ADU · Greene County

Can you build an ADU in Lexington, NY?

Town of Lexington has 3 districts. 2 districts allow ADUs with a special-use permit, 1 does not. Check your address to confirm the district that applies to your parcel:

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What the Lexington code says

An accessory dwelling unit requires a special permit from the Planning Board in H and RR, and is prohibited in C. Attached, detached and converted units all qualify, with a limit of one accessory unit per lot.

Conditions the code attaches:

Floor area must be less than 35% of the one-family dwelling's floor area or 600 square feet, whichever is less, and the unit may have no more than two bedrooms (§ 5.14).
The owner must occupy at least one of the dwelling units on the lot, and no clause limits who may occupy the accessory unit.
On a private well, certified potable water and adequate flow are required, plus Greene County Department of Health testing before a building permit and annually after that.
Sewage capacity for two units must be certified, and no special permit is issued where the County Department of Health determines the water or sewage system cannot handle the added demand.
Failure to test, or to correct water quality problems, can revoke the special permit.
An accessory unit may be used as a short term rental if it holds a valid Town of Lexington STR permit and complies with the STR regulations (§ 5.14.A.13).

What the Lexington 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
Hamlet District	0.69 ac	45 / 25 / 25 ft	35 ft	Special permit
Rural Residential District	3 ac	75 / 30 / 30 ft	35 ft	Special permit
Conservation District	10 ac	75 / 45 / 100 ft	35 ft	No

Hamlet District - The 45 foot front yard is measured from the center line of the road, not from the front lot line. A building here may not exceed a footprint of 4,000 square feet, whatever the 20% coverage figure would allow on a larger lot.

Minimum lot size is 30,000 square feet (0.6887 acre).
Minimum road frontage is 35 feet, or 25 feet on a flag or rear lot, which is a separate requirement from the 100 foot minimum lot width.
Height is measured from the sill of the first floor, and a basement does not count as a story.
The floodplain and stream corridor overlays do not change these figures unless the zoning law says so.

Rural Residential District - The 75 foot front yard is measured from the center line of the road, not from the front lot line. A building here may not exceed a footprint of 4,000 square feet, whatever the 10% coverage figure would allow on a larger lot.

Minimum road frontage is 35 feet, or 25 feet on a flag or rear lot, which is a separate requirement from the 300 foot minimum lot width.
This district is all land below 2,400 feet above mean sea level that is not in the Hamlet District, so elevation decides which district a parcel falls in.
Height is measured from the sill of the first floor, and a basement does not count as a story.
The floodplain and stream corridor overlays do not change these figures unless the zoning law says so.

Conservation District - The 75 foot front yard is measured from the center line of the road, not from the front lot line. A building here may not exceed a footprint of 3,000 square feet, whatever the 5% coverage figure would allow on a 10 acre lot.

Minimum road frontage is 35 feet, or 25 feet on a flag or rear lot, which is a separate requirement from the 500 foot minimum lot width.
This district is all land above 2,400 feet above mean sea level, and may also take conservation land below that line.
Most of this land is owned by the Department of Environmental Conservation as part of Catskill Park, or by the New York City Department of Environmental Protection as watershed.
Height is measured from the sill of the first floor, and a basement does not count as a story.
The floodplain and stream corridor overlays do not change these figures unless the zoning law says so.

ADUs vs. short-term rentals in Lexington

Short-term rentals allowed with local rules for Town of Lexington. Short term rentals need a town permit. All 62 non-resident owner permits are issued, with 0 available and about 5 applicants on the waiting list, so an owner who does not live in the town cannot get a permit now. There is no cap on resident owner permits. 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. Municipal source

Good to know

Residential lot minimum0.69–3 ac — an ADU still has to fit the district's lot and setback envelope.
UtilityCentral Hudson territory.
Zoning codewww.lexingtonny.com/DocumentCenter/View/467/Town-of-Lexington-Zoning-Law-Adopted--final-draft
Building dept(518) 989-6476

ADU FAQ — Lexington, NY

Are ADUs allowed in Lexington, NY?

Town of Lexington has 3 districts. 2 districts allow ADUs with a special-use permit, 1 does not. Check your address with the free ADU checker, or confirm with the building department at (518) 989-6476.

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

It depends on the district: 2 of 3 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 Lexington?

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

Permission is one question and budget is another. An 800 sq ft accessory unit here runs roughly $195k–255k 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 Lexington, priced by size.

How we know this

Sections analyzed: Zoning Law of the Town of Lexington § 4.02 Use Table and legend; § 4.01 closed list; § 5.14 Accessory Dwelling Units; Art. II definitions
Districts confirmed: 3 of 3 — every mapped district.
Last reviewed: 2026-10-05
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 Lexington: Full zoning for new construction · ADU build cost · House build cost · ADU rules across Greene County · All Greene County towns

ADU information for Town of Lexington is compiled from the municipal code (last reviewed 2026-10-05) 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) 989-6476 before relying on any answer. Source: the Offsite / Aldo zoning dataset.