ADU · Rockland County
Can you build an ADU in Hillburn, NY?
Village of Hillburn has 8 districts. All districts prohibit ADUs. Check your address to confirm the district that applies to your parcel:
What the Hillburn code says
Hillburn's zoning makes no provision for an accessory dwelling unit in any district. Under § 250-15C, accessory uses and structures must be clearly incidental and subordinate to the principal use of the lot, and cannot be established before a principal use or building.
Conditions the code attaches:
- § 250-15D allows an accessory use on a lot without a principal use only in narrow cases, and states no residence shall be established on the separate property except in compliance with the chapter.
- That allowance requires an adjoining or across-the-street lot within 100 feet, in the same ownership, accessory to a one-family detached residence in existence on the chapter's effective date.
- Limits there include noncommercial use, no more than two operable vehicles parked, no more than 500 square feet of impervious paving, and no accessory building exceeding one story or 15 feet.
- In a building holding more dwellings than the bulk rules allow, the number of dwellings may not be increased above the number in existence on the effective date of the zoning chapter.
- The Transit-Oriented Development overlay provides for multiple-family units as principal dwellings in a planned development, not as accessory units.
- Confirm current requirements with the village building department at (845) 357-2036 before counting on a second unit.
What the Hillburn 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 |
|---|---|---|---|---|
| Open Space | 5.51 ac | 75 / 50 / 100 ft | 35 ft | No |
| Residence | 1.38 ac | 50 / 40 / 75 ft | 35 ft | No |
| Residence | 0.21 ac | 25 / 10 / 30 ft | 35 ft | No |
| Residence | 0.14 ac | 25 / 10 / 30 ft | 35 ft | No |
| Local Shopping | 0.23 ac | 25 / 20 / 25 ft | 25 ft | No |
| General Commercial | 0.23 ac | 25 / 20 / 25 ft | 25 ft | No |
| Regional Economic Development | 0.46 ac | 25 / 20 / 25 ft | 25 ft | No |
| Light Industry | 0.92 ac | 35 / 50 / 50 ft | 25 ft | No |
Open Space - Hillburn sets bulk per use, not per district, and the figures shown are the row for a park or playground. Public utility lines and rights-of-way serving the immediate neighbourhood are permitted by right on the same figures.
- Utility lines and rights-of-way that do not serve the immediate neighbourhood need a special use permit and site plan approval, on the same figures.
- Accessory buildings have their own required distances, measured to the principal building, the front street, the side street, the exterior side lot line and the rear lot line.
Residence - The side setbacks must add to at least 100 ft, so 40 ft on each side falls twenty feet short. Hillburn sets bulk per use, so the figures shown are one row among several.
- A place of worship, a community facility, a fire, police or ambulance building or a public utility substation shares one row, by special use permit with site plan approval.
- That row's yards are deeper than a house's on every side: 200 ft of width, 75 ft in front, 50 ft to each side with 125 ft for the pair and 100 ft to the rear.
- An animal sanctuary is possible by special use permit, on three acres with a two-hundred-foot width.
- Accessory buildings have their own required distances, measured to the principal building, the front street, the side street, the exterior side lot line and the rear lot line.
Residence - The side setbacks must add to at least 30 ft, so 10 ft on each side falls ten feet short. Hillburn sets bulk per use, so the figures shown are one row among several.
- A two-family house needs 0.2755 acres on 120 ft of width, with 15 ft to each side and 40 ft for the pair, by special use permit with site plan approval.
- An assisted living facility is the one thing in this village allowed three storeys and 40 ft; everything else in a residence district stops at two and a half storeys and 35 ft.
- It needs 2 acres on 125 ft of width with 50 ft to every line and 100 ft for the pair of sides, and may cover 50% of the lot at a 0.5 floor area ratio, by special use permit.
- A place of worship, a community facility, a fire, police or ambulance building or a public utility substation shares a further row, by special use permit.
- That row needs 0.5051 acres on 125 ft of width, with 35 ft in front, 25 ft to each side, 60 ft for the pair and 50 ft to the rear.
- Accessory buildings have their own required distances, measured to the principal building, the front street, the side street, the exterior side lot line and the rear lot line.
Residence - On a lot of the 50 ft minimum width, the 10 ft side setbacks on each side leave thirty feet for the building. Hillburn sets bulk per use, so the figures shown are one row among several.
- A two-family house needs only two thousand square feet more than a one-family house, 0.1837 acres, with the same 50 ft of width, yards, height and coverage, by special use permit.
- A place of worship, a community facility, a fire, police or ambulance building or a public utility substation shares a further row, by special use permit.
- That row needs 0.5051 acres on 125 ft of width, with 35 ft in front, 8 ft to each side, 20 ft for the pair and 30 ft to the rear.
- Accessory buildings have their own required distances, measured to the principal building, the front street, the side street, the exterior side lot line and the rear lot line.
Local Shopping - The figures shown are the smallest of six tiers and cover only small shopfronts, such as a retail shop, bar, delicatessen, take-out restaurant, laundromat or personal service shop. Other uses have their own rows.
- A sit-down restaurant needs fifteen thousand square feet on a hundred feet of width, with forty percent coverage.
- A museum or a professional or medical office needs twenty thousand square feet on a hundred and twenty-five feet of width, at fifty percent coverage and a floor area ratio of 0.25.
- A commercial recreation use, grocery store, health and fitness facility or designed shopping centre needs forty thousand square feet on two hundred feet of width, 35 ft front and 50 ft each side.
- A heavier group, including automobile sales, a building contractor, a hotel, a cinema, a pharmacy and a warehouse, needs twenty thousand square feet on a hundred and fifty feet of width.
- Only that heavier group may reach three storeys and 35 ft, at a floor area ratio of 0.5.
- Where a use in that heavier group abuts a residence district, its 25 ft side and rear setbacks double to 50 ft and the combined side requirement rises by half.
General Commercial - The figures shown are the smallest of six tiers and only a delicatessen sits on them; every other use in the district has its own row.
- An automotive garage, building contractor, retail landscape materials yard, microbrewery or woodworking shop needs fifteen thousand square feet on a hundred feet of width, at forty percent coverage.
- A business, professional or medical office needs twenty thousand square feet on a hundred and twenty-five feet of width.
- Public utility distribution and substations need twenty-two thousand square feet, with an eight-foot side setback.
- A dry-cleaning depot, health and fitness facility, laboratory, light industry, commercial recreation use or wholesale warehouse needs forty thousand square feet on two hundred feet of width.
- A concrete mixing facility needs a hundred and twenty thousand square feet, with 75 ft to each side and 75 ft for the pair.
- Accessory buildings have their own required distances, measured to the principal building, the front street, the side street, the exterior side lot line and the rear lot line.
Regional Economic Development - The figures shown cover a day spa, a medical or professional office, tourism-related retail and a tourism-related winery. An antique shop or art gallery needs only ten thousand square feet on 75 ft of width, at thirty-five percent coverage and a ratio of 0.15.
- A sit-down restaurant needs fifteen thousand square feet.
- A commercial recreation use, health and fitness facility or designed shopping centre needs forty thousand square feet on two hundred feet of width.
- A bus depot, conference centre, cultural and performing arts centre, resort hotel or museum needs eighty thousand square feet on two hundred feet of width, with 50 ft to every line.
- Those uses need a hundred feet for the pair of side setbacks and may reach three storeys and 45 ft.
- Accessory buildings have their own required distances, measured to the principal building, the front street, the side street, the exterior side lot line and the rear lot line.
Light Industry - The figures shown cover light industry, a laboratory or research facility, commercial recreation, a health and fitness facility and a wholesale warehouse; all but the fitness facility need a special use permit as well as site plan approval.
- A building contractor or retail landscape materials yard needs fifteen thousand square feet on a hundred feet of width, 25 ft to the front, rear and each side, at forty percent coverage.
- A business, professional or medical office is permitted by right on twenty thousand square feet and a hundred and twenty-five feet of width, the least land any use needs here without a special permit.
- Public utility distribution and substations need twenty-two thousand square feet with an eight-foot side setback, and are the only rows here allowed two and a half storeys and 35 ft.
- Accessory buildings have their own required distances, measured to the principal building, the front street, the side street, the exterior side lot line and the rear lot line.
ADUs vs. short-term rentals in Hillburn
Short-term rentals allowed with local rules for Village of Hillburn. Short-term rentals are regulated in the Village of Hillburn. The zoning chapter defines the use at § 250-7, and Chapter 188, Rental Properties, carries a rental permit requirement at § 188-8. 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 minimum0.14–1.38 ac — an ADU still has to fit the district's lot and setback envelope.
- UtilityOrange & Rockland territory.
- Zoning codeecode360.com/15367578
- Building dept(845) 357-2036
ADU FAQ — Hillburn, NY
Are ADUs allowed in Hillburn, NY?
Village of Hillburn has 8 districts. All districts prohibit ADUs. Check your address with the free ADU checker, or confirm with the building department at (845) 357-2036.
Do I need a special permit for an ADU in Hillburn?
No. No district in Village of Hillburn permits an ADU, so there is no permit to apply for. Codes change, so verify with the building department at (845) 357-2036 before ruling it out.
Can I use an ADU as a short-term rental in Hillburn?
Short-term rentals allowed with local rules for Village of Hillburn. 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 Hillburn
Permission is one question and budget is another. An 800 sq ft accessory unit here runs roughly $225k–295k 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 Hillburn, priced by size.
How we know this
- Zoning code
- ecode360.com/15367578
- Districts confirmed
- 8 of 8 — every mapped district.
- Last reviewed
- 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 Hillburn: Full zoning for new construction · ADU build cost · House build cost · ADU rules across Rockland County · All Rockland County towns
ADU information for Village of Hillburn is compiled from the municipal code (last reviewed 2026-07-21) 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) 357-2036 before relying on any answer. Source: the Offsite / Aldo zoning dataset.