ADU · Greene County

Can you build an ADU in Athens, NY?

Village of Athens has 8 districts. 5 districts prohibit ADUs, 2 require a special-use permit, 1 allows them with occupancy restrictions. Check your address to confirm the district that applies to your parcel:

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What the Athens code says

An accessory apartment is allowed in RL, RR and RM, between 320 and 800 square feet. Either the apartment or the house must be owner-occupied, so it cannot be a second rental. RL and RR need a special use permit; RM needs only site plan review.

Conditions the code attaches:

Either the accessory apartment or the single-family dwelling must be owner-occupied, so both units cannot be let (§ 250-25B(2)(h) and (3)(g)).
The unit must be between 320 and 800 square feet whether it is inside the house or in an accessory structure (§ 250-25B(2)(c) and (3)(d)).
A unit inside the house is limited to two bedrooms and may make no exterior change that alters or extends the existing foundation (§ 250-25B(2)(a), (d)).
In RM the use is listed among the permitted uses subject to site plan review, not among the special uses, so no special use permit is needed there.
One accessory apartment per single-family dwelling and per lot, and it may never be subdivided off the parcel (§ 250-25B(1)(e), (f)).
A unit in an accessory structure needs Department of Health approval of the water supply and sanitary system before a building permit, and may not be in a mobile home (§ 250-25B(3)(e), (f)).
Parking is one space for the apartment and two for the house when it is inside the dwelling, and two per dwelling unit when it is a separate structure (§ 250-25B(2)(f), (3)(c)).
No accessory apartment is listed among the uses for OSC, CR, C, MU/W or W.

How big an ADU can be in Athens

Size limits are set per district, and a unit inside the house is a different standard from a detached one. These are the figures the code publishes.

Inside the principal dwelling

320 to 800 sq ft of total square footage

RL, RR, RM · owner-occupancy required · § 250-25B(2)(c), (h)

Detached

320 to 800 sq ft of total square footage

RL, RR, RM · owner-occupancy required · § 250-25B(3)(d), (g)

What the Athens 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 Conservation District	—	—	25 ft	No
Residential Low-Density District	3 ac	20 / 20 / 20 ft	30 ft	Special permit
Recreational Residential District	3 ac	20 / 10 / 20 ft	30 ft	Special permit
Residential Medium-Density District	0.32 ac	20 / 10 / 20 ft	30 ft	Occupancy restricted
Commercial Residential District	—	—	35 ft	No
Commercial District	0.46 ac	- / 15 / 15 ft	35 ft	No
Mixed Use Waterfront District	0.46 ac	25 / 25 / 25 ft	35 ft	No
Waterfront District	5 ac	10 / 25 / 25 ft	25 ft	No

Residential Low-Density District - The 3 acre minimum applies only where there is neither public water nor sewer. With both public water and sewer, the minimum lot drops to 20,000 square feet (0.4591 acre) on 100 ft of lot width.

With public water but no sewer, the minimum lot is 1.5 acres, and the 150 ft lot width still applies.
The 20 ft front, side and rear yards and the 30 ft height stay the same at every level of water and sewer service.
An accessory structure is limited to 21 ft in height, against 30 ft for the main building.

Recreational Residential District - The 3 acre minimum applies where there is neither public water nor public sewer. With both public water and sewer, the minimum lot drops to 14,000 square feet (0.3214 acre) on 100 ft of width rather than 150 ft.

With public water but no sewer, the minimum lot is 1.5 acres and the 150 ft lot width still applies.
An accessory structure is limited to 21 ft in height, against 30 ft for the main building.

Residential Medium-Density District - Both a single-family and a two-family dwelling are permitted. The minimum lot size of 14,000 square feet applies whatever service reaches the lot, with no smaller figure for lots on public water or sewer.

An accessory structure is limited to 21 ft in height, against 30 ft for the main building.
The 10 ft side yard is the figure for one side.

Commercial Residential District - No lot area, lot width or setback figures are set for this district. Each of those must instead be compatible with surrounding properties, a judgment the Planning Board makes on site plan review.

The schedule allows replacement in kind.
Since the dimensions turn on what neighbouring properties look like rather than on published numbers, confirm what will be accepted with the village before designing.

Commercial District - The front yard is not a set dimension in the C district: the schedule calls for a front yard compatible with the area, so depth follows what neighbouring buildings do. Confirm the expected front yard with the building department before designing.

Single-family and two-family dwellings are permitted here alongside the commercial uses.
The minimum lot area is stated in the code as 20,000 square feet.

Mixed Use Waterfront District - Every use in this district goes through site plan review, so meeting the figures shown is only the starting point for approval.

Where a special use permit is required, § 250-33 sets additional standards for the waterfront and mixed use waterfront districts.

Waterfront District - Where public water and sewer serve the lot, the waterfront minimum drops to 14,000 square feet (0.3214 acre) on 75 ft of width; without them the five acres on 150 ft shown here is what binds.

The 25 ft rear yard is measured from the mean high water line, not from a lot line, so the river rather than the boundary sets it.
Single-family homes are allowed only under § 210-34 and only with site plan review.
The district is otherwise for waterfront-dependent uses, marinas, restaurants with river access and public recreation.

ADUs vs. short-term rentals in Athens

Short-term rentals allowed with local rules for Village of Athens. Short term rentals are allowed in all of the village's zoning districts, subject to registration. An annual permit is required, so factor the yearly renewal into the numbers. 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 minimum0.32–3 ac — an ADU still has to fit the district's lot and setback envelope.
UtilityCentral Hudson territory.
Zoning codeecode360.com/12637168
Building dept(518) 945-0601

ADU FAQ — Athens, NY

Are ADUs allowed in Athens, NY?

Village of Athens has 8 districts. 5 districts prohibit ADUs, 2 require a special-use permit, 1 allows them with occupancy restrictions. Check your address with the free ADU checker, or confirm with the building department at (518) 945-0601.

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

It depends on the district: 2 of 8 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 Athens?

Short-term rentals allowed with local rules for Village of Athens. 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.

Run the free ADU check for your parcel →

What an ADU costs to build in Athens

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 Athens, priced by size.

How we know this

Sections analyzed: Ch. 250 Attachment 1 Summary of Zoning Regulations (amended 5-13-2015 by L.L. No. 3-2015 and 3-24-2021 by L.L. No. 2-2021), Permitted Uses and Special Uses columns; § 250-25B Accessory apartments (1) general, (2) in the dwelling, (3) in an accessory structure
Districts confirmed: 8 of 8 — every mapped district.
Last reviewed: 2026-10-01
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 Athens: Full zoning for new construction · ADU build cost · House build cost · ADU rules across Greene County · All Greene County towns

ADU information for Village of Athens is compiled from the municipal code (last reviewed 2026-10-01) 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) 945-0601 before relying on any answer. Source: the Offsite / Aldo zoning dataset.