Evans · ADU cost
What it costs to build an ADU in Evans, NY
An 800 sq ft accessory dwelling unit in Evans 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 town 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 Town of Evans maps 17 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 Evans
Standard finish, slab on grade, on a flat and clear part of the lot, general-contractor margin included. These are structure costs at Erie 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 Evans 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 |
|---|---|---|---|---|
| Rural Residential District | 1 ac | 50 / 30 / 50 ft | 30 ft | Special permit |
| Residential District One | 0.46 ac | 40 / 8 / 35 ft | 30 ft | Special permit |
| Residential District One-Lakefront | 0.92 ac | 50 / 20 / 50 ft | 35 ft | Special permit |
| Residential District Two | 0.23 ac | 25 / 5 / 30 ft | 30 ft | Special permit |
| Agriculture and Open Space District | 5 ac | 60 / 35 / 50 ft | 35 ft | Special permit |
| Rural Agriculture District | 3 ac | 60 / 35 / 50 ft | 35 ft | Special permit |
| Multifamily Residential District Three | 0.23 ac | 25 / 5 / 30 ft | 30 ft | Special permit |
| Multifamily Residential District Four | 0.23 ac | 25 / 5 / 30 ft | 30 ft | Special permit |
| Mobile Home Residential District Five | 0.11 ac | 30 / 8 / 10 ft | — | No |
| Public Facilities District | — | 50 / 15 / 15 ft | 35 ft | No |
| Recreational Facilities District | — | 50 / 15 / 15 ft | 35 ft | No |
| Neighborhood Business District | 0.5 ac | 40 / 0 / 15 ft | 30 ft | No |
| General Business District | — | 30 / 0 / 15 ft | 50 ft | No |
| Motor Vehicle Service District | 1 ac | 60 / 25 / 25 ft | 35 ft | No |
| Waterfront Mixed Use District | — | 15 / 0 / 15 ft | 40 ft | — |
| Light Industrial District | 1 ac | 40 / 15 / 15 ft | 30 ft | No |
| General Industrial District | 1 ac | 40 / 15 / 15 ft | 30 ft | No |
Residential District One - The lot minimum shown is the unsewered case, which the code calls the minimum Health Department requirement. On public sewer the lot falls to at least 12,150 sq ft, or 13,500 sq ft on a corner.
- The two side yards must add to at least 20 ft and neither may be under 8 ft, so 8 ft on both sides fails the combined test
- The lot must be at least 125 ft wide without public sewer, and at least 90 ft on an interior lot or 100 ft on a corner with it
Residential District One-Lakefront - The lot minimum shown is the unsewered case. With public sewer the lot falls to at least 30,000 sq ft, or 35,000 sq ft on a corner.
- The lot must be at least 200 ft wide without public sewer, and at least 150 ft on an interior lot or 175 ft on a corner with it
- The 20 ft side yard is a flat figure for each side here, not a combined total
Residential District Two - A two-family dwelling needs a lot of at least 15,000 sq ft on 120 ft of width, 130 ft on a corner. The two side yards must add to at least 15 ft, and neither may be under 5 ft, so building to 5 ft on both sides fails the combined test.
- Inside the Lake Erie Beach neighborhood, as the zoning map defines it, a one-family lot needs only 6,000 sq ft, interior or corner, on 60 ft of width
- In that neighborhood a one-storey house needs a 900 sq ft first floor rather than 1,100 sq ft
- The lot figures shown are for a one-family dwelling outside the Lake Erie Beach neighborhood, where a corner lot needs 11,250 sq ft on 90 ft of width
Agriculture and Open Space District - The height limit depends on what the building is: 35 ft for an ordinary structure, 50 ft for an agricultural building and one hundred feet for a silo.
- A house needs at least 1,200 sq ft of livable floor area under two storeys and 1,600 sq ft at two, excluding attic, basement, cellar and attached garage
- A campground needs at least ten acres and may put no structure, campsite or use within 300 ft of a residential property line
- Keeping horses, mules or donkeys takes at least two acres for the first two animals and more for each after
- Up to six working dogs may be kept on a property of at least five acres
Rural Agriculture District - The height limit depends on what the building is: 35 ft for an ordinary structure, 50 ft for an agricultural building and one hundred feet for a silo.
- A house needs at least 1,200 sq ft of livable floor area under two storeys and 1,600 sq ft at two, excluding attic, basement, cellar and attached garage
- A campground needs at least ten acres and may put no structure, campsite or use within 300 ft of a residential property line
- Keeping horses, mules or donkeys takes at least two acres for the first two animals and more for each after
Multifamily Residential District Three - The figures shown are for a detached house on its own lot. Attached units are governed instead by density: at least 4,300 sq ft of gross land for each dwelling unit, excluding perimeter public streets, on a 120 ft width.
- Attached units take a 30 ft front yard, 40 ft side and rear yards, 35% coverage and 35 ft of height
- A detached unit not on an individual lot takes at least 7,500 sq ft of gross land instead, with side yards settled by the arrangement of buildings, drives and open space
- An attached dwelling runs from at least 400 sq ft for a studio to 640 for one bedroom, 760 for two and 1,000 for three, with a further 180 for each bedroom beyond
- No main or longitudinal wall in a row of units may run more than 132 ft without a 90-degree offset of at least 10 ft, and no elevation may exceed 176 ft
- Principal structures must stand 30 ft apart
Multifamily Residential District Four - The figures shown are for a detached house on its own lot. Attached units are governed instead by density: at least 3,000 sq ft of land for each dwelling unit, on a 150 ft width with 40% coverage and 35 ft of height.
- Attached units carry no yard figure at all: § 200-14D settles front, side and rear yards by a spacing formula driven by building height and arrangement
- An accessory structure stops at 16 ft, and counted with the principal building it raises the coverage cap to 45%
- Minimum dwelling size runs from 400 sq ft for a studio to 1,000 for three bedrooms, with 180 added per bedroom beyond
- No wall in a row of units may run more than 132 ft without a 90-degree offset of at least 10 ft, and no elevation may exceed 176 ft
- A dormitory, fraternity or sorority house needs a special permit from the Town Board
Mobile Home Residential District Five - Two standards run at once: the figures shown are for one lot inside the development, and the development itself must be at least 8.26 acres exclusive of road rights-of-way and hold between 50 and 350 sites.
- On top of the lot, a further 2,400 sq ft per lot must be set aside as common open space, and neither the lot area nor the paved access road counts towards it
- The two side yards must add to at least 14 ft, split eight feet on one side and six on the other
- No mobile home may stand within 50 ft of the development boundary, within 14 ft of another including its accessory structures, or within 300 ft of a public road
- No mobile home may front a public street: all frontage is on private access roads screened from public view
- Livable floor space is at least 700 sq ft for one or two occupants, plus 150 sq ft for each occupant beyond two
- The 40 ft width may be halved at the setback line on a pie-shaped cul-de-sac lot
Public Facilities District - The side and rear yards shown apply against another non-residential lot. Where the lot abuts a residential district they rise to 25 ft at the side and 50 ft at the rear.
- No lot area is set: the parcel must simply be large enough for the buildings, parking, loading, landscaping, yards and open spaces, and coverage is settled the same way
- Parking, loading and stacking areas stand 15 ft back from the street, 25 ft from a residential district and 10 ft otherwise, and the whole of that setback area must be landscaped
Recreational Facilities District - The side and rear yards shown apply against another non-residential lot. Where the lot abuts a residential district they rise to 25 ft at the side and 50 ft at the rear.
- No lot area is set: the parcel must simply be large enough for the buildings, parking, loading, landscaping, yards and open spaces, and coverage is settled the same way
- Parking, loading and stacking areas stand 15 ft back from the street, 25 ft from a residential district and 10 ft otherwise, and the whole of that setback area must be landscaped
- An outdoor recreation activity may not sit within 150 ft of an abutting residential district unless the land is Town-owned
Neighborhood Business District - No side yard is required against another non-residential lot, though a separated building must keep at least ten feet. Against a residential district the side and rear yards both become 25 ft.
- Lot coverage is settled by the yard, parking and landscaping requirements rather than by a percentage
- Where half a block is already built, the front yard becomes the average of the existing buildings on either side
- On a corner lot the shorter street line is the front, and the side yard facing the other street must be at least as deep as the front yard
- The whole of any parking, loading and stacking setback must be landscaped
General Business District - The district states no minimum lot area, with one exception that is unusually severe: a self-storage facility needs at least four acres.
- A self-storage facility takes a three hundred foot front setback, 25 ft side and rear yards against another non-residential lot and 50 ft against a residential district
- It must stand one hundred feet from a residential structure, is capped at 35 ft where everything else here may reach 50, and must hold at least 10,000 sq ft of interior storage space
- No side yard is required against another non-residential lot, though a separated building must keep at least ten feet; against a residential district the side and rear yards both become 25 ft
- Buildings on the same site must stand 30 ft apart
- Where half a block is already built, the front yard becomes the average of the existing buildings on either side
- Lot coverage is settled by the yard, parking and landscaping requirements rather than by a percentage
Motor Vehicle Service District - The 25 ft side and rear yards apply against another non-residential lot. Against a residential district both rise to fifty.
- Buildings on the same site must stand 30 ft apart
- Parking, loading and stacking areas stand 20 ft back from the street, 25 ft from a residential district and 10 ft otherwise, and the whole of that area must be landscaped
- Lot coverage is settled by the yard, parking and landscaping requirements rather than by a percentage
Waterfront Mixed Use District - The front setback is a band, not a minimum: 15 to 30 ft from the street right-of-way, and on a waterfront lot 140 to 170 ft from the waterside lot line.
- Height has a floor as well as a ceiling: at least two usable storeys, with a 14 ft minimum ground floor for a commercial building
- The 40 ft limit is measured to the eave, and 50 ft is allowed only where that part of the building stands at least 150 ft back from a residential district
- No side yard is required between contiguous buildings; otherwise eight feet, rising to 25 ft where a commercial use abuts a residential district and 10 ft where a residential use does
- The rear yard is 15 ft, or 25 ft against a residential district
- Coverage is capped by floor area rather than by percentage, at 15,000 gross sq ft per storey, and ground-floor residential use is precluded entirely
- Drive-throughs, vehicle sales and service, filling stations, warehousing, laundromats and standalone parking lots are prohibited outright
Light Industrial District - The 30 ft height is the by-right ceiling: going taller needs a special use permit, and it brings much larger yards with it, a 75 ft front yard and 75 ft at the side and rear against a residential district.
- The side and rear yards shown are for a building under 30 ft abutting another non-residential lot; against a residential district they are 50 ft
- All manufacturing and processing must be completely enclosed in buildings
- Outdoor storage is barred from any front yard, must be screened, may not exceed 16 ft in height and may come no closer than 50 ft to a property line
- Buildings on the same site must stand 30 ft apart
- Lot coverage is settled by the yard, parking and landscaping requirements rather than by a percentage
- Rooftop mechanical space may rise above the height limit if it is set back 15 ft from any exterior wall, held under 15 ft and screened
General Industrial District - The 30 ft height is the by-right ceiling: going taller needs a special use permit, and it brings much larger yards with it, a 75 ft front yard and 75 ft at the side and rear against a residential district.
- The side and rear yards shown are for a building under 30 ft abutting another non-residential lot; against a residential district they are 50 ft
- Manufacturing here need not be enclosed, and adult uses are confined to this district
- Outdoor storage is barred from any front yard, must be screened, may not exceed 16 ft in height and may come no closer than 50 ft to a property line
- Buildings on the same site must stand 30 ft apart
- Lot coverage is settled by the yard, parking and landscaping requirements rather than by a percentage
- Rooftop mechanical space may rise above the height limit if it is set back 15 ft from any exterior wall, held under 15 ft and screened
Size limits on record in Evans
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 Evans:
- Rural Residential DistrictThe unit must be carved out of the space within the house, not built as a separate building, and may not exceed 500 sq ft of that space
- Residential District OneThe unit must be carved out of the space within the house, not built as a separate building, and may not exceed 500 sq ft of that space
- Residential District One-LakefrontThe unit must be carved out of the space within the house, not built as a separate building, and may not exceed 500 sq ft of that space
- Residential District TwoThe unit must be carved out of the space within the house, not built as a separate building, and may not exceed 500 sq ft of that space
- Agriculture and Open Space DistrictThe unit must be carved out of the space within the house, not built as a separate building, and may not exceed 500 sq ft of that space
- Rural Agriculture DistrictThe unit must be carved out of the space within the house, not built as a separate building, and may not exceed 500 sq ft of that space
- Multifamily Residential District ThreeThe unit must be carved out of the space within the house, not built as a separate building, and may not exceed 500 sq ft of that space
- Multifamily Residential District FourThe unit must be carved out of the space within the house, not built as a separate building, and may not exceed 500 sq ft of that space
- Mobile Home Residential District FiveThe unit must be carved out of the space within the house, not built as a separate building, and may not exceed 500 sq ft of that space
- Public Facilities DistrictThe unit must be carved out of the space within the house, not built as a separate building, and may not exceed 500 sq ft of that space
- Recreational Facilities DistrictThe unit must be carved out of the space within the house, not built as a separate building, and may not exceed 500 sq ft of that space
- Neighborhood Business DistrictThe unit must be carved out of the space within the house, not built as a separate building, and may not exceed 500 sq ft of that space
- General Business DistrictThe unit must be carved out of the space within the house, not built as a separate building, and may not exceed 500 sq ft of that space
- Motor Vehicle Service DistrictThe unit must be carved out of the space within the house, not built as a separate building, and may not exceed 500 sq ft of that space
- Light Industrial DistrictThe unit must be carved out of the space within the house, not built as a separate building, and may not exceed 500 sq ft of that space
- General Industrial DistrictThe unit must be carved out of the space within the house, not built as a separate building, and may not exceed 500 sq ft of that space
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 National Grid 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 rentalsNo local short-term-rental law on record - which is not the same as permission. The town has no local short-term rental law. That is not the same as permission, so confirm with the town before counting on renting a home short term. Separate question from whether you can build the unit.
- Zoning codeecode360.com/7076053
- Building dept(716) 217-3500
Sizing up a specific parcel in Evans?
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 Evans runs $204–268/sq ft, about $370k–480k at 1,800 sq ft , plus roughly $751 for a conforming lot. See what it costs to build a house in Evans.
ADU cost in nearby towns
All Erie County towns: Buffalo (City) · Lackawanna (City) · Tonawanda (City) · Alden · Amherst · Aurora · Boston · Brant · Cheektowaga · Clarence · Colden · Collins · Concord · Eden · Elma · Grand Island · Hamburg · Holland · Lancaster · Marilla · Newstead · North Collins · Orchard Park · Sardinia · Tonawanda · Wales · West Seneca · Akron (Village) · Alden (Village) · Angola (Village) · Blasdell (Village) · Depew (Village) · East Aurora (Village) · Farnham (Village) · Gowanda (Village) · Hamburg (Village) · Kenmore (Village) · Lancaster (Village) · North Collins (Village) · Orchard Park (Village) · Sloan (Village) · Springville (Village) · Williamsville (Village)
More on Evans: Can you build an ADU here? · Zoning for new construction · Erie County build cost
ADU cost in Evans: common questions
How much does it cost to build an ADU in Evans, NY?
An 800 sq ft accessory dwelling unit in Town of Evans 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 Evans?
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 Evans?
Town of Evans has 17 districts. 8 districts prohibit ADUs, 8 require a special-use permit. 1 district has incomplete data - verify with the building department at (716) 217-3500. Check the specific address with the free ADU checker before you spend money on design.
Can I rent an ADU in Evans short term?
No local short-term-rental law on record - which is not the same as permission for Town of Evans. 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 Erie 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 Town of Evans vary by district and often carry exceptions this page does not show; zoning last reviewed 2026-09-10; verify with the building department at (716) 217-3500 before relying on any answer. Sources: the Offsite / Aldo cost engine and zoning dataset.