Hilton · ADU cost
What it costs to build an ADU in Hilton, NY
An 800 sq ft accessory dwelling unit in Hilton runs roughly $200k–260k, or about $249–327/sq ft, and that per-square-foot figure sits deliberately above the $204–268/sq ft a full house costs here. An ADU still needs one whole kitchen, one whole bath, its own service panel and its own heating plant no matter how small you draw it, and those costs do not shrink with the floor plan, so they land on half the square footage and push the rate up. Whether the village will let you build one is a separate question from what it costs, and it gets answered parcel by parcel rather than townwide, since the Village of Hilton maps 2 districts that treat accessory units differently from one another, so read the table below as a starting point rather than a verdict.
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ADU cost by size in Hilton
Standard finish, slab on grade, on a flat and clear part of the lot, general-contractor margin included. These are structure costs at Monroe County pricing, before the service and septic work a second dwelling can trigger.
| Size | Type | $ / sq ft | Estimated total |
|---|---|---|---|
| 400 sq ft | Studio | $331–$433 | $130k–175k |
| 600 sq ft | One bedroom | $276–$362 | $165k–215k |
| 800 sq ft | One bedroom, larger | $249–$327 | $200k–260k |
| 1,000 sq ft | Two bedroom | $233–$305 | $235k–305k |
400 sq ft — One room plus a bath. Garage conversions and small backyard cottages land here.
600 sq ft — The most common detached build - a real bedroom, full kitchen, one bath.
800 sq ft — Room for a proper living area. Still a single bath and one kitchen.
1,000 sq ft — About as large as most codes allow an accessory unit to go.
Why the rate is higher than a house
The systems below are priced for an 800 sq ft unit. The middle column is what each system would cost if it simply shrank with the floor plan; the left column is what it actually costs once you account for the equipment a dwelling needs one of regardless of size. The gap between the two columns is the whole reason small builds price the way they do.
| System | $ / sq ft in an ADU | If it scaled with floor area | Fixed per unit |
|---|---|---|---|
| Site work | $7–$11 | $7 | — |
| Foundation | $16–$23 | $16 | — |
| Framing | $25–$32 | $25 | — |
| Envelope - roof, siding, windows | $32–$41 | $32 | — |
| Plumbing | $28–$34 | $16 | 55% |
| Electrical | $18–$24 | $13 | 35% |
| HVAC | $23–$28 | $15 | 45% |
| Insulation | $7–$9 | $7 | — |
| Interior finishes | $32–$43 | $27 | 15% |
| Millwork & cabinetry | $18–$28 | $11 | 55% |
The fixed-per-unit share is a modeling assumption, not a figure from the code: it is our estimate of how much of each system's budget buys equipment a dwelling needs exactly one of - a kitchen rough-in, a bath group, a service panel, a heating plant - and therefore does not shrink when the unit does. Site work, foundation, framing, envelope and insulation are treated as scaling straight with floor area, which understates the premium slightly, because a small building carries more envelope per square foot of floor than a large one.
What the Hilton code says about accessory units
Whether you can build one, and how large, is decided by the district your parcel sits in rather than by the town as a whole. The table shows how each mapped district treats ADUs alongside the lot and setback standards a second unit still has to fit inside. District boundaries and conditions vary, so treat it as a starting point and confirm the district that applies to your parcel.
| District | Min lot | Setbacks F / S / R | Max height | ADU |
|---|---|---|---|---|
| Residential | 0.18 ac | 20 / 8 / 8 ft | 35 ft | Special permit |
| Multiple-Residence | 0.18 ac | 30 / 15 / 15 ft | 35 ft | No |
Residential - The front setback is the most common existing front setback on the block; the 20 ft figure applies only where that cannot be determined.
- Two-family, single-family attached, small apartment house, cottage court and live-work units need site approval under Article IV and meet the same lot, setbacks and coverage as a detached house.
- Coverage counts all buildings, including accessory structures.
- A shed needs 5 ft side and rear setbacks, a 16 ft height cap, a footprint over 25 and up to 256 sq ft and no wall longer than 20 ft, and only one is permitted per property.
- A detached garage needs 8 ft side and rear setbacks, a 25 ft height cap and a 720 sq ft footprint cap.
- Sheds and garages must stand behind the front main foundation line of the house, 10 ft from any residential building on an adjacent lot, and 30 ft from either street line on a through lot.
- No more than three single-family homes of substantially similar style may stand on three adjacent lots fronting the same street.
Multiple-Residence - MR is a floating district, zoned only on application for a specific proposal through rezoning, and the land reverts to its previous district if construction is not diligently prosecuted within two years of the local law designating it.
- The setbacks apply at the project perimeter: 30 ft from a major peripheral road right-of-way, and 15 ft from an exterior project road, measured from the paved area where it is not dedicated.
- Buildings must also stand 15 ft from any interior lot line other than one defining an individual townhouse unit.
- The 80% coverage is calculated on the total project area, and the 8,000 sq ft is a minimum site size.
- The district states no minimum lot width, no land requirement per dwelling unit and no cap on units, so yield is set by site plan approval under Article V.
- The Zoning Board of Appeals may extend the two-year deadline, but not past three years (§ 275-14H).
- Apartment houses, multiple dwellings, dwelling groups, condominiums, cooperatives, single-family attached and cottage court dwellings are permitted outright; a detached house needs a special permit.
Size limits on record in Hilton
Where the code states a size cap, it decides which row of the cost table above actually applies to you. These are the caps recorded for Hilton:
- ResidentialThe R district minimum lot is 8,000 sq ft.
- Multiple-ResidenceThe R district minimum lot is 8,000 sq ft.
Costs an ADU adds that a house does not
- Septic and water A second dwelling adds bedrooms to the design flow, which on an unsewered parcel often means expanding or replacing the existing system rather than tapping it. This is the single most common reason an ADU budget moves after design, and it is site-specific enough that no model should quote it - get it evaluated early.
- Utility service RG&E territory. A detached unit needs power run to it, and whether it goes on its own meter or subfeeds the main house changes both the cost and the permit path.
- Access and parking Many codes require an added parking space for the accessory unit, and a detached unit usually needs a driveway extension or a path, both of which count against a lot-coverage or impervious-surface cap.
- Short-term rentalsShort-term rentals allowed. Short-term rentals are a special permitted use in the R district, so each one needs site approval from the Village under Article IV. They are neither allowed by right nor banned. Separate question from whether you can build the unit.
- Zoning codeecode360.com/46615449
- Building dept(585) 392-4144
Sizing up a specific parcel in Hilton?
Aldo pulls the exact zoning district, setbacks, and build feasibility for any parcel — before you buy. Enter your email to open Aldo and run your free report.
Building a full house instead?
A standard-finish house in Hilton runs $204–268/sq ft, about $370k–480k at 1,800 sq ft . See what it costs to build a house in Hilton.
ADU cost in nearby towns
All Monroe County towns: Rochester (City) · Brighton · Chili · Clarkson · Gates · Greece · Hamlin · Henrietta · Irondequoit · Mendon · Ogden · Parma · Penfield · Perinton · Pittsford · Riga · Rush · Sweden · Webster · Wheatland · East Rochester (Village) · Brockport (Village) · Churchville (Village) · Fairport (Village) · Honeoye Falls (Village) · Pittsford (Village) · Scottsville (Village) · Spencerport (Village) · Webster (Village)
More on Hilton: Can you build an ADU here? · Zoning for new construction · Monroe County build cost
ADU cost in Hilton: common questions
How much does it cost to build an ADU in Hilton, NY?
An 800 sq ft accessory dwelling unit in Village of Hilton runs roughly $200k–260k at a standard finish, general-contractor margin included. A 400 sq ft studio runs about $130k–175k. Those are structure costs on an easy site and do not include the septic, water or electrical service work a second unit often triggers.
Why does an ADU cost more per square foot than a house in Hilton?
Because a lot of a dwelling's cost is per dwelling, not per square foot. One kitchen, one bath group, one service panel and one heating plant cost about the same in an 800 sq ft cottage as in a 1,800 sq ft house, so on the smaller unit they get spread over less than half the floor area. That is why an ADU here prices at $249–327/sq ft against $204–268/sq ft for a full house, even though it is the same trades doing the same work.
Are ADUs allowed in Hilton?
Village of Hilton has 2 districts. 1 district prohibits ADUs, 1 requires a special-use permit. Check the specific address with the free ADU checker or confirm with the building department at (585) 392-4144 before you spend money on design.
Can I rent an ADU in Hilton short term?
Short-term rentals allowed for Village of Hilton. ADU rules and short-term-rental rules are set separately, so a unit you are allowed to build is not automatically one you are allowed to rent nightly. Confirm both before you underwrite the build on short-term-rental income.
ADU costs are modeled estimates in current 2026 dollars at the Monroe County regional index, general-contractor margin included, derived from Offsite's cost engine with a stated adjustment for the equipment a dwelling needs one of regardless of size. They are planning numbers for decision-support only - not a bid, quote, or guarantee, and not legal, architectural or engineering advice. They cover the structure and exclude septic expansion, utility service runs, site work beyond a flat and clear pad, and permit fees. ADU eligibility, size, owner-occupancy and permit conditions in the Village of Hilton vary by district and often carry exceptions this page does not show; zoning last reviewed 2026-08-13; verify with the building department at (585) 392-4144 before relying on any answer. Sources: the Offsite / Aldo cost engine and zoning dataset.