ADU · Erie County
Are ADUs allowed in Erie 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 44 municipalities in Erie County, with what its zoning districts actually say.
- 44municipalities with mapped districts
- 20allow an ADU in at least one district
- 2allow one by right somewhere
ADU rules by municipality in Erie County
Can you build an ADU in Buffalo, NY?
All districts allow ADUs.
Buffalo handles the accessory unit as a named building type. A carriage house is permitted in every district here, either as an ancillary building behind the principal structure or as a principal building on its own lot.
Can you build an ADU in Lackawanna, NY?
11 districts prohibit ADUs, 2 allow them with occupancy restrictions.
In SFR and MR a house may include an auxiliary unit for up to two members of the household, at least one aged 60 or over or disabled. It cannot be rented to anyone else. The commercial, industrial, open space and Bethlehem redevelopment districts permit no houses.
Can you build an ADU in Tonawanda, NY?
6 districts allow ADUs with occupancy restrictions, 4 do not.
The only accessory living space the City names is quarters for servants employed on the premises, allowed by right wherever a house is: R-1, R-2, R-C, C-1, C-2 and C-M. Whoever lives there has to work there. C-1A, the commerce park and the two industrial districts have none.
Can you build an ADU in Alden, NY?
All districts prohibit ADUs.
Alden has no accessory apartment or in-law unit in any district, and no provision for converting a house to add a unit. A second unit means building a two-family dwelling, which R-2, R-3 and R-C permit.
Can you build an ADU in Amherst, NY?
15 districts prohibit ADUs, 12 require a special-use permit.
An accessory dwelling unit inside a single-family detached house needs a special use permit, and is permitted in R-R, S-A, R-1, R-2, R-3, CR-3A, R-4, MFR-4A, MFR-5 and MFR-6. TR-3, MFR-7 and MHR-8 do not allow one.
Can you build an ADU in Aurora, NY?
7 districts allow ADUs with occupancy restrictions, 1 does not.
Aurora allows an in-law apartment inside a single-family house wherever a house is permitted, with no board approval. It is family housing: only a relative of the owner may live in it, and it cannot be rented.
Can you build an ADU in Boston, NY?
8 districts prohibit ADUs, 1 allows them with occupancy restrictions, 1 requires a special-use permit. 1 district has incomplete data - verify with the building department at (716) 941-6113.
An accessory apartment of 640 to 800 sq ft, made inside or as an addition to a single-family house, needs a special use permit in R-2 and R-C. The owner must live in one of the two units when applying. The other districts do not allow one.
Can you build an ADU in Brant, NY?
All districts prohibit ADUs.
Brant has no accessory apartment or in-law unit under any name. The second-unit route here is a two-family dwelling, which R-R, R-1, R-2 and A permit by right on a lot of at least one acre.
Can you build an ADU in Cheektowaga, NY?
All districts prohibit ADUs.
An accessory dwelling unit is not permitted in R, RS, RA, RSC or RMH. In R, a second unit means a two-family dwelling, which is allowed by right only in one part of the town and needs a Zoning Board of Appeals special permit outside it.
Can you build an ADU in Clarence, NY?
7 districts prohibit ADUs, 3 allow them with occupancy restrictions.
Clarence allows a secondary living unit added to a single-family house in A-FZ, A-RR and R-SF by special exception permit, but it can never be rented. Only a family member, a paid employee or a temporary guest of the owner may live there.
Can you build an ADU in Colden, NY?
All districts prohibit ADUs.
Colden has no accessory apartment or in-law unit. A second home on one lot has to be a principal dwelling: a two-family house or dwelling group in R-2, R-RB and C, and in AG a two-family house or two single-family houses on at least six acres.
Can you build an ADU in Collins, NY?
3 districts allow ADUs with occupancy restrictions, 1 does not.
Collins allows quarters for servants employed on the premises as a by-right accessory use in R, R-A and C, so only household staff may live there. A two-family house, permitted by right in the same districts, is the route to a rentable second unit. M allows no dwellings.
Can you build an ADU in Concord, NY?
14 of 15 districts prohibit ADUs. 1 district has incomplete data - verify with the building department at (716) 592-4946.
Concord has no accessory apartment or in-law unit in any district, and its January 2026 rewrite did not add one. A second unit means building a two-family house, which R-2, R-AG, R-RB, C-1, C-2, C-T and C-R permit by right.
Can you build an ADU in Eden, NY?
4 districts allow ADUs with occupancy restrictions, 2 do not. 2 districts have incomplete data - verify with the building department at (716) 992-3408.
Eden allows one accessory dwelling unit of at least 800 sq ft, attached or detached, by right in AP, RR, MFR and R2, if the owner lives in the main house. PK and LI do not allow one, though a dwelling that existed as a residence on May 11, 1977 may become a two-family by right.
Can you build an ADU in Elma, NY?
5 of 7 districts prohibit ADUs. 2 districts have incomplete data - verify with the building department at (716) 652-3260.
Elma has no accessory apartment or in-law unit. R-B and R-C allow a house to hold two families, which is the route to a second unit; R-A allows one family per lot, and C-3 and the Industrial Zone allow no houses.
Can you build an ADU in Evans, NY?
8 districts prohibit ADUs, 8 require a special-use permit. 1 district has incomplete data - verify with the building department at (716) 217-3500.
An auxiliary housing unit inside a single-family house needs a Board of Appeals special use permit, for up to two members of the family living there, at least one 60 or older, handicapped or otherwise unable to live independently. The business and industrial districts have none.
Can you build an ADU in Grand Island, NY?
18 of 19 districts prohibit ADUs. 1 district has incomplete data - verify with the building department at (716) 773-9600.
Grand Island has no accessory apartment or in-law unit in any district. A second unit means building a duplex, which R-3 and the North and South Business Districts permit; R-2 dropped the duplex in 2016.
Can you build an ADU in Hamburg, NY?
21 districts prohibit ADUs, 1 allows them with occupancy restrictions.
Hamburg has no accessory apartment provision under any name. The one second dwelling in the town is in R-E: on a lot of three or more acres, a residence for a caretaker employed on the premises, or a guest house for occasional use by friends of the occupant.
Can you build an ADU in Holland, NY?
All districts prohibit ADUs.
Holland has no accessory dwelling provision under any name, in any district. The route to a second unit is a two-family dwelling: a principal use by right in R-1 and R-2, and a special permit use in R-A, the rural and agricultural district.
Can you build an ADU in Lancaster, NY?
All districts prohibit ADUs.
Lancaster has no accessory apartment, accessory dwelling unit or in-law provision in any district, and a use the code does not specifically list is not allowed. The route to a second unit is MF, where two-family dwellings and multifamily housing are principal uses.
Can you build an ADU in Marilla, NY?
All districts prohibit ADUs.
Marilla has no accessory dwelling unit of any kind, in A, R-R, M-H, B, B-1 or I. In A and R-R a two-family dwelling is permitted by right instead, and what it costs is land rather than approval.
Can you build an ADU in Newstead, NY?
All districts prohibit ADUs.
Newstead has no accessory apartment. Where houses are allowed a lot with twice the district minimum area (90,000 sq ft in R-A) can carry two houses, and R-A, R-2, R-3, R-C and MHP allow two-family houses. The commercial, industrial and RV districts have no such route.
Can you build an ADU in North Collins, NY?
All districts prohibit ADUs.
North Collins has no accessory apartment. A second unit in a house makes it a two-family house, allowed by right in R-A, R-2, R-C, C-1 and C-2 but not R-1. R-2, R-C, C-1 and C-2 also allow two houses on a lot with a Town Board site plan.
Can you build an ADU in Orchard Park, NY?
All districts prohibit ADUs.
Orchard Park has no accessory apartment or in-law unit. R-3 and R-4 allow two-family houses, on no more than a third of the lots in a subdivision. A-1, R-1 and R-2 allow a one-family dwelling as their only dwelling, and no district lets an existing house add a unit.
Can you build an ADU in Sardinia, NY?
All districts prohibit ADUs.
Sardinia has no accessory dwelling unit of any kind, in AR, HR, HB, LC, BL or GCF. AR and HR permit a two-family dwelling by right instead, with no special use permit, no owner-occupancy condition and no size ratio.
Can you build an ADU in Tonawanda, NY?
4 districts prohibit ADUs, 3 allow them with occupancy restrictions, 3 require a special-use permit.
An accessory dwelling unit or in-law suite needs a special permit in R-1, R-2 and MR, is allowed by right in MU-N, MU-GC and MU-W, and is not allowed in MU-I, GI, CF or OS. The owner must live in one of the dwellings as their primary residence.
Can you build an ADU in Wales, NY?
The only district prohibits ADUs.
Wales has no accessory dwelling provision: no accessory building may be occupied as a dwelling, and a garage or other accessory building may not be used for living quarters unless it is attached to a dwelling.
Can you build an ADU in West Seneca, NY?
All districts prohibit ADUs.
West Seneca has no accessory apartment. The letter A in the district name is what matters: R-90, R-75 and R-65 allow a single-family house only, while R-90A, R-75A, R-65A, R-50, R-100A, R-60A, C-1 and C-2 allow a two-family house by right.
Can you build an ADU in Akron, NY?
All districts prohibit ADUs.
The village has no accessory apartment or in-law unit in any district. A second unit means building a two-family house, which R-2 and R-3 permit.
Can you build an ADU in Alden, NY?
4 districts prohibit ADUs, 4 allow them with occupancy restrictions.
The only accessory living space allowed is quarters for servants employed on the premises, by right in R-O, R-1, R-2 and R-C. Occupancy is tied to employment on the property, so it carries no open-market rent.
Can you build an ADU in Angola, NY?
3 districts prohibit ADUs, 3 require a special-use permit.
An auxiliary housing unit of up to 1,000 sq ft inside a single-family house needs a Village Board special use permit in R-1, MF-R and MU-R. The owner must live in the house or the unit, and the permit is renewed every two years. MU-B and I have no such unit.
Can you build an ADU in Blasdell, NY?
All districts prohibit ADUs.
Blasdell has no accessory apartment. In R-2, the two-family district, an existing building can be converted into more dwelling units by right, which changes the use of the house rather than adding a subordinate unit.
Can you build an ADU in Depew, NY?
6 districts prohibit ADUs, 1 allows them with occupancy restrictions, 1 requires a special-use permit.
Depew allows an auxiliary housing unit inside a single-family house in R-1 and R-2 by special permit, but only for elderly or disabled members of the family living there, so it cannot be rented. C-1, C-2, MS, M-1 and M-2 have no such unit.
Can you build an ADU in East Aurora, NY?
6 districts prohibit ADUs, 4 require a special-use permit.
East Aurora allows one accessory dwelling unit with no more than one bedroom beside a single-family house, by special use permit, in SFR, LDR, GR and LCR. The owner must live on the property and file a notarized affidavit; a buyer who keeps renting must file a new one.
Can you build an ADU in Farnham, NY?
All districts prohibit ADUs.
No accessory apartment in any district. A two-family house is allowed by right in all three districts, with each unit at least 800 sq ft and the average unit at least 920 sq ft. The commercial and industrial districts also allow apartments in a building with a business.
Can you build an ADU in Gowanda, NY?
7 of 8 districts prohibit ADUs. 1 district has incomplete data - verify with the building department at (716) 532-3353.
Gowanda has no accessory apartment or in-law unit in any district. A second unit means building a two-family house, allowed by right in R-2 and R-3; in R-2 each unit needs at least 800 sq ft.
Can you build an ADU in Hamburg, NY?
5 districts prohibit ADUs, 3 require a special-use permit.
An accessory dwelling unit is allowed only in LCR, NCC and GC, and only with a special use permit. It is prohibited in SFR, TVR and VCC, and MU-R and MU-I allow neither a house nor such a unit.
Can you build an ADU in Kenmore, NY?
8 of 9 districts prohibit ADUs. 1 district has incomplete data - verify with the building department at (716) 873-5700.
Kenmore has no accessory apartment in any district. Residential district 1 allows a one-family house and a garage, district 2 adds a two-family house, district 3 apartment houses, and industrial land can carry any of them. The school, business and office districts add nothing.
Can you build an ADU in Lancaster, NY?
6 districts prohibit ADUs, 4 allow them with occupancy restrictions.
Quarters for servants employed upon the premises are a permitted accessory use in R-1, R-2, R-2A and C-1. Occupancy is tied to employment on the property, so it carries no open-market rent.
Can you build an ADU in North Collins, NY?
All districts prohibit ADUs.
No district here has an accessory apartment or in-law unit. In R-1 and R-2 the route to a second unit is a special permit from the Board of Appeals to convert a house that already stood when the chapter was adopted, and R-3 and RM permit a two-family dwelling outright.
Can you build an ADU in Orchard Park, NY?
All districts prohibit ADUs.
No district here has an accessory apartment. R-3, R-4, B-1, B-2 and I-1 instead allow a second principal building on a lot with a special use permit, and R-3, R-4 and B-2 allow a two-family house. R-1 and R-2 allow one house on a lot and nothing more.
Can you build an ADU in Sloan, NY?
All districts prohibit ADUs.
Sloan has no accessory apartment or in-law unit in any district. A second unit means a two-family house, permitted by right in R, RA, RC, M1 and M2; in R it needs a lot of at least 9,000 sq ft and 70 feet wide, 80 feet on a corner.
Can you build an ADU in Springville, NY?
3 districts prohibit ADUs, 3 allow them with occupancy restrictions.
An accessory dwelling unit is permitted in R-8.5, R-6 and RM, and at least one dwelling unit on the parcel must be occupied by one or more owners as a permanent residence. B-1, VI and CIP have none.
Can you build an ADU in Williamsville, NY?
4 districts allow ADUs, 3 allow them with occupancy restrictions.
In R-1, R-2 and R-3 an accessory apartment earns no rent: only a relative of the family, or one employee, may live in it, and the owner must have lived there five years before applying. It takes a Zoning Board permit and must be re-approved when the house sells.
ADU questions people ask about Erie County
Are ADUs allowed in Erie County?
There is no single county-wide answer — ADUs are governed by each town, city and village, not by the county. Of the 44 Erie County municipalities with mapped zoning districts, 20 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 Erie 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 Erie 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 Erie County
Permission and budget are separate questions. See the Erie 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.
More on Erie County: Zoning for new construction by town · Cost to build · ADU rules across every county we cover
ADU information for Erie County is compiled from each municipality's own code , most recently reviewed 2026-09-16, 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. 8 of the 44 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.