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.
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 (R) — 8,000 sf (0.18 acres) with 60 ft of lot width, side setback 8 ft, rear setback 8 ft, maximum dwelling height 35 ft and a MAXIMUM BUILDING LOT COVERAGE OF 70%, by a wide margin the highest residential coverage allowance recorded in Monroe County. THE FRONT SETBACK IS CONTEXTUAL, NOT FIXED, AND THE RECORDED 20 FT IS A FALLBACK RATHER THAN A STANDARD. Schedule 2 footnote 7 provides that 'the minimum front setback for lots abutting roads shall be THE MOST COMMON EXISTING FRONT SETBACK ON THE BLOCK', and only 'in the event that the most common front setback does not exist or cannot be determined' does the 20 ft figure apply. On any built-up Hilton street the neighbours set the building line, not the schedule, so 20 ft is the floor for a greenfield or indeterminate case and must not be quoted as the requirement without walking the block. ACCESSORY BUILDINGS ARE REGULATED SEPARATELY AND BY TYPE, which is unusual: a shed takes 5 ft side and rear setbacks, a 16 ft height cap and a 256 sf footprint cap, while a garage takes 8 ft side and rear, a 25 ft height cap and a 720 sf footprint cap. Both must be erected BEHIND the front main foundation line of the principal dwelling (footnote 1), which is why the accessory front setback reads 'not specified'. THE 70% COVERAGE FIGURE IS A BUILDING-LOT-COVERAGE FIGURE, and combined with the 256 sf and 720 sf accessory footprint caps it means the constraint on a Hilton lot is the setback envelope and the accessory caps rather than the percentage. THE USE LIST IS THE MOST PERMISSIVE IN THE COUNTY — see `aduNotes`: by special permit under Article IV the R District admits a two-family dwelling, single-family attached, a small apartment house, cottage court dwellings, live-work units, an accessory dwelling unit and short-term rentals, none of which appear together in any other Monroe jurisdiction. | 0.1837 ac | 20 / 8 / 8 ft | 35 ft | Special permit |
| Multiple-Residence (MR) — 8,000 sf minimum lot with NO MINIMUM LOT WIDTH STATED, a 35 ft height cap and an 80% maximum building lot coverage, the highest in the village. Apartment houses, multiple dwellings, dwelling groups, condominiums and cooperatives are permitted OUTRIGHT here, unlike the R District where every multi-unit form needs a special permit. MR IS A FLOATING DISTRICT RATHER THAN A MAPPED ONE, AND THAT IS THE MOST IMPORTANT FACT ABOUT IT: § 275-14A states that 'an area shall be zoned as an MR District ONLY UPON APPLICATION FOR A SPECIFIC PROPOSAL in accordance with the normal rezoning procedures'. So MR does not sit on the zoning map waiting to be used — a developer must apply to have land rezoned into it, scheme in hand, and the Village Board weighs the proposal against the chapter's general criteria and the current Comprehensive Plan. The stated purpose is explicit that the Village does not want multiple-family development at a scale where 'large areas of the Village become so devoted to such use that single-family residences would appear out of place', which is a policy brake on top of the rezoning discretion. Treat MR capacity as an outcome of a political process, not as an entitlement attaching to any parcel. THE SETBACKS ARE NOT IN THE SCHEDULE'S NORMAL COLUMNS — the row reads 'see notes section' and footnote 2 supplies them in project terms rather than lot terms: no building nearer than 30 FT to the right-of-way of any MAJOR ROAD PERIPHERAL TO THE SITE, no building nearer than 15 FT to the right-of-way of any EXTERIOR PROJECT ROAD (measured from the limits of the paved area where the street is not dedicated), and no building nearer than 15 FT to any INTERIOR LOT LINE other than lot lines defining an individual townhouse unit. The recorded front 30, side 15 and rear 15 map those project-perimeter figures onto the conventional fields; they are not per-lot setbacks in the ordinary sense and a townhouse party-wall line is expressly exempt. | 0.1837 ac | 30 / 15 / 15 ft | 35 ft | No |
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:
- Residential (R) — 8,000 sf (0.18 acres) with 60 ft of lot width, side setback 8 ft, rear setback 8 ft, maximum dwelling height 35 ft and a MAXIMUM BUILDING LOT COVERAGE OF 70%, by a wide margin the highest residential coverage allowance recorded in Monroe County. THE FRONT SETBACK IS CONTEXTUAL, NOT FIXED, AND THE RECORDED 20 FT IS A FALLBACK RATHER THAN A STANDARD. Schedule 2 footnote 7 provides that 'the minimum front setback for lots abutting roads shall be THE MOST COMMON EXISTING FRONT SETBACK ON THE BLOCK', and only 'in the event that the most common front setback does not exist or cannot be determined' does the 20 ft figure apply. On any built-up Hilton street the neighbours set the building line, not the schedule, so 20 ft is the floor for a greenfield or indeterminate case and must not be quoted as the requirement without walking the block. ACCESSORY BUILDINGS ARE REGULATED SEPARATELY AND BY TYPE, which is unusual: a shed takes 5 ft side and rear setbacks, a 16 ft height cap and a 256 sf footprint cap, while a garage takes 8 ft side and rear, a 25 ft height cap and a 720 sf footprint cap. Both must be erected BEHIND the front main foundation line of the principal dwelling (footnote 1), which is why the accessory front setback reads 'not specified'. THE 70% COVERAGE FIGURE IS A BUILDING-LOT-COVERAGE FIGURE, and combined with the 256 sf and 720 sf accessory footprint caps it means the constraint on a Hilton lot is the setback envelope and the accessory caps rather than the percentage. THE USE LIST IS THE MOST PERMISSIVE IN THE COUNTY — see `aduNotes`: by special permit under Article IV the R District admits a two-family dwelling, single-family attached, a small apartment house, cottage court dwellings, live-work units, an accessory dwelling unit and short-term rentals, none of which appear together in any other Monroe jurisdiction.So the R District, on an 8,000 sq ft minimum lot, contemplates by special permit almost the full missing-middle vocabulary
- Multiple-Residence (MR) — 8,000 sf minimum lot with NO MINIMUM LOT WIDTH STATED, a 35 ft height cap and an 80% maximum building lot coverage, the highest in the village. Apartment houses, multiple dwellings, dwelling groups, condominiums and cooperatives are permitted OUTRIGHT here, unlike the R District where every multi-unit form needs a special permit. MR IS A FLOATING DISTRICT RATHER THAN A MAPPED ONE, AND THAT IS THE MOST IMPORTANT FACT ABOUT IT: § 275-14A states that 'an area shall be zoned as an MR District ONLY UPON APPLICATION FOR A SPECIFIC PROPOSAL in accordance with the normal rezoning procedures'. So MR does not sit on the zoning map waiting to be used — a developer must apply to have land rezoned into it, scheme in hand, and the Village Board weighs the proposal against the chapter's general criteria and the current Comprehensive Plan. The stated purpose is explicit that the Village does not want multiple-family development at a scale where 'large areas of the Village become so devoted to such use that single-family residences would appear out of place', which is a policy brake on top of the rezoning discretion. Treat MR capacity as an outcome of a political process, not as an entitlement attaching to any parcel. THE SETBACKS ARE NOT IN THE SCHEDULE'S NORMAL COLUMNS — the row reads 'see notes section' and footnote 2 supplies them in project terms rather than lot terms: no building nearer than 30 FT to the right-of-way of any MAJOR ROAD PERIPHERAL TO THE SITE, no building nearer than 15 FT to the right-of-way of any EXTERIOR PROJECT ROAD (measured from the limits of the paved area where the street is not dedicated), and no building nearer than 15 FT to any INTERIOR LOT LINE other than lot lines defining an individual townhouse unit. The recorded front 30, side 15 and rear 15 map those project-perimeter figures onto the conventional fields; they are not per-lot setbacks in the ordinary sense and a townhouse party-wall line is expressly exempt.So the R District, on an 8,000 sq ft minimum lot, contemplates by special permit almost the full missing-middle vocabulary
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. HILTON EXPRESSLY PERMITS SHORT-TERM RENTALS AS A NAMED LAND USE, WHICH MAKES IT ONLY THE SECOND MONROE JURISDICTION AFTER MENDON WITH A POSITIVE STR REGIME AND THE FIRST TO PUT IT IN THE ZONING USE LIST RATHER THAN A SEPARATE CHAPTER. § 275-13B(15) lists 'Short-term rentals' as a SPECIAL PERMITTED USE in the Residential (R) District, available 'upon site approval and in accordance with Article IV'. This is a permission, not a prohibition — but it is a discretionary one: an STR in Hilton requires site approval from the Village, so it is neither by-right nor banned. Note the sharp contrast with the Town of Parma, which SURROUNDS this village: Parma's code has no STR provision at all. NEVER CARRY A TOWN FINDING TO ITS VILLAGE OR THE REVERSE — the same split already bit Pittsford (village has an STR law, town has none) and Rockland's Haverstraw. THE ARTICLE IV SITE-APPROVAL STANDARDS ARE WHAT GOVERN AN STR HERE. Pull Article IV before advising anyone that an STR is achievable on a specific Hilton parcel. A separate sweep of all 40 chapters of the Village Code found no standalone rental-licensing chapter of the Gates Ch. 148 or Mendon Ch. 208 kind, so § 275-13B(15) plus Article IV appears to be the whole regime. New York State's 2025 statewide short-term rental registry (Ch. 99 of the Laws of 2025) obliges every host to register regardless of local law. Confirm with Code Enforcement at (585) 392-4144. Separate question from whether you can build the unit.
- 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 · Town/Village of 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: Offsite / Aldo cost engine (costEngine.js + constants.js); zoning dataset (municipalData.js).