What this is
The Stay Cottage is a concept. It is an original idea we drew for one of the most common reasons people build an ADU: a parent moving in close by. It is not a finished build and it is not an approved plan. A real version starts with your lot, your town’s rules and drawings from a licensed designer.
Everything is on one floor. You come in from a small covered porch without a step, the living room and kitchen open to each other, and the bedroom, bathroom and laundry sit together at the back.
Who it suits
It is built for an aging parent, and it works just as well for you if you plan to downsize and stay on your own land someday. Interest is real: in AARP’s 2021 survey, 62% of adults 50 and older said they would consider building an ADU for a loved one (AARP, 2021).
Plans change, though. A cottage built for a parent can later house a caregiver or a tenant, if your town allows it. One-level, step-free design suits all of those people.
How it lives
The design borrows its measurements from the federal accessibility standards for public buildings. Those standards don’t govern a private ADU, but they are a well-tested yardstick (US Department of Justice, 2010 ADA Standards):
- No ramp. A ramp can climb no more than 1 inch for every 12 inches of length (ADA Standards, sec. 405.2), so a 24-inch rise needs about 24 feet of ramp. Setting the floor close to the ground avoids it.
- Wide doors. Doors should leave at least 32 inches of clear opening (ADA Standards, sec. 404.2.3).
- Room to turn. The bath and bedroom each leave a 60-inch circle open for a wheelchair (ADA Standards, sec. 304.3).
- Grab bars later. Wood blocking goes in the bathroom walls during framing, at the height where bars belong, 33 to 36 inches up (ADA Standards, sec. 609.4).
A second door links the bedroom straight to the bathroom, so a night-time trip is short and private. The laundry closet is a few steps away, not down a flight of stairs. Our aging-in-place guide covers more of these choices.
What changes the cost
- Foundation. A floor near the ground often means a slab. An insulated shallow foundation can work for a building kept heated, with a monthly average indoor temperature of at least 64°F (2025 Residential Code of New York State, sec. R403.3).
- The shower. A curbless shower has to be planned into the floor framing and drainage before construction starts. Adding it later costs far more.
- Utilities and the path. Trench length to water, sewer or septic, and power adds up, and so does a paved, lit walkway a parent can use safely in winter.
What to check with your town
- Who may live there. Some towns limit an ADU to relatives. The Town of East Bloomfield allows its detached units only for family members, by special use permit (a permit a town board grants case by case, usually after a public hearing), and treats them as temporary (Town of East Bloomfield, sec. 135-83.4). That can suit a parent and rule out a future rental.
- Owner occupancy. Many towns require the owner to live on the property. The Town of Clarkson asks for a notarized affidavit (Town of Clarkson, sec. 140-23.4).
- Size caps. Caps vary a lot. Clarkson limits an ADU to 30% of the main home’s living area (Town of Clarkson, sec. 140-23.4), and the Village of Fairport caps it at 650 square feet (Village of Fairport, sec. 551-26).
- Detached or attached. Fairport prohibits detached ADUs (Village of Fairport, sec. 551-26). An attached unit needs walls and floors with a 1-hour fire rating between the two homes (2025 Residential Code of New York State, sec. R302.3).
Look up your area on the New York rules page, or start with the property checker.
What moves the price
- A foundation that keeps the floor close to the ground
- Curbless shower framing and drainage
- Distance to water, sewer or septic, and power
- A paved, lit path to the main house
What to check in each municipality
A first comparison with the codes we’ve read. A listed restriction identifies a conflict with this concept. Other results require local confirmation; missing research does not mean a ban or approval. Your zoning district, your lot and the municipality’s review still decide.
| Municipality | Screen | Size rule | Checked |
|---|---|---|---|
| Town of Clarkson | Below the 600 sq ft one-bedroom minimum | No more than 30% of the main home's living space (unit minimums 450 sq ft efficiency, 600 sq ft one-bedroom) | October 4, 2026 |
| Village of Fairport | Detached restriction: Detached ADUs are prohibited | 650 sq ft | October 4, 2026 |
| Town of Penfield | Detached units are excluded from the researched in-law route | No more than 30% of the total area of the residence | October 4, 2026 |
| Village of Pittsford | Only within this code’s size limits; check them | No square-foot cap; house-size and structure-size tests apply | October 4, 2026 |
| Town of Canandaigua | Requires local confirmation of the district, size rule and approvals | No separate cap; the district's bulk and area rules for a single-family home apply | October 3, 2026 |
| Town of East Bloomfield | Family members only, so it can’t be rented, and a detached unit must be removed when family stops using it. Only within this code’s size limits; check them | Detached: 500 to 850 sq ft gross floor area. In-law apartment: no size cap found | October 3, 2026 |
| Town of Perinton | Detached restriction: Living in accessory buildings is barred in the covered residential districts | Not applicable | September 16, 2026 |
| City of Rochester | Rule change under study; confirm the current route with the municipality | Conversion: building at least 1,500 sq ft and lot at least 6,000 sq ft, plus unit minimums | October 4, 2026 |