for Town of Hillsdale. 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 Hillsdale
Permission is one question and budget is another. An 800 sq ft accessory unit here runs roughly $195k–260k 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 Hillsdale, priced by size.
More on Hillsdale: Full zoning for new construction · ADU build cost · House build cost · All Columbia County towns
ADU information for Town of Hillsdale is compiled from the municipal code (last reviewed 2026-06-02) 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 (518) 325-5073 before relying on any answer. Source: Offsite / Aldo zoning dataset, municipalData.js.