ADU · Albany County

Can you build an ADU in Colonie, NY?

Village of Colonie has 7 districts. 5 districts allow ADUs with occupancy restrictions, 2 do not. Check your address to confirm the district that applies to your parcel:

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What the Colonie code says

An accessory apartment is allowed on a special permit from the Planning Commission in Residential A, Residential B, Residential C, Commercial A and Commercial B. It is not allowed in Conservation/Residential or in Commercial D.

Conditions the code attaches:

The owner has to live in the dwelling unit the apartment is accessory to, so the principal house cannot be let out.
The apartment may be no more than 600 square feet with no more than one bedroom, and it is for occupancy by no more than two persons.
It has to sit inside a structure holding a dwelling of at least 900 square feet, so a detached garage or barn cannot hold one.
One apartment per lot, and the lot needs at least 75 feet of frontage and 100 feet of depth.
One additional parking space is required and all the spaces have to be grouped together.
The exterior has to keep the one-family character of the building, the code's own example being that only one front door will face the street.

What the Colonie 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
Conservation/Residential	1 ac	25 / 10 / 25 ft	35 ft	No
Commercial A	0.92 ac	25 / 10 / 25 ft	40 ft	Occupancy restricted
Commercial B	0.92 ac	25 / 10 / 25 ft	80 ft	Occupancy restricted
Commercial D	—	45 / 25 / 45 ft	35 ft	No
Residential A	0.22 ac	25 / 10 / 25 ft	35 ft	Occupancy restricted
Residential B	—	—	45 ft	Occupancy restricted
Residential C	0.22 ac	25 / 10 / 25 ft	—	Occupancy restricted

Conservation/Residential - At least 50% of the lot has to be left in its natural state as a conservation area, with a minimum dimension of 125 ft. That is a floor on undisturbed land rather than a ceiling on building coverage.

One single-family or two-family dwelling on a lot of at least one acre is allowed by right; more than that takes a special permit.
For a nonresidential use, impervious surface is capped at 12.5% of the site.
Maximum height is three storeys or 35 ft, whichever is less.
The maximum horizontal building dimension is 175 ft, or 150 ft and four units for a row of attached single-family dwellings.
Two buildings on one lot have to stand 20 ft apart side by side and 50 ft apart front to back.
Yards are measured from the edge of the Patroon Creek drainageway rather than the lot line, and land inside the drainageway still counts toward lot area and density.

Commercial A - A gasoline station carries its own site standards whatever the district figures say: at least 200 ft of street frontage and 200 ft of depth, and no site within 1,000 ft of another gasoline station on the same side of the highway.

An odd-shaped site may be considered with 200 ft of frontage and 40,000 sq ft of area.
No driveway may connect to a curb cut within 200 ft of a residential district boundary.

Commercial B - A gasoline station carries the same site standards here as in Commercial A: at least 200 ft of frontage and 200 ft of depth, and a 1,000 ft separation from another station on the same side of the highway.

Commercial D - Where this district abuts a residential district, a landscaped buffer strip at least 100 ft wide is required, and up to 50% of the required green space may count toward it.

Maximum height is two storeys or 35 ft, whichever is less, so the storey count can bind before the height does.

Residential A - The 10 ft side yard is a floor, not the whole rule. Under § 242-5 a house adds five feet to it for each floor of height, so a three-storey house needs 25 ft, and a corner lot keeps 25 ft from the side street line.

A two-family needs 15,625 sq ft (0.3587 acre) and 125 ft of frontage against a one-family's 9,375 sq ft and 75 ft, and § 242-5 forbids placing one on a lot portion under 125 ft wide.
Where the 125 ft depth is impracticable, a one-family lot may be shallower if it still holds 9,375 sq ft, and a two-family lot may go to 100 ft deep if it holds 12,500 sq ft.
A dwelling must hold at least 900 sq ft of finished floor area and must cover at least 900 sq ft of ground.
An accessory garage or shed of one storey and up to 576 sq ft may sit 5 ft from a side or rear lot line.

Residential B - Density here is set by planned occupancy rather than by a lot-area rate. The unit mix has to satisfy up to 25% of units at 2.5 persons and a 900 sq ft minimum, up to 25% at 2.0 persons and 750 sq ft, and up to 100% at 1.5 persons and 600 sq ft.

No multifamily building may exceed 45 ft or three storeys.
No multifamily building may stand within 200 feet of any Residential A property line.
A row of single-family attached dwellings may not exceed six units or 150 ft of horizontal dimension, and each unit or separately conveyed parcel must be at least 20 ft wide.
Fire lanes between buildings must be 25 ft plus 5 ft for each floor of the adjoining buildings.

Residential C - The 10 ft side yard is a floor, not the whole rule. Under § 242-5 a house adds five feet to it for each floor of height, so a three-storey house needs 25 ft, and a corner lot keeps 25 ft from the side street line.

Ordinary residential use here follows the Residential A standards: § 242-7A(1) permits the uses of § 242-5 subject to all of that section's restrictions, regulations, requirements and procedures.
What this district adds is the mobile home park. An individual site inside one must hold 5,000 sq ft and be at least 50 ft wide and 100 ft deep.
Front, rear and side yards, both for an individual site and for the park as a whole, are as approved by the Planning Commission.
A mobile home must be at least 14 ft wide, and its minimum living space is whatever HUD approves.

ADUs vs. short-term rentals in Colonie

Short-term rentals allowed with local rules for Village of Colonie. Renting a home short term here needs a short-term rental permit and an annual registry update, under the Village Building Department's requirements. 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 minimum0.22–1 ac — an ADU still has to fit the district's lot and setback envelope.
UtilityNational Grid territory.
Zoning codeecode360.com/CO0033
Building dept(518) 869-7562

ADU FAQ — Colonie, NY

Are ADUs allowed in Colonie, NY?

Village of Colonie has 7 districts. 5 districts allow ADUs with occupancy restrictions, 2 do not. Check your address with the free ADU checker, or confirm with the building department at (518) 869-7562.

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

No district in Village of Colonie requires a special-use permit for an ADU - 5 districts allow ADUs with occupancy restrictions, 2 do not. Site-plan review or a building permit may still apply.

Can I use an ADU as a short-term rental in Colonie?

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

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 Colonie, priced by size.

How we know this

Sections analyzed: Ch. 242 Zoning: § 242-3 Definitions (apartment, accessory; two-family dwelling); § 242-4 Conservation-Residential; § 242-5 Residential A (A(4), A(6), F, G, I); § 242-6 Residential B; § 242-7 Residential C; § 242-8 Commercial A; § 242-9 Commercial B; § 242-10 Commercial D; § 242-12 Special permits
Districts confirmed: 7 of 7 — every mapped district.
Last reviewed: 2026-09-09
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 Colonie: Full zoning for new construction · ADU build cost · House build cost · ADU rules across Albany County · All Albany County towns

ADU information for Village of Colonie is compiled from the municipal code (last reviewed 2026-09-09) 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) 869-7562 before relying on any answer. Source: the Offsite / Aldo zoning dataset.