Can you build an ADU in Grand Island, NY?

Low-Density Single-Family Residential District - A setback measured from the centre of the right-of-way governs on eighteen named roads and overrides the district front yard wherever it is greater: 115 ft on Grand Island Boulevard, 100 ft on Alt Boulevard, Baseline, Whitehaven and most of Stony Point Road.

• On East River Road that setback is 90 ft, and on the other named roads 80 ft (§ 407-18A)
• The three acres cannot be taken in any shape: a lot must also be 140 ft wide at the street and 250 ft deep
• On a shoreline lot the setback from the top of the river bank is the average of the two adjoining structures, or a match to the single one that is built, and never less than the district rear yard

Single-Family Residential District - A setback measured from the centre of the right-of-way governs on eighteen named roads and overrides the district front yard wherever it is greater: 115 ft on Grand Island Boulevard, 100 ft on Alt Boulevard, Baseline, Whitehaven and most of Stony Point Road.

• On East River Road that setback is 90 ft, and on the other named roads 80 ft (§ 407-18A)
• The size figure here is the buildable area each dwelling unit takes, 30,000 sq ft, rather than a lot area, and for a single house the two come to the same thing
• Shape is controlled separately: at least 120 ft of frontage and 250 ft of depth
• On a shoreline lot the setback from the top of the river bank is the average of the two adjoining structures, or a match to the single one that is built, and never less than the district rear yard

Single-Family Residential District - A setback measured from the centre of the right-of-way governs on eighteen named roads and overrides the district front yard wherever it is greater: 115 ft on Grand Island Boulevard, 100 ft on Alt Boulevard, Baseline, Whitehaven and most of Stony Point Road.

• On East River Road that setback is 90 ft, and on the other named roads 80 ft (§ 407-18A)
• The size figure here is the buildable area each dwelling unit takes, 20,000 sq ft, rather than a lot area, and for a single house the two come to the same thing
• Shape is controlled separately: at least 100 ft of frontage and 200 ft of depth
• On a shoreline lot the setback from the top of the river bank is the average of the two adjoining structures, or a match to the single one that is built, and never less than the district rear yard

Medium-Density Single-Family Residential District - A setback measured from the centre of the right-of-way governs on eighteen named roads and overrides the district front yard wherever it is greater: 115 ft on Grand Island Boulevard, 100 ft on Alt Boulevard, Baseline, Whitehaven and most of Stony Point Road.

• On East River Road that setback is 90 ft, and on the other named roads 80 ft (§ 407-18A)
• The size figure here is the buildable area each dwelling unit takes, 12,800 sq ft, rather than a lot area, and for a single house the two come to the same thing
• Shape is controlled separately: at least 80 ft of frontage and 160 ft of depth
• On a shoreline lot the setback from the top of the river bank is the average of the two adjoining structures, or a match to the single one that is built, and never less than the district rear yard

High-Density Single-Family Residential District - A setback measured from the centre of the right-of-way governs on eighteen named roads and overrides the district front yard wherever it is greater: 115 ft on Grand Island Boulevard, 100 ft on Alt Boulevard, Baseline, Whitehaven and most of Stony Point Road.

• On East River Road that setback is 90 ft, and on the other named roads 80 ft (§ 407-18A)
• The size figure here is the buildable area each dwelling unit takes, 9,450 sq ft, rather than a lot area, and for a single house the two come to the same thing
• Shape is controlled separately: at least 70 ft of frontage and 135 ft of depth
• On a shoreline lot the setback from the top of the river bank is the average of the two adjoining structures, or a match to the single one that is built, and never less than the district rear yard

Attached/Detached Single-Family Residential District - The five acres is the minimum size of the development, not of a lot inside it. Yield comes from the 8,400 sq ft of buildable area each dwelling unit consumes.

• A development reached by private roads is priced lower, at 6,600 sq ft per unit on 60 ft of frontage rather than 8,400 on 70 ft
• No more than four dwelling units may sit in one contiguous structure, no structure may run more than 160 ft along its facade, and structures must stand 60 ft apart
• A common parking area must be 12 ft from any lot line, and any part of the development facing a residentially zoned lot must stand 30 ft back
• Minimum dwelling size runs 650 sq ft for one bedroom, 860 for two and 1,000 for three, with a further 120 sq ft for every bedroom beyond that
• A setback measured from the centre of the right-of-way governs on eighteen named roads and overrides the district front yard wherever it is greater
• That road setback is 115 ft on Grand Island Boulevard, 100 ft on Alt Boulevard, Baseline, Whitehaven and most of Stony Point Road, 90 ft on East River Road and 80 ft on the rest

Attached/Detached Waterfront Single-Family Residential District - The five acres is the minimum size of the development, not of a lot inside it. Yield comes from the 8,400 sq ft of buildable area each dwelling unit consumes.

• The 20 ft rear yard is the yard that faces the water on a river lot
• A development reached by private roads is priced at 6,600 sq ft per unit on 60 ft of frontage instead
• No more than four dwelling units may sit in one contiguous structure, no structure may run more than 160 ft along its facade, and structures must stand 60 ft apart
• Minimum dwelling size runs 650 sq ft for one bedroom, 860 for two and 1,000 for three, with a further 120 sq ft for every bedroom beyond that
• On a shoreline lot the setback from the top of the river bank is the average of the two adjoining structures, or a match to the single one that is built, and never less than the district rear yard
• A setback measured from the centre of the right-of-way governs on eighteen named roads and overrides the district front yard wherever it is greater

Multiple-Family Residential District - The three acres is the minimum size of the development, not of a lot inside it. Yield comes from the 3,500 sq ft of buildable area each dwelling unit consumes.

• The parcel must also be at least 200 ft wide and 200 ft deep
• No building may run more than 160 ft along its facade, main buildings must stand 60 ft apart and other buildings 20 ft
• Common parking must be 25 ft back at the front and 10 ft at the rear, excluding enclosed garages and carports
• Minimum dwelling size runs 650 sq ft for one bedroom, 860 for two and 1,000 for three, with a further 120 sq ft for every bedroom beyond that
• A setback measured from the centre of the right-of-way governs on eighteen named roads and overrides the district front yard wherever it is greater
• That road setback is 115 ft on Grand Island Boulevard, 100 ft on Alt Boulevard, Baseline, Whitehaven and most of Stony Point Road, 90 ft on East River Road and 80 ft on the rest

General Business District, Hamlet Business District - A setback measured from the centre of the right-of-way governs on eighteen named roads and overrides the district front yard wherever it is greater: 115 ft on Grand Island Boulevard, 100 ft on Alt Boulevard, Baseline, Whitehaven and most of Stony Point Road.

• On East River Road that setback is 90 ft, and on the other named roads 80 ft (§ 407-18A)
• The 20,000 sq ft figure is the land a dwelling consumes here, not a floor on the size of a commercial lot
• A lot must be 100 ft of frontage, 100 ft wide and 200 ft deep
• Anything within 50 ft of a residentially zoned lot must stand back that far

Waterfront Business District - A setback measured from the centre of the right-of-way governs on eighteen named roads and overrides the district front yard wherever it is greater: 115 ft on Grand Island Boulevard, 100 ft on Alt Boulevard, Baseline, Whitehaven and most of Stony Point Road.

• On East River Road that setback is 90 ft, and on the other named roads 80 ft (§ 407-18A)
• The 20 ft yards also apply against a residentially zoned lot
• A lot must be 100 ft of frontage, 100 ft wide and 200 ft deep
• On a shoreline lot the setback from the top of the river bank is the average of the two adjoining structures, or a match to the single one that is built, and never less than the district rear yard

Commercial Recreational Facilities District - Frontage and width are different figures here: 100 ft of frontage on the street but 200 ft of width, so a lot may neck down where it meets the road.

• Every yard is 50 ft, including the setback from a residentially zoned lot
• The 35 ft height cap applies to buildings; an amusement park ride or attraction may reach 100 ft
• A setback measured from the centre of the right-of-way governs on eighteen named roads and overrides the district front yard wherever it is greater
• That road setback is 115 ft on Grand Island Boulevard, 100 ft on Alt Boulevard, Baseline, Whitehaven and most of Stony Point Road, 90 ft on East River Road and 80 ft on the rest

Light Industrial and Research District, Industrial District - A setback measured from the centre of the right-of-way governs on eighteen named roads and overrides the district front yard wherever it is greater: 115 ft on Grand Island Boulevard, 100 ft on Alt Boulevard, Baseline, Whitehaven and most of Stony Point Road.

• On East River Road that setback is 90 ft, and on the other named roads 80 ft (§ 407-18A)
• A lot must be 150 ft of frontage, 150 ft wide and 300 ft deep
• Anything within 50 ft of a residentially zoned lot must stand back that far

Mining/Excavation Overlay District - This is an overlay, applied on top of whatever district the land already carries, so its 100 ft yards sit alongside the underlying district's standards rather than replacing them. Those yards are measured to the top of the excavated area, not to a building.

• Fifty feet of frontage is the only shape requirement
• A setback measured from the centre of the right-of-way governs on eighteen named roads and overrides the district front yard wherever it is greater
• That road setback is 115 ft on Grand Island Boulevard, 100 ft on Alt Boulevard, Baseline, Whitehaven and most of Stony Point Road, 90 ft on East River Road and 80 ft on the rest

North Business District, South Business District - Residential density is the standard that binds here, not lot size: attached houses, duplexes and multifamily developments are permitted by right at eight units per acre or fewer, and a special permit lifts attached and multifamily to between nine and twelve.

• Lot area, width, depth, side and rear yards and coverage are settled by the design and performance standards at § 407-13 and at site plan review
• The Town Board may approve a plan with setbacks smaller than the town's named-road setback would otherwise require (§ 407-18B)

Central Business District - This district sets a minimum residential density as well as a maximum: attached houses and multifamily developments are permitted by right at no fewer than nine and no more than sixteen units per acre, so a thin scheme is as non-conforming as an overbuilt one.

• Above sixteen units per acre a special permit is required, and no upper figure is named
• Lot area, width, depth, side and rear yards and coverage are settled by the design and performance standards at § 407-13 and at site plan review
• The Town Board may approve a plan with setbacks smaller than the town's named-road setback would otherwise require (§ 407-18B)

Open Space District - Setbacks here are determined at site plan review. A setback measured from the centre of the right-of-way still governs on eighteen named roads: 115 ft on Grand Island Boulevard, 100 ft on Alt Boulevard, Baseline, Whitehaven and most of Stony Point Road.

• On East River Road that setback is 90 ft, and on the other named roads 80 ft (§ 407-18A)