Greece · ADU cost
What it costs to build an ADU in Greece, NY
An 800 sq ft accessory dwelling unit in Greece 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 Greece maps 12 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 Greece
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 Greece 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 |
|---|---|---|---|---|
| Single-Family Residential (R1-44) | 1.01 ac | 70 / 20 / 70 ft | — | Occupancy restricted |
| Single-Family Residential (R1-18) | 0.41 ac | 50 / 10 / 50 ft | — | Occupancy restricted |
| Single-Family Residential (R1-10) | 0.23 ac | 25 / 6 / 40 ft | — | Occupancy restricted |
| Single-Family Residential — Established Neighborhood (R1-E) | — | 25 / 6 / 30 ft | — | Occupancy restricted |
| Multiple-Family Residential (RM) | 3 ac | 100 / 50 / 50 ft | — | No |
| Senior Citizen Residential (RS) | 5 ac | 100 / 50 / 50 ft | — | No |
| Professional Business (BP) | 0.28 ac | 30 / 15 / 15 ft | 40 ft | No |
| Restricted Business (BR) | 0.34 ac | 30 / 15 / 15 ft | — | No |
| General Business (BG) | 0.46 ac | 30 / 20 / 20 ft | — | No |
| Flexible Office-Industrial (FOI) | 1 ac | 100 / 0 / 0 ft | — | No |
| Light Industrial (IL) | 3 ac | 100 / 25 / 25 ft | — | No |
| General Industrial (IG) | 5 ac | 100 / 25 / 25 ft | — | No |
Single-Family Residential (R1-44) - The 70 ft front setback is a floor: on a lot adjoining lots with buildings on the same side of the street, the required front setback is the greater of that figure and the neighbourhood average (§ 211-11D(1)). The planning board may require cluster development here.
- A corner lot takes 55,000 sq ft of area and 185 ft of width, larger than the interior lot figures shown.
- A minimum front lot line of 50 ft applies in addition to the lot width.
- On a Town highway with a right-of-way under 50 ft, front setback is measured from the centreline plus 30 ft; on a Monroe County highway under 80 ft other than Dewey Avenue, plus 50 ft.
- On Deming Street, Gates-Greece Town Line Road, Janes Road, Ling Road, Maiden Lane, Peck Road or Post Avenue, measure from the centreline and add 45 ft.
- Minimum dwelling area: 1,500 sq ft for one storey; 1,250 sq ft first floor and 2,000 sq ft total at one and a half storeys; 1,100 sq ft first floor and 2,200 sq ft total at two storeys.
- Accessory building floor area is capped at 800 sq ft on a lot up to 16,000 sq ft, 1,000 sq ft from 16,000 sq ft to an acre, and 1,250 sq ft above an acre, and never more than the principal structure.
Single-Family Residential (R1-18) - The 50 ft front setback is a floor. On a lot adjoining built lots on the same side of the street, the front setback is the greater of that figure and the neighbourhood average, and on several classes of road it is measured from the centreline with extra distance added.
- Corner lots take a larger lot than interior ones: 22,500 sq ft of area and 125 ft of width.
- The Planning Board may require cluster development here, so a conventional subdivision layout is not guaranteed.
- A minimum front lot line of 50 ft applies in addition to the lot width requirement.
- Minimum dwelling unit area varies with storeys: 1,000 sq ft on the first floor and 1,500 sq ft total for one-and-a-half storeys, 1,000 sq ft on the first floor and 1,700 sq ft total for two storeys.
- Add 30 ft from the centreline on a Town highway with a right-of-way under 50 ft, and 50 ft on a Monroe County highway with a right-of-way under 80 ft other than Dewey Avenue.
- Add 45 ft on Deming Street, Gates-Greece Town Line Road, Janes Road, Ling Road, Maiden Lane, Peck Road or Post Avenue, and 10 ft where the lot contains a private road or easement serving other lots.
Single-Family Residential (R1-10) - The 25 ft front setback is a floor. On a lot adjoining lots with buildings on the same side of the street, the front setback is the greater of the district figure and the neighborhood average, and on some roads it is measured from the road centerline with feet added.
- A corner lot must have 12,500 sq ft of area and 90 ft of width, larger than the interior lot figures shown.
- On a Town highway with a right-of-way under 50 ft, measure from the centerline and add 30 ft; on a Monroe County highway with a right-of-way under 80 ft other than Dewey Avenue, add 50 ft.
- Where the lot contains a private road, driveway or easement serving other lots, the front setback is measured from that centerline plus 10 ft.
- A minimum front lot line of 40 ft applies on top of the lot width requirement.
- The Planning Board may require cluster development here, so a conventional subdivision is not guaranteed.
- Minimum dwelling area is 1,000 sq ft for one storey, 850 sq ft on the first floor with 1,100 sq ft total for one and a half storeys, and 700 sq ft on the first floor with 1,200 sq ft total for two.
Single-Family Residential — Established Neighborhood (R1-E) - This district publishes no minimum lot area, width or depth. Each is the neighbourhood average taken from the adjoining lot in both directions on the same side of the street, and a corner lot must reach 125% of that average in area and width.
- A minimum front lot line of 40 ft is the one fixed lot dimension.
- The rear yard is 30% of the lot depth or 30 ft, whichever is greater, so a deeper lot gives up more than the figure shown.
- The side yard is 10% of the lot width, never under 6 ft and never over 10 ft.
- Front setback is measured from the road centreline: add 30 ft on a Town highway with a right-of-way under 50 ft, or 50 ft on a Monroe County highway under 80 ft other than Dewey Avenue.
- Add 45 ft from the centreline on Deming Street, Gates-Greece Town Line Road, Janes Road, Ling Road, Maiden Lane, Peck Road or Post Avenue.
- Accessory building floor area is capped at 800 sq ft on a lot up to 16,000 sq ft, 1,000 sq ft from 16,000 sq ft to an acre and 1,250 sq ft above an acre, and cannot exceed the principal structure.
Multiple-Family Residential (RM) - The 3 acre figure is a minimum district area, not a lot minimum, and the Town Board may waive it. Yield is set by the density limit instead.
- The three setback figures are not front, side and rear: the 100 ft setback applies from a street right-of-way exterior to the district, dropping to 25 ft for a single-family home.
- The setback from the boundary of another RM or RS district is 25 ft, and the setback from the boundary of any other district is 50 ft.
- The front setback is measured from the road centreline: add 30 ft on a Town highway with a right-of-way under 50 ft, and add 45 ft on Deming Street, Janes Road, Ling Road and other named roads.
- On a Monroe County highway with a right-of-way under 80 ft other than Dewey Avenue, add 50 ft. Where the lot contains a private road, driveway or easement serving other lots, add 10 ft.
- A minimum front lot line of 50 ft applies, and setbacks are measured to the foundation.
- Parking is allowed inside the 100 ft setback but no closer than 50 ft to the street right-of-way, and no parking area or driveway may come within 30 ft of a lot line.
Senior Citizen Residential (RS) - The 5 acre figure is a minimum district area rather than a lot minimum, and the Town Board may waive it, so yield comes from the density instead: 15 dwelling units per acre, or 20 residential units per acre, either of which the Town Board may increase.
- The three setback figures are not front, side and rear. The 100 ft setback applies from a street right-of-way exterior to the district, dropping to 25 ft for a single-family home.
- A 25 ft setback applies from the boundary of another RM or RS district, and 50 ft from the boundary of any other district.
- A three-bedroom unit is not permitted in RS.
- Front setback is measured from the road centreline on some roads: add 30 ft on a Town highway with a right-of-way under 50 ft, or 50 ft on a Monroe County highway under 80 ft other than Dewey Avenue.
- A minimum front lot line of 50 ft applies, and no parking area or driveway may come within 30 ft of a lot line.
- The Town Board may increase the three-story limit under § 211-13D or § 211-14D(1). An accessory building is limited to one story and may never exceed the tallest principal building.
Professional Business (BP) - The 30 ft front setback is a minimum only, with the neighbourhood average acting as the maximum, and on several classes of road it is measured from the road centreline with 30 ft, 45 ft or 50 ft added.
- A corner lot takes 15,000 sq ft on 100 ft of width in place of the interior lot figures shown.
- A minimum front lot line of 50 ft applies.
- No parking area or driveway may come within 20 ft of a front lot line, reducible by the Planning Board to 10 ft behind a decorative wall no more than 3 ft high.
- No parking area or driveway may come within 20 ft of a residential district, reducible to 10 ft behind a solid wall at least 6 ft high.
- Height is capped at two storeys as well as 40 ft.
- The 1,000 sq ft figure is a minimum gross floor area for the principal building, a floor on size rather than a cap.
Restricted Business (BR) - The 30 ft front setback is a minimum only. The maximum is the neighborhood average, so a building set too far back fails as surely as one set too close, and on several classes of road the front setback is measured from the road centerline with extra distance added.
- A corner lot takes 18,000 sq ft of lot area on 100 ft of width, in place of the interior lot figures shown.
- On a town highway with a right-of-way under 50 ft, measure from the centerline and add 30 ft; on a Monroe County highway with a right-of-way under 80 ft other than Dewey Avenue, add 50 ft.
- On Deming Street, Gates-Greece Town Line Road, Janes Road, Ling Road, Maiden Lane, Peck Road or Post Avenue, add 45 ft. A private road, driveway or easement serving other lots adds 10 ft.
- A minimum front lot line of 50 ft applies.
- No parking area or driveway may come within 20 ft of a front lot line, reducible by the Planning Board to 10 ft behind a decorative wall no more than 3 ft high.
- No parking area or driveway may come within 20 ft of a residential district, reducible to 10 ft behind a solid wall at least 6 ft high.
General Business (BG) - The 30 ft front setback is only the minimum: the maximum is the neighbourhood average, so a building set too far back fails as surely as one set too close. On several classes of road the front setback is measured from the centreline with added distance.
- A corner lot takes 24,000 sq ft on 100 ft of width, in place of the interior lot figures shown.
- A minimum front lot line of 50 ft applies.
- On a Town highway with a right-of-way under 50 ft, measure from the centreline and add 30 ft; on a Monroe County highway with a right-of-way under 80 ft other than Dewey Avenue, add 50 ft.
- On Deming Street, Gates-Greece Town Line Road, Janes Road, Ling Road, Maiden Lane, Peck Road or Post Avenue, measure from the centreline and add 45 ft.
- No parking area or driveway may come within 20 ft of a front lot line, reducible by the Planning Board to 10 ft behind a decorative wall no more than 3 ft high.
- No parking area or driveway may come within 20 ft of a residential district, reducible to 10 ft behind a solid wall at least 6 ft high.
Flexible Office-Industrial (FOI) - Where the lot adjoins a residential district, both the side and rear setbacks rise to 100 ft. The zero side and rear figures apply only where the neighbouring land is in a nonresidential district, so what sits next door drives the buildable area.
- The 100 ft front setback runs from the street right-of-way, but on several classes of road it is measured from the road centre line with extra distance added, which can shift it by tens of feet.
- Add 30 ft on a Town highway with a right-of-way under 50 ft, and 45 ft on Deming Street, Gates-Greece Town Line Road, Janes Road, Ling Road, Maiden Lane, Peck Road or Post Avenue.
- Add 50 ft on a Monroe County highway with a right-of-way under 80 ft other than Dewey Avenue, and 10 ft from the centre line of a private road, driveway or easement on the lot that serves other lots.
- No parking area or driveway may come within 50 ft of a residential district.
- A parking area or driveway must also stay 25 ft back from a street right-of-way line, except for a driveway giving direct access to a public street.
- Setbacks must increase where the State Building Code requires it for occupancy, materials, height or fire resistance, and may drop to zero next to a nonresidential district where that code permits.
Light Industrial (IL) - The 25 ft side and rear setbacks apply where the lot adjoins a nonresidential district. Where the lot adjoins a residential district, both rise to 100 ft.
- On a Town highway with a right-of-way under 50 ft, measure the front setback from the centerline and add 30 ft; on a Monroe County highway under 80 ft other than Dewey Avenue, add 50 ft.
- An added 45 ft applies on Deming Street, Gates-Greece Town Line Road, Janes Road, Ling Road, Maiden Lane, Peck Road and Post Avenue, measured from the centerline.
- Where the lot contains a private road, driveway or easement serving other lots, the front setback is measured from its centerline plus 10 ft.
- A minimum front lot line of 50 ft applies, and the 1,000 sq ft minimum is a gross floor area for the principal building.
- No parking area or driveway may come within 50 ft of a residential district; in IL none may sit within 25 ft of a street right-of-way line, except a driveway giving direct access to a public street.
- Setbacks increase where the State Building Code requires it for occupancy, materials, height or fire resistance, and a setback from a nonresidential district may be reduced to zero where it permits.
General Industrial (IG) - Side and rear setbacks rise to 100 ft where the lot adjoins a residential district, instead of the 25 ft that applies next to a nonresidential district. The front setback is measured from a road centreline and enlarged on several classes of road.
- On a Town highway with a right-of-way under 50 ft, measure from the centreline and add 30 ft; on a Monroe County highway with a right-of-way under 80 ft other than Dewey Avenue, add 50 ft.
- Add 45 ft on Deming Street, Gates-Greece Town Line Road, Janes Road, Ling Road, Maiden Lane, Peck Road or Post Avenue; where the lot contains a private road or easement serving other lots, add 10 ft.
- No parking area or driveway may come within 50 ft of a residential district.
- No parking area or driveway may sit closer than 50 ft to a street right-of-way line, except a driveway giving direct access to a public street.
- A minimum front lot line of 50 ft applies.
- Setbacks must increase where the State Building Code requires it for materials, height or fire resistance, and may drop to zero from a nonresidential district where that code permits.
Size limits on record in Greece
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 Greece:
- Single-Family Residential (R1-44)Size cap: the apartment may not exceed 30% of the dwelling's gross floor area, excluding attached garages, or 600 square feet, whichever is less.
- Single-Family Residential (R1-18)Size cap: the apartment may not exceed 30% of the dwelling's gross floor area, excluding attached garages, or 600 square feet, whichever is less.
- Single-Family Residential (R1-10)Size cap: the apartment may not exceed 30% of the dwelling's gross floor area, excluding attached garages, or 600 square feet, whichever is less.
- Single-Family Residential — Established Neighborhood (R1-E)Size cap: the apartment may not exceed 30% of the dwelling's gross floor area, excluding attached garages, or 600 square feet, whichever is less.
- Multiple-Family Residential (RM)Size cap: the apartment may not exceed 30% of the dwelling's gross floor area, excluding attached garages, or 600 square feet, whichever is less.
- Senior Citizen Residential (RS)Size cap: the apartment may not exceed 30% of the dwelling's gross floor area, excluding attached garages, or 600 square feet, whichever is less.
- Professional Business (BP)Size cap: the apartment may not exceed 30% of the dwelling's gross floor area, excluding attached garages, or 600 square feet, whichever is less.
- Restricted Business (BR)Size cap: the apartment may not exceed 30% of the dwelling's gross floor area, excluding attached garages, or 600 square feet, whichever is less.
- General Business (BG)Size cap: the apartment may not exceed 30% of the dwelling's gross floor area, excluding attached garages, or 600 square feet, whichever is less.
- Flexible Office-Industrial (FOI)Size cap: the apartment may not exceed 30% of the dwelling's gross floor area, excluding attached garages, or 600 square feet, whichever is less.
- Light Industrial (IL)Size cap: the apartment may not exceed 30% of the dwelling's gross floor area, excluding attached garages, or 600 square feet, whichever is less.
- General Industrial (IG)Size cap: the apartment may not exceed 30% of the dwelling's gross floor area, excluding attached garages, or 600 square feet, whichever is less.
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 with local rules. Renting a home short term in the Town of Greece requires a short-term rental property permit from the Town under § 162A-7. That requirement sits in Chapter 162A, Rental Properties, separate from the zoning chapter. Separate question from whether you can build the unit.
- Zoning codeecode360.com/10840054
- Building dept(585) 723-2443
Sizing up a specific parcel in Greece?
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 Greece runs $204–268/sq ft, about $370k–480k at 1,800 sq ft , plus roughly $4,642 for a conforming lot. See what it costs to build a house in Greece.
ADU cost in nearby towns
All Monroe County towns: Rochester (City) · Brighton · Chili · Clarkson · Gates · Hamlin · Henrietta · Irondequoit · Mendon · Ogden · Parma · Penfield · Perinton · Pittsford · Riga · Rush · Sweden · Webster · Wheatland · East Rochester (Village) · Brockport (Village) · Churchville (Village) · Fairport (Village) · Hilton (Village) · Honeoye Falls (Village) · Pittsford (Village) · Scottsville (Village) · Spencerport (Village) · Webster (Village)
More on Greece: Can you build an ADU here? · Zoning for new construction · Monroe County build cost
ADU cost in Greece: common questions
How much does it cost to build an ADU in Greece, NY?
An 800 sq ft accessory dwelling unit in Town of Greece 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 Greece?
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 Greece?
Town of Greece has 12 districts. 8 districts prohibit ADUs, 4 allow them with occupancy restrictions. Check the specific address with the free ADU checker or confirm with the building department at (585) 723-2443 before you spend money on design.
Can I rent an ADU in Greece short term?
Short-term rentals allowed with local rules for Town of Greece. 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 Town of Greece vary by district and often carry exceptions this page does not show; zoning last reviewed 2026-08-07; verify with the building department at (585) 723-2443 before relying on any answer. Sources: the Offsite / Aldo cost engine and zoning dataset.