ADU · Monroe County

Can you build an ADU in Webster, NY?

Village of Webster has 4 districts. All districts prohibit ADUs. Check your address to confirm the district that applies to your parcel:

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What the Webster code says

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.

Conditions the code attaches:

Under § 175-61 the conversion route reaches only single-family dwellings standing when the chapter was adopted on 11-8-1976, and it expressly excludes R-1-13.6 and R-1-9.6.
After the alteration the lot must have at least 5,000 square feet for each dwelling unit.
No unit may have less than 600 square feet of floor area used for living.
No living quarters in a basement, or in space with less than six feet of ceiling clearance above average outside ground level.
No exterior alteration is allowed except for safety and improved access.
The code sets no owner-occupancy or kinship condition. The building department can confirm details at (585) 265-3770.

What the Webster code indicates by district

The table below shows how each district treats ADUs, alongside the lot and setback standards that govern a second unit. District boundaries and conditions vary, so treat this 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-1-13.6 District	0.31 ac	40 / 8 / 40 ft	30 ft	No
Residential R-1-9.6 District	0.22 ac	40 / 6 / 40 ft	30 ft	No
Residential R-2-9.6 District	0.22 ac	40 / 6 / 40 ft	30 ft	No
Residential RM District	0.22 ac	40 / 6 / 40 ft	35 ft	No

Residential R-1-13.6 District - Under § 175-11A(2), 50% in number of the lots on any subdivision plan must be at least 16,000 sq ft, so the minimum shown is the floor for an individual lot, not an achievable average across a plan.

Where principal structures front the same street within 300 ft of either side line, the front yard is the average of the nearest setbacks on each side, never less than 20 ft.
With a principal structure on one side only, the front yard is the average of that setback and 40 ft, again never less than 20 ft.
On a lot under 70 ft wide held in separate ownership when the chapter took effect, the 20 ft side yard total drops one foot per foot under 70, to no less than 12 ft.
Once that reduced side yard total is below 16 ft, the two side yards must be equal.
The 30 ft height limit is for dwellings and structures attached to them. Detached garages are limited to 18 ft and accessory buildings to 10 ft.
Lot coverage counts all buildings, accessory buildings included.

Residential R-1-9.6 District - The front yard is contextual: where principal structures front the same street within 300 ft of either side line, the depth is the average of the nearest setbacks on each side, never under 20 ft. With a structure on one side only, it is the average of that setback and 40 ft.

On a lot under 60 ft wide held in separate ownership when the chapter took effect, the 16 ft side yard total drops six inches per foot under 60, to no less than 10 ft.
Once that reduced side yard total is below 12 ft, the two side yards must be equal.
The 30 ft height limit is for dwellings and structures attached to them. Detached garages are limited to 18 ft and accessory buildings to 10 ft.
Lot coverage counts all buildings, accessory buildings included.

Residential R-2-9.6 District - The figures shown are for a single-family dwelling. The front yard is contextual: where principal structures front the same street within 300 ft of either side line, the required depth is the average of the nearest setbacks on each side, never less than 20 ft.

A two-family dwelling is a controlled site use needing site plan approval: 18,000 sq ft on 100 ft of width, with the two side yards totalling 26 ft and neither under 10 ft.
Townhouses are sized by density: 2,000 sq ft per dwelling unit, a minimum of 1 acre for each group, and a hard cap of 8 units per acre, which is what binds.
With a principal structure on one side only, the front yard is the average of that setback and 40 ft.
On a lot under 60 ft wide in separate ownership when the chapter took effect, the 16 ft side yard total drops six inches per foot under 60, to no less than 10 ft, and splits equally below 12 ft.
The 30 ft height limit is for dwellings and attached structures; detached garages are limited to 18 ft and accessory buildings to 10 ft, and lot coverage counts all buildings.

Residential RM District - The figures shown are for a single-family dwelling, and the 35 ft height covers single-family, two-family and townhouse buildings only. Two-family, townhouse, multiple-family and condominium development all require site plan review under Article XIV.

A two-family dwelling is a controlled site use needing site plan approval: 18,000 sq ft on 100 ft of width, with the two side yards totalling 26 ft and neither under 10 ft.
Townhouses are sized by density: 2,000 sq ft per dwelling unit, a minimum of 1 acre for each group, a hard cap of 8 units per acre, and a 40 ft side yard.
A multiple-family dwelling needs 20,000 sq ft for the first 2 units plus 3,000 sq ft for each beyond, on 150 ft of width, and stands twice its height from a side or rear line, 80 ft at 40 ft.
Where structures front the same street within 300 ft of either side line, the front yard is the average of the nearest setbacks, never under 20 ft; with one side only, the average of it and 40 ft.
On a lot under 60 ft wide in separate ownership when the chapter took effect, the 16 ft side yard total drops six inches per foot under 60, to no less than 10 ft, and splits equally below 12 ft.
Lot coverage counts all buildings, accessory buildings included.

ADUs vs. short-term rentals in Webster

Short-term rentals prohibited for Village of Webster. Each residential district in the Village of Webster permits only the uses on its list, and no list includes a tourist home, bed-and-breakfast, rooming or boarding house, or hotel or motel. A use absent from the list is barred. These are separate questions from whether you can build an ADU — a unit you're allowed to add isn't automatically one you're allowed to rent nightly, so check both.

Good to know

Residential lot minimum0.22–0.31 ac — an ADU still has to fit the district's lot and setback envelope.
UtilityRG&E territory.
Zoning codeecode360.com/7738156
Building dept(585) 265-3770

ADU FAQ — Webster, NY

Are ADUs allowed in Webster, NY?

Village of Webster has 4 districts. All districts prohibit ADUs. Check your address with the free ADU checker, or confirm with the building department at (585) 265-3770.

Do I need a special permit for an ADU in Webster?

No. No district in Village of Webster permits an ADU, so there is no permit to apply for. Codes change, so verify with the building department at (585) 265-3770 before ruling it out.

Can I use an ADU as a short-term rental in Webster?

Short-term rentals prohibited for Village of Webster. ADU occupancy and short-term-rental rules are separate: an ADU you can build isn't automatically one you can rent nightly. Confirm both before you count on STR income.

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What an ADU costs to build in Webster

Permission is one question and budget is another. An 800 sq ft accessory unit here runs roughly $200k–260k at a standard finish, and the per-square-foot rate comes in above a full house because the kitchen, bath, panel and heating plant cost the same either way. See the full cost to build an ADU in Webster, priced by size.

How we know this

Sections analyzed: Ch. 175 § 175-61 alteration of existing dwellings; §§ 175-10, 175-12, 175-14, 175-16, 175-42, 175-59, 175-3
Districts confirmed: 4 of 4 — every mapped district.
Last reviewed: 2026-08-14
Not covered here: Overlay districts, the zoning map, and any conditions attached to an individual parcel. Size limits and owner-occupancy terms sit in the code section above, not in this summary.

More on Webster: Full zoning for new construction · ADU build cost · House build cost · ADU rules across Monroe County · All Monroe County towns

ADU information for Village of Webster is compiled from the municipal code (last reviewed 2026-08-14) and provided for decision-support only — not legal or architectural advice. ADU eligibility, size, owner-occupancy and permit conditions vary by district and often carry exceptions; verify with the building department at (585) 265-3770 before relying on any answer. Source: the Offsite / Aldo zoning dataset.