ADU · Monroe County
Are ADUs allowed in Monroe 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 30 municipalities in Monroe County, with what its zoning districts actually say.
- 30municipalities with mapped districts
- 18allow an ADU in at least one district
- 1allow one by right somewhere
ADU rules by municipality in Monroe County
Can you build an ADU in Rochester, NY?
All districts prohibit ADUs.
Rochester's zoning code creates no accessory dwelling unit. A second unit is treated as a principal use, so it is only possible where the code allows a two-family or multifamily dwelling.
Can you build an ADU in Brighton, NY?
All districts prohibit ADUs.
Brighton's code does not allow an accessory apartment, accessory dwelling unit or in-law unit in any residential district; under § 201-12 any use the regulations do not list is prohibited.
Can you build an ADU in Chili, NY?
All districts prohibit ADUs.
Chili's zoning code provides for no accessory apartment or accessory dwelling unit. The only second-unit route is a two-family dwelling or duplex, which is a principal building rather than an accessory unit and needs a special use permit from the Planning Board.
Can you build an ADU in Clarkson, NY?
All districts allow ADUs with a special-use permit.
An accessory dwelling unit, governed by § 140-23.4, needs a special permit in all three residential districts. It may be a detached structure in AR and RS-20, but in RS-10 it must be located within the primary structure.
Can you build an ADU in Gates, NY?
3 districts allow ADUs with occupancy restrictions, 2 do not.
In R-1-15, R-1-11 and R-1-8, an in-law area or apartment inside a one-family house is a permitted accessory use. It may be occupied only by a resident member of the family that lives in the house, or by an in-law of that family.
Can you build an ADU in Greece, NY?
8 districts prohibit ADUs, 4 allow them with occupancy restrictions.
Greece has no general accessory dwelling unit allowance. The residential route is one in-law apartment per one-family dwelling, and it is occupancy restricted to a relative by marriage of the resident family, so it is not a unit that can be rented on the open market.
Can you build an ADU in Hamlin, NY?
5 districts allow ADUs with occupancy restrictions, 1 does not.
One apartment inside a single-family house is permitted with a special use permit from the Planning Board, and the owner has to live in the house. The code sets no size cap, and the apartment's parking uses the house's driveway.
Can you build an ADU in Henrietta, NY?
All districts prohibit ADUs.
Henrietta's code includes no accessory dwelling unit, and its residential use lists are closed: any use not enumerated is prohibited in the R residential districts. The closest route to a second unit is a two-family dwelling in R-2-15, by Town Board special use permit.
Can you build an ADU in Irondequoit, NY?
All districts allow ADUs with a special-use permit.
In R-1, R-2, R-3 and R-R, one additional in-law dwelling unit, attached or detached, is allowed only with a special use permit from the Town Board. Planning Board site plan approval under Article XV is also required.
Can you build an ADU in Mendon, NY?
All districts prohibit ADUs.
Mendon has no accessory dwelling unit. Its only second-unit route is converting an existing building in RS-30, with a Planning Board special use permit, which creates co-equal dwellings; RA-5, RA-2 and RA-1 are one dwelling per lot.
Can you build an ADU in Ogden, NY?
9 districts prohibit ADUs, 1 allows them with occupancy restrictions.
In R-1 only, an in-law apartment is a conditional use that needs a permit from the Zoning Board of Appeals. Only the owners of record and their blood relatives may live in it, so it cannot be rented on the open market.
Can you build an ADU in Parma, NY?
5 districts allow ADUs with a special-use permit, 3 do not.
An accessory apartment is permitted by special use permit from the Zoning Board of Appeals in AR, RR, NR, MR and WR, under § 165-23. It is not available in the two mixed-use districts or in Light Industrial.
Can you build an ADU in Penfield, NY?
6 districts allow ADUs with occupancy restrictions, 2 do not.
Penfield allows one in-law apartment inside a single-family home in its six single-family districts, under § 250-5.1D(1). It may be occupied only by family or in-laws of the household, never rented to anyone else, and the permission ends on a change of ownership.
Can you build an ADU in Perinton, NY?
All districts prohibit ADUs.
No accessory dwelling unit is allowed, and an accessory building may not be lived in. In B and C an existing one-family house can be converted to a two-family by special permit from the Zoning Board of Appeals, which creates two full dwellings.
Can you build an ADU in Pittsford, NY?
All districts prohibit ADUs.
Pittsford does not allow a separate accessory dwelling unit. It does allow an accessory suite (§ 185-113A(8)), a division of the primary residence added to or created within a single-family dwelling that shares living space and a shared entrance with it.
Can you build an ADU in Riga, NY?
The only district allows ADUs with a special-use permit.
An in-law apartment is permitted in the RRA district as a special use through the Planning Board. Its size, occupancy and whether it may be rented to an unrelated tenant are not confirmed, so confirm with the Building Inspector before counting on renting it.
Can you build an ADU in Rush, NY?
3 districts prohibit ADUs, 3 require a special-use permit.
Accessory apartments are a special permit use in R-20, R-30 and RR-5. The conditions that govern one, such as floor area, occupancy, owner occupancy, parking and whether it may be detached, are not confirmed, so ask Code Enforcement before sizing a unit.
Can you build an ADU in Sweden, NY?
All districts prohibit ADUs.
Sweden's code has no accessory apartment, in-law unit or accessory dwelling unit, and its one-family districts allow one dwelling. Extra units are contemplated only in MR-1, the multiple residence district, at no more than 12 dwelling units per acre under § 175-39.
Can you build an ADU in Webster, NY?
4 districts allow ADUs with occupancy restrictions, 2 do not.
An accessory apartment is permitted in R-1, R-2, R-3 and LL under § 350-50, one per lot, and one or more of the owners of record must live in the principal dwelling unit. MHR and LMR are not eligible.
Can you build an ADU in Wheatland, NY?
All districts prohibit ADUs.
Wheatland has no accessory dwelling unit. Its route to a second unit is converting a one-family house to a two-family, a special exception use in AR-2, R-24, R-16 and R-12 that goes to the Planning Board and creates two full dwellings. RA prohibits it.
Can you build an ADU in East Rochester, NY?
All districts prohibit ADUs.
No accessory dwelling unit, accessory apartment or in-law unit is provided for in R-1-70, R-1-48 or TR. In R-1-70 and R-1-48, a special use permit can legalize an owner-occupied two-family dwelling constructed or converted before the zoning restrictions.
Can you build an ADU in Brockport, NY?
The only district prohibits ADUs.
No accessory apartment is allowed in O (O Residential Use District), the village's only residential district. The uses listed there do not include a second dwelling unit.
Can you build an ADU in Churchville, NY?
2 districts allow ADUs with a special-use permit, 1 does not.
An accessory dwelling unit needs a special permit in LDR and TVR, and MDR has no accessory dwelling unit route. Its floor area, owner occupancy, parking and whether it may be detached are not confirmed.
Can you build an ADU in Fairport, NY?
All districts allow ADUs.
One accessory dwelling unit per lot per single-family dwelling is permitted by right in RLD, RN and RTN, up to 650 sq ft and one bedroom. It must be fully enclosed within or attached to the existing principal structure; detached units are prohibited.
Can you build an ADU in Hilton, NY?
1 district prohibits ADUs, 1 requires a special-use permit.
An accessory dwelling unit is a special permitted use in the R district, so it needs site approval from the Village under Article IV and is not allowed by right. Its floor area, owner occupancy, parking and whether it may be detached are not confirmed.
Can you build an ADU in Honeoye Falls, NY?
3 districts allow ADUs with a special-use permit, 1 does not.
An accessory unit of up to two bedrooms needs a special permit in R-1, R-2 and R-4, and the owner must live on the lot. R-3 has none; there a house of at least 2,000 sq ft can be converted to three or more full dwellings by right.
Can you build an ADU in Pittsford, NY?
2 districts prohibit ADUs, 2 require a special-use permit.
An accessory unit needs a special use permit, in LDR and in R-5, where it goes over a garage and is capped at 750 sq ft. One unit must be the owner's principal residence, sworn by affidavit and renewed on each sale. MDR and LOR allow none.
Can you build an ADU in Scottsville, NY?
3 districts allow ADUs with a special-use permit, 2 do not.
An accessory dwelling unit of 300 to 800 sq ft needs a special permit in R1-16, R1-12 and R1-6, and the owner must live on the lot. Converting a house of at least 2,400 sq ft to a two-family needs a special permit in all five districts and creates two full dwellings.
Can you build an ADU in Spencerport, NY?
The only district allows ADUs with occupancy restrictions.
Spencerport's code has an in-law apartment provision, § 340-9I, meant to let related parties of different generations live together, so long as the arrangement is not outweighed by an adverse impact on the community.
Can you build an ADU in Webster, NY?
All districts prohibit ADUs.
The village has no accessory apartment. In R-2-9.6 and RM the Zoning Board of Appeals may authorise altering a single-family dwelling for double-house use if the house was standing on 11-8-1976, which creates two full dwellings.
ADU questions people ask about Monroe County
Are ADUs allowed in Monroe County?
There is no single county-wide answer — ADUs are governed by each town, city and village, not by the county. Of the 30 Monroe County municipalities with mapped zoning districts, 18 allow an accessory dwelling unit in at least one district, and 1 allow one by right somewhere. The section for your municipality below gives the specific answer.
Does Monroe 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 Monroe 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 Monroe County
Permission and budget are separate questions. See the Monroe 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 Monroe County: Zoning for new construction by town · Cost to build · ADU rules across every county we cover
ADU information for Monroe County is compiled from each municipality's own code , most recently reviewed 2026-10-11, 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. Source: the Offsite / Aldo zoning dataset.