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ADU · Albany County

Are ADUs allowed in Albany County, NY?

There is no county-wide answer. In New York an accessory dwelling unit is governed by the town, city or village — so the rule changes at every municipal line, and often between districts inside one town. Below is each of the 18 municipalities in Albany County, with what its zoning districts actually say.

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ADU rules by municipality in Albany County

Can you build an ADU in Albany, NY?

16 districts allow ADUs with occupancy restrictions, 4 do not. 6 districts have incomplete data - verify with the building department at (518) 434-5165.

An accessory dwelling unit of up to 800 square feet is permitted by right beside a single-family house in every residential and mixed-use district. The owner must live in one of the two units. I-1, I-2 and LC take none.

§ 375-302 Permitted Use Table 375.302.1; § 375-301(1)(e); § 375-303(6)(a) Accessory dwelling unit; § 375-303(8) Residential conversions; § 375-206 Overlay districts Reviewed 2026-09-19 Full Albany ADU rules →

Can you build an ADU in Cohoes, NY?

7 districts allow ADUs with occupancy restrictions, 5 do not. 4 districts have incomplete data - verify with the building department at (518) 233-2127.

An accessory unit is allowed in MU-CC, MU-DC, MU-TC, MU-NC and MFR, and in R-1 and R-2 with a Planning Board special use permit. The owner must live in one of the two units. MU-1, MU-2, C-1, I-1 and LC take no accessory unit.

Schedule A, Schedule of Use Regulations (285 Attachment 1); § 285-5 Definitions (accessory dwelling, in-law apartment); § 285-34B Prohibited uses; § 285-65 Accessory dwelling units Reviewed 2026-09-19 Full Cohoes ADU rules →

Can you build an ADU in Watervliet, NY?

6 of 10 districts allow ADUs. 4 districts have incomplete data - verify with the building department at (518) 270-3800.

An attached or detached accessory dwelling unit of up to 900 square feet is permitted by right beside an existing single-family house, with no rule on who lives in either unit. It must sit at least 10 feet from the house and from every property line.

§ 272-19B(15) Accessory dwelling units (L.L. No. 5-2025); § 272-19A(3); § 272-17A(3); 272 Attachment 3 Schedule A Reviewed 2026-09-19 Full Watervliet ADU rules →

Can you build an ADU in Berne, NY?

7 of 9 districts prohibit ADUs. 2 districts have incomplete data - verify with the building department at (518) 872-1448.

Berne has no accessory apartment use. In RAF a house can be converted to an attached two-family with a special use permit, one per five acres, which changes it from a one-family house. A new two-family is allowed by right in MDR, NC, TN/MU1 and TN/MU2 but not GC.

§ 190-4 Names of zoning districts; § 190-7 Permitted uses; 190 Attachment 1 Schedule of Uses and its key; 190 Attachment 2 Density Control Schedule Reviewed 2026-09-20 Full Berne ADU rules →

Can you build an ADU in Bethlehem, NY?

11 districts allow ADUs with occupancy restrictions, 4 do not. 2 districts have incomplete data - verify with the building department at (518) 439-4955.

An accessory apartment is allowed by right in R and RLI and by Planning Board special use permit in RLL, RA-B, RB, RC, CR, RR, H, CH and RH. The owner must live in one of the two units. None in MR, C, ME or I.

§ 128-73 Accessory apartments; § 128-12 Districts established; § 128-14A; 128 Attachment 1 Schedule of Uses, accessory apartment row and note 6 Reviewed 2026-09-19 Full Bethlehem ADU rules →

Can you build an ADU in Coeymans, NY?

All districts prohibit ADUs.

Coeymans has no accessory apartment use. A second household means a two-family house, a principal use by right in R-2, R-3, R-4P, R-A and R-A1 and by special permit in R-1.

165 Attachment 5 Schedule of District Zoning Regulations; § 165-4 List of districts; § 165-7A Reviewed 2026-09-19 Full Coeymans ADU rules →

Can you build an ADU in Colonie, NY?

9 districts allow ADUs with occupancy restrictions, 2 do not. 4 districts have incomplete data - verify with the building department at (518) 783-2706.

A temporary accessory unit attached to the house is allowed in most districts, but only someone related to the owner-occupant, by family or its functional equivalent, may live in it. The permit ends on sale and the unit must then be removed. LC-C and CEM-C take none.

190 Attachment 1 Table of Permitted Uses and key; § 190-20A Prohibited uses; § 190-22 Dwelling unit, accessory; § 190-29 Overlay districts; § 190-16 Reviewed 2026-09-19 Full Colonie ADU rules →

Can you build an ADU in Guilderland, NY?

8 districts prohibit ADUs, 8 allow them with occupancy restrictions. 3 districts have incomplete data - verify with the building department at (518) 356-1980.

An accessory dwelling unit is a permitted use, with a building permit and yearly inspection rather than a board approval, in AGR, RA3, RA5, R10, R15, R20, R40 and BNRP. The owner has to live in one of the two units. Other districts take none.

§ 280-40G Accessory dwelling unit (L.L. No. 7-2019); § 280-11, § 280-12 and § 280-19 permitted-use lists; § 280-6; § A285-1 Fees Reviewed 2026-09-19 Full Guilderland ADU rules →

Can you build an ADU in Knox, NY?

8 of 9 districts prohibit ADUs. 1 district has incomplete data - verify with the building department at (518) 872-2551.

Knox has no accessory apartment use in any district. A second household means a two-family house, permitted by right in R-K, AG, B1, AM and MRD with no occupancy or size condition. LC-1 and LC-2 permit no dwelling.

Zoning Ordinance (through Amendment #14) Art IV § 40 Permitted Uses and key, § 41 Residential Uses, § 43 Accessory Uses; Art II § 20; Art III § 30, § 31 Reviewed 2026-09-19 Full Knox ADU rules →

Can you build an ADU in New Scotland, NY?

All districts prohibit ADUs.

New Scotland's zoning law has no accessory dwelling unit of any kind, in any district. The second-household route here is a two-family dwelling, a special use in seven districts and available by right in two of the three hamlet sub-districts.

Town of New Scotland LL No. 1 of 2020 (codification of Ch. 190), Appendix 1: § 190-5 Definitions (accessory use; dwelling unit; dwelling, two-family; congregate dwelling); § 190-6 Zoning Map and Districts; §§ 190-11 RF, 190-12 RA, 190-13 MDR, 190-14 R2, 190-15 RH, 190-16 CH, 190-17 COM, 190-18 IND, 190-19a MEDD, 190-19b Hamlet District; Art XIV §§ 190-102 to 190-104 Residential Senior Citizen Housing; Art XVI § 190-112 and Table 1 Permitted Uses; LL No. 4 of 2022 Reviewed 2026-09-09 Full New Scotland ADU rules →

Can you build an ADU in Rensselaerville, NY?

All districts allow ADUs with occupancy restrictions.

An accessory apartment is allowed in every district on a special use permit from the Planning Board, and it may sit inside the house, attached to it, or in a separate accessory structure. The owner has to live in one of the two units, and may live in either.

Town of Rensselaerville Zoning Law: Section 2 Definitions (Accessory Apartment; Accessory Structure); Art V Section 1 Use Requirements (Key Table, Key Codes, Residential Uses table); Art V Section 2 dimensional requirements; Section 12 Accessory Apartments A/B/C; Section 22 Hotel or Motel Establishments; Art IX special use permits Reviewed 2026-09-09 Full Rensselaerville ADU rules →

Can you build an ADU in Westerlo, NY?

2 districts allow ADUs, 1 does not.

Westerlo allows an accessory dwelling unit by right in RD/A and RH-W, at up to 1,200 sq ft of living space, with no owner-occupancy, kinship or age condition, and no bar on renting it out. A larger unit needs site plan approval and a special use permit.

Town of Westerlo Local Law No. 1 of 2025 (Accessory Dwelling Units): Accessory Dwelling Unit Defined, Amend Section 8.40, Amend Section 8.50, Effective Date. Town of Westerlo Zoning Law as consolidated in LL No. 1 of 2020: § 8.10 Establishment of Districts, § 8.40 Rural Development/Agricultural, § 8.50 Residential Hamlet (incl. subsec. 4), § 8.60 Light Industrial, Art 9 Site Plan Review Reviewed 2026-09-08 Full Westerlo ADU rules →

Can you build an ADU in Altamont, NY?

5 districts allow ADUs with occupancy restrictions, 5 require a special-use permit, 2 do not. 1 district has incomplete data - verify with the building department at (518) 861-8554.

An accessory apartment needs a Zoning Board of Appeals special use permit, and the owner must live in the house or the apartment. In R-40, R-20, R-15, RPO and RCD a house can instead be converted to a two-family by the same permit, with no such rule. None in R-10M or P.

§ 355-38K Accessory apartments and conversion of single-family to two-family residences; § 355-12; 355 Attachment 1 Use Schedule and its key Reviewed 2026-09-20 Full Altamont ADU rules →

Can you build an ADU in Colonie, NY?

5 districts allow ADUs with occupancy restrictions, 2 do not.

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.

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 Reviewed 2026-09-09 Full Colonie ADU rules →

Can you build an ADU in Green Island, NY?

5 of 6 districts prohibit ADUs. 1 district has incomplete data - verify with the building department at (518) 629-0368.

Green Island has no accessory apartment use, and a lot may carry only one residential building. A two-family house is permitted by right in R1-GI, R2-GI and C-GI, with no owner-occupancy or size condition.

169 Attachment 1 Schedule of Use Regulations; § 169-19 Use regulations; § 169-37 Limitation on number of dwellings per lot Reviewed 2026-09-19 Full Green Island ADU rules →

Can you build an ADU in Menands, NY?

8 districts prohibit ADUs, 7 require a special-use permit.

An in-law apartment needs a special use permit, and every one of the seven residential districts allows one. It must sit inside or attached to the single-family dwelling and may not have a separate entrance, so it cannot be entered independently of the main house.

§ 169-41.2 In-law apartments (Art 9); § 169-94B Definitions (in-law apartment); Art 2 district Special-use lists §§ 169-13 through 169-19 Reviewed 2026-09-09 Full Menands ADU rules →

Can you build an ADU in Ravena, NY?

All districts prohibit ADUs.

Ravena has no accessory apartment use. A second household means a two-family house, a principal use by right in R-2 and R-3P and by special permit in R-1. The business, industrial and community facility districts take no house.

119 Attachment 1 and Attachment 2, Schedule of District Zoning Regulations; § 119-4; § 119-7A; L.L. No. 4-2021 Reviewed 2026-09-19 Full Ravena ADU rules →

Can you build an ADU in Voorheesville, NY?

11 districts allow ADUs with a special-use permit, 3 do not.

An accessory apartment inside a house, or a cottage home in an accessory structure, needs a special use permit from the Planning Commission where allowed, and neither is available in MF, GB-V or I-V. A house standing when the zoning took effect can also become a two-family.

L.L. No. 2-2023 (Zoning, adopted 2023-02-15) at Drw 7 Land Use and Development, § 7-7 Zoning: Art II Definitions (accessory dwelling unit, accessory apartment, cottage home); Table 1 Table of Uses by District and its key; Art VII (M) Accessory Uses and Structures, subsections (2) Accessory Apartments and (3) Cottage Home; Table 1 row: Single Family Dwelling Existing at the Effective Date of the Zoning and Converted to Two-Family Dwelling Reviewed 2026-09-20 Full Voorheesville ADU rules →

ADU questions people ask about Albany County

Are ADUs allowed in Albany County?

There is no single county-wide answer — ADUs are governed by each town, city and village, not by the county. Of the 18 Albany County municipalities with mapped zoning districts, 12 allow an accessory dwelling unit in at least one district, and 2 allow one by right somewhere. The section for your municipality below gives the specific answer.

Does Albany County issue ADU permits?

No. Zoning approval and building permits both come from the municipality — the town, city or village — not the county. County health departments do commonly review septic and water supply for a new dwelling unit, which is often the binding constraint on a rural lot.

What size ADU can I build in Albany County?

Size caps are set per municipality and frequently per district, and they are one of the details most often stated wrongly by national ADU sites. Open your municipality's page below for the code sections analyzed, then confirm the current figure with the building department before you design to it.

What an ADU costs to build in Albany County

Permission and budget are separate questions. See the Albany County cost-to-build breakdown for current per-square-foot ranges — an accessory unit runs above a full house per square foot, because the kitchen, bath, panel and heating plant cost the same at any size.

Run the free ADU check for your parcel →

More on Albany County: Zoning for new construction by town · Cost to build · ADU rules across every county we cover

ADU information for Albany County is compiled from each municipality's own code , most recently reviewed 2026-09-20, and provided for decision-support only — not legal or architectural advice. Eligibility, size, owner-occupancy and permit conditions vary by district and often carry exceptions; confirm with the municipality before relying on any answer. 10 of the 18 municipalities below still have one or more districts that have not been analyzed, and each says so in its own section. Source: the Offsite / Aldo zoning dataset.

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