ADU · Sullivan County

Can you build an ADU in Rockland, NY?

Town of Rockland has 5 districts. All districts allow ADUs with occupancy restrictions. Check your address to confirm the district that applies to your parcel:

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What the Rockland code says

Town-wide, the only accessory unit is a temporary mother-daughter apartment inside a single-family home, allowed wherever a single-family dwelling is permitted. It cannot be rented out: occupancy is limited to a dependent relative of the principal occupants.

Conditions the code attaches:

One bedroom maximum, and the apartment must be inside the single-family dwelling, so a detached unit is not available.
The occupant must be a relative who depends at least partially on the principal occupants for the activities of daily living.
No separate accessory apartment is listed in the schedule of district regulations, and § 185-11 states any use not listed is prohibited. Each district also allows one primary dwelling per lot.
A second unit is available as a two-family dwelling, a principal permitted use in RC, R1, R2, NB and GB. Under § 185-13A it ordinarily requires the equivalent of two minimum sized lots in lot area.
Minimum habitable area is 450 sq ft per dwelling unit in a single- or two-family dwelling.
For how these limits apply to a specific house, check with the building department at (845) 439-5450.

What the Rockland 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 Conservation District	5 ac	50 / 50 / 100 ft	35 ft	Occupancy restricted
Low-Density Residential District	1 ac	20 / 25 / 40 ft	30 ft	Occupancy restricted
Moderate- to High-Density Residential District	0.25 ac	20 / 15 / 30 ft	35 ft	Occupancy restricted
Neighborhood Business District	0.23 ac	30 / 20 / 30 ft	35 ft	Occupancy restricted
General Business District	—	10 / 5 / 0 ft	40 ft	Occupancy restricted

Rural Conservation District - A lot here needs 5 acres and an average width of 300 feet. A building sits 50 feet back from the front line, 50 feet from each side and 100 feet from the rear, reaches 35 feet, and hard surface may cover 10% of the lot.

Each dwelling unit in a single or two family dwelling needs at least 450 square feet of habitable area, and a lot may hold only one primary dwelling.
A two family dwelling ordinarily requires the equivalent of two minimum sized lots in lot area, because the standards apply to each dwelling unit.
A yard bordering a lake, stream or body of water runs at least 50 feet from the high water mark, and at least 100 feet in a subdivision approved after § 185-15D was adopted.
Private community central water and wastewater systems are prohibited outside an existing municipal or central water or sewer district.
A conservation subdivision is available in this district under § 185-24, and the Planning Board may modify the chapter to accommodate it.
A residential lot needs a front lot line at least 50 feet long, which is frontage rather than the average lot width the schedule asks for.

Low-Density Residential District - A lot here needs 1 acre and an average width of 100 feet. A building sits 20 feet back from the front line, 25 feet from each side and 40 feet from the rear, reaches 30 feet, and hard surface may cover 50% of the lot.

Each dwelling unit in a single or two family dwelling needs at least 450 square feet of habitable area, and a lot may hold only one primary dwelling.
A two family dwelling ordinarily requires the equivalent of two minimum sized lots in lot area, because the standards apply to each dwelling unit.
A yard bordering a lake, stream or body of water runs at least 50 feet from the high water mark, and at least 100 feet in a subdivision approved after § 185-15D was adopted.
Private community central water and wastewater systems are prohibited outside an existing municipal or central water or sewer district.
The district is meant for single-family and two-family dwellings in parts of town without public sewer services.
A residential lot needs a front lot line at least 50 feet long, which is frontage rather than the average lot width the schedule asks for.

Moderate- to High-Density Residential District - A lot here needs 0.25 acres and an average width of 75 feet. A building sits 20 feet back from the front line, 15 feet from each side and 30 feet from the rear, reaches 35 feet, and hard surface may cover 60% of the lot.

Each dwelling unit in a single or two family dwelling needs at least 450 square feet of habitable area, and a lot may hold only one primary dwelling.
A two family dwelling ordinarily requires the equivalent of two minimum sized lots in lot area, because the standards apply to each dwelling unit.
A yard bordering a lake, stream or body of water runs at least 50 feet from the high water mark, and at least 100 feet in a subdivision approved after § 185-15D was adopted.
Private community central water and wastewater systems are prohibited outside an existing municipal or central water or sewer district.
The district is meant for moderate-to-high-density residential development in parts of town with public sewer capacity.
A residential lot needs a front lot line at least 50 feet long, which is frontage rather than the average lot width the schedule asks for.

Neighborhood Business District - A lot here needs 10,000 square feet, which is 0.2296 acres, and an average width of 75 feet. A building sits 30 feet back from the front line, 20 feet from each side and 30 feet from the rear, reaches 35 feet, and hard surface may cover 60% of the lot.

Each dwelling unit in a single or two family dwelling needs at least 450 square feet of habitable area, and a lot may hold only one primary dwelling.
A two family dwelling ordinarily requires the equivalent of two minimum sized lots in lot area, because the standards apply to each dwelling unit.
Single-family, two-family and multifamily dwellings are principal permitted uses here and take the same standards as the commercial ones.
A yard bordering a lake, stream or body of water runs at least 50 feet from the high water mark, and at least 100 feet in a subdivision approved after § 185-15D was adopted.
Private community central water and wastewater systems are prohibited outside an existing municipal or central water or sewer district.

General Business District - The schedule asks for no minimum lot area and no rear yard in this district. An average lot width of 30 feet, a 10 foot front yard and a 5 foot side yard apply, a building reaches 40 feet, and hard surface may cover 90% of the lot.

Each dwelling unit in a single or two family dwelling needs at least 450 square feet of habitable area, and a lot may hold only one primary dwelling.
Single-family, two-family and multifamily dwellings are principal permitted uses here and take the same standards as the business ones.
A two family dwelling ordinarily requires the equivalent of two minimum sized lots in lot area, because the standards apply to each dwelling unit.
A yard bordering a lake, stream or body of water runs at least 50 feet from the high water mark, and at least 100 feet in a subdivision approved after § 185-15D was adopted.
Private community central water and wastewater systems are prohibited outside an existing municipal or central water or sewer district.

ADUs vs. short-term rentals in Rockland

Short-term rentals allowed with local rules for Town of Rockland. Short term rentals are permitted in all zoning districts where residential dwellings are allowed, under a local law adopted July 6, 2023. Owners must apply at Town Hall and pass a safety inspection. 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 minimum0.25–5 ac — an ADU still has to fit the district's lot and setback envelope.
UtilityNYSEG territory.
Zoning codeecode360.com/RO1679
Building dept(845) 439-5450

ADU FAQ — Rockland, NY

Are ADUs allowed in Rockland, NY?

Town of Rockland has 5 districts. All districts allow ADUs with occupancy restrictions. Check your address with the free ADU checker, or confirm with the building department at (845) 439-5450.

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

No district in Town of Rockland requires a special-use permit for an ADU - 5 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 Rockland?

Short-term rentals allowed with local rules for Town of Rockland. 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.

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What an ADU costs to build in Rockland

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 Rockland, priced by size.

How we know this

Sections analyzed: Ch. 185 § 185-7 definition of dwelling, single-family; § 185-11 closed list; § 185-13A two-family lot area; Appendix 1 Schedule of District Regulations (Supp 3, Mar 2026, through L.L. No. 2-2025)
Districts confirmed: 5 of 5 — 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 Rockland: 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 Rockland 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) 439-5450 before relying on any answer. Source: the Offsite / Aldo zoning dataset.