New York · Ontario County
ADU rules in Ontario County, town by town
New York has no statewide ADU law, so each town, village and city writes its own rules. We’ve checked 26 municipal codes in Ontario County so far. 13 of them describe a current way to approve an ADU or accessory apartment.
A village has its own zoning, separate from the town around it, and a ZIP code can cover both. Check which government is on your property tax bill. This table is a screening guide, not a permit answer: your zoning district and your lot decide. Codes change, so confirm with the code office before you spend money.
| Municipality | What the code says | Detached unit? | Size limit | Owner on site? | Checked |
|---|---|---|---|---|---|
| Village of Bloomfield | Shared-kitchen apartment only | Not addressed | No more than 50% of the main unit and no more than 750 sq ft | Code doesn’t say | October 3, 2026 |
| Town of Bristol | Allowed with a special use permit | Yes. The definition covers a unit detached from or inside a single-family home | At least 360 sq ft; no more than 900 sq ft or 40% of the main home's gross floor area,… | Yes. The owner's primary home is one of the two units, and the owner owns both | October 3, 2026 |
| Town of Canadice | Allowed with a special use permit (family only) | No. The apartment must be inside the house, sharing at least 25% of a wall | 300 to 800 sq ft, and no more than 35% of the house | Yes | October 3, 2026 |
| City of Canandaigua | No ADU rules yet | Not addressed | Code doesn’t say | Code doesn’t say | October 3, 2026 |
| Town of Canandaigua | Allowed with a permit | Yes, at least 10 ft from the house and meeting the setbacks and height for a home in… | No separate cap; the district's bulk and area rules for a single-family home apply | Yes. The owners of record live in either unit | October 3, 2026 |
| Village of Clifton Springs | No ADU rules yet Not confirmed yet | Not addressed | Code doesn’t say | Code doesn’t say | October 3, 2026 |
| Town of East Bloomfield | Allowed with a special use permit (family only) | Yes, in a detached accessory building (carriage house, garage or similar) under §135-83.4 | Detached: 500 to 850 sq ft gross floor area. In-law apartment: no size cap found | Yes. An owner of record lives in one of the units | October 3, 2026 |
| Town of Farmington | No ADU rules yet Not confirmed yet | Not addressed | Code doesn’t say | Code doesn’t say | October 3, 2026 |
| City of Geneva | Allowed with a special use permit | Yes, in a detached garage or other accessory structure in the rear yard with at least… | No square-foot cap found beyond the house-size and accessory-structure tests | Yes. Owner lives in one unit as primary home and signs a notarized affidavit; a new… | October 3, 2026 |
| Town of Geneva | No ADU rules yet Not confirmed yet | Not addressed | Code doesn’t say | Code doesn’t say | October 3, 2026 |
| Town of Gorham | Allowed with a special use permit | No. The apartment must be inside the house, sharing at least 25% of a wall | 300 to 800 sq ft, and no more than 35% of the house | Yes | October 3, 2026 |
| Town of Hopewell | No ADU rules yet Not confirmed yet | Not addressed | Code doesn’t say | Code doesn’t say | October 3, 2026 |
| Town of Manchester | No ADU rules yet Not confirmed yet | Not addressed | Code doesn’t say | Code doesn’t say | October 3, 2026 |
| Village of Manchester | No ADU rules yet Not confirmed yet | No. Not allowed in R-1: one principal structure per lot (§290-34A) | Code doesn’t say | Code doesn’t say | October 3, 2026 |
| Town of Naples | No ADU rules yet Not confirmed yet | Likely not: one principal building per lot (§132-16B) | Code doesn’t say | Code doesn’t say | October 3, 2026 |
| Village of Naples | Allowed with a special use permit | Not determined | Code doesn’t say | Code doesn’t say | October 3, 2026 |
| Town of Phelps | Allowed with a special use permit | Conversion of an existing detached accessory building only; new detached construction… | Up to 720 sq ft gross floor area (units of 400 sq ft or less follow Appendix Q of the… | Yes. One unit is the principal residence of an owner (rules also cover LLCs and trusts) | October 3, 2026 |
| Village of Phelps | Allowed with a special use permit | Yes, a new detached unit or a converted existing accessory building | Up to 720 sq ft gross floor area (400 sq ft or less follows Appendix Q) | Yes. One unit is an owner's principal residence; proof may be required at renewal | October 3, 2026 |
| Town of Richmond | No ADU rules yet Not confirmed yet | Not addressed | Code doesn’t say | Code doesn’t say | October 3, 2026 |
| Village of Rushville | Allowed; permit type not confirmed | Code doesn’t say | In-house units: house of at least 1,450 sq ft before alteration (§5.2F) | The owner must live in one of the two units (§5.2B) | October 13, 2026 |
| Town of Seneca | Limited apartment allowed | Not determined | Code doesn’t say | Code doesn’t say | October 3, 2026 |
| Village of Shortsville | No ADU rules yet Not confirmed yet | Not addressed | Code doesn’t say | Code doesn’t say | October 3, 2026 |
| Town of South Bristol | No ADU rules yet Not confirmed yet | Only by special use permit for a second principal use (§170-14C) | Code doesn’t say | Code doesn’t say | October 3, 2026 |
| Town of Victor | No ADU rules yet | Not addressed | Code doesn’t say | Code doesn’t say | October 3, 2026 |
| Village of Victor | No ADU rules yet Not confirmed yet | Not addressed | Code doesn’t say | Code doesn’t say | October 3, 2026 |
| Town of West Bloomfield | Limited apartment allowed | Likely not: one principal building per lot in AG, R-1, R-2 (§140-118A) | Code doesn’t say | Code doesn’t say | October 13, 2026 |
Dates link to the code we read. “No ADU rules yet” means we found no ADU rules in the code. That isn’t permission, and some codes allow only one home or one main building on a lot: here’s what to do.
Room for what comes next
Planning an ADU in Ontario County?
Understand the rules, compare your options and make a list of questions for your municipality.