Can you build an ADU in Lancaster, NY?

R-1 Residence District - The 6,000 sq ft is per dwelling unit here, so a duplex needs 12,000 sq ft. The side yard shown cannot be taken on both sides: the two side yards must total at least 11 ft and neither may be under 4 ft, and a multiple dwelling takes at least 10 ft on each side.

• Lot width grows by 30 ft for each additional dwelling unit
• The rear yard is 25% of the lot depth and never less than 25 ft, so the figure shown is its floor
• The front yard must be at least the average of the existing buildings within 150 ft either way, though nothing forces more than 50 ft
• On a site of an acre or more a single house needs at least 6,000 sq ft and a two-family at least 9,500 sq ft
• On a site of an acre or more the Village Board may cut a planned apartment dwelling group to 3,500 sq ft per unit on written Planning Commission approval
• That cut requires a site plan showing building coverage no greater than a single- or two-family house would take

R-2 Residence District - The 6,000 sq ft buys either one or two dwelling units, and each unit beyond the second costs a further 2,000 sq ft, so a duplex needs no more land than a single house and a triplex needs 8,000 sq ft.

• The two side yards must total at least 11 ft and neither may be under 4 ft, so the figure shown cannot be taken on both sides
• Lot width grows by 15 ft for each additional dwelling unit, capped at 200 ft
• The rear yard is 25% of the lot depth and never less than 25 ft, so the figure shown is its floor
• A building over 30 ft tall is priced by storey count instead: 1,100 sq ft per unit at four storeys, 1,000 at five, 900 at six, 800 at seven and 650 at eight
• On a site of an acre or more a two-family needs 8,000 sq ft and a three-family 10,000 sq ft
• The front yard must be at least the average of the existing buildings within 150 ft either way, though nothing forces more than 50 ft

R-2A Residence District - The 6,000 sq ft buys either one or two dwelling units, and each unit beyond the second costs a further 2,000 sq ft, so a duplex needs no more land than a single house and a triplex needs 8,000 sq ft.

• The two side yards must total at least 11 ft and neither may be under 4 ft, so the figure shown cannot be taken on both sides
• Lot width grows by 15 ft for each additional dwelling unit, capped at 200 ft
• The rear yard is 25% of the lot depth and never less than 25 ft, so the figure shown is its floor
• A building over 30 ft tall is priced by storey count instead: 1,100 sq ft per unit at four storeys, 1,000 at five, 900 at six, 800 at seven and 650 at eight
• A principal building that is not a dwelling takes 15 ft on each side, or half the building height if greater
• The front yard must be at least the average of the existing buildings within 150 ft either way, though nothing forces more than 50 ft

Mixed Use Core District - The front setback is a build-to zone of 0 to 10 ft, not a minimum, and 90% of the lot frontage must be occupied by building, so a building must come to the back of the sidewalk rather than stand back from it.

• No street-facing building may run more than 200 ft
• The ground storey must be at least 14 ft tall and at least 70% transparent, and an upper storey at least 9 ft and 20% transparent
• No blank wall may run more than 15 ft
• The district sets a minimum lot area of 0 sq ft, a minimum lot width of 0 ft and a 0 ft minimum from a common lot line; what it controls is where the building meets the street
• The 5 ft shown is the minimum from an alley
• A tenth of the site must be outdoor amenity space, and parking stands 20 ft back from the street

Mixed Use 1 District - Height is capped twice over: 2.5 storeys and 35 ft to the roof, but only two storeys and 24 ft to the top plate. The front setback is a build-to zone of 0 to 10 ft, with 75% of the lot frontage occupied by building.

• A storey counts as a half storey where dormers cover no more than half the front or side building length, and as a full one above that
• No street-facing building may run more than 200 ft
• A ground floor in residential use sits 2 to 5 ft above grade, and a non-residential one 0 to 2 ft
• The district sets a minimum lot area of 0 sq ft, a minimum lot width of 0 ft and a 0 ft minimum from a common lot line; what it controls is where the building meets the street
• The 5 ft shown is the minimum from an alley, a tenth of the site must be outdoor amenity space, and parking stands 20 ft back from the street

Mixed Use 2 District - The front setback is a build-to zone of 10 to 30 ft, a maximum as well as a minimum, with 30% of the lot frontage occupied by building.

• Height is capped twice over: 2.5 storeys and 35 ft to the roof, but only two storeys and 24 ft to the top plate
• A storey counts as a half storey where dormers cover no more than half the front or side building length, and as a full one above that
• No street-facing building may run more than 60 ft
• A ground floor in residential use sits 2 to 5 ft above grade, and a non-residential one 0 to 2 ft
• The district sets a minimum lot area of 0 sq ft, a minimum lot width of 0 ft and a 0 ft minimum from a common lot line
• The 5 ft shown is the minimum from an alley, a tenth of the site must be outdoor amenity space, and parking stands 20 ft back from the street

Business District - Against a residential lot the side yard is 30 ft, or the height of the building if greater, unless the building stays under 15 ft tall and a maintained visual barrier of fencing or planting is furnished, in which case it may be as little as five feet.

• The rear yard works the same way: 30 ft or the building height against a residential lot, or ten feet under the same barrier condition
• No side yard is required between commercial lots, though any side yard actually provided must be at least five feet, and 12 ft where it is used for vehicle ingress or egress
• A non-residential building has no lot area and no lot width, and is sized only by the open space and off-street parking regulations
• Where the building contains dwellings the residential rule applies instead: 6,000 sq ft for either one or two units plus 2,000 sq ft for each additional, on 60 ft of width
• A building over 30 ft tall is priced by storey count, from 1,100 sq ft per unit at four storeys down to 650 sq ft at eight
• Open off-street parking may occupy any required yard except within ten feet of a street line or of a lot in a residential district

Open Space Zone - The district's purpose is passive recreational enjoyment of land near Cayuga Creek. Substantial development in the way of buildings or structures is not desirable, as topography, drainage, floodplain and other natural conditions would put a building and its occupants at risk.

• The land is designated for park, recreation and open space use and is meant to stay that way
• Permitted uses are public parks and playgrounds, pedestrian and bicycle trails and similar recreation uses
• Every development must go through site plan review

Manufacturing District - The side and rear yards shown apply between industrial lots, and both rise to 50 ft against a residential lot. The front yard doubles to 50 ft where it is used for off-street parking or where the lot lies opposite a lot in a residential district.

• A non-residential building has no lot area and no lot width, and is sized only by the open space and off-street parking regulations
• Open off-street parking may occupy any required yard except within ten feet of a street line or of a lot in a residential district
• An accessory building may reach 30 ft, the same as a principal one

Industrial Park District - The front yard rises to 50 ft where it is used for off-street parking or where the lot lies opposite a lot in a residential district, and the side and rear yards, which apply between industrial lots, both rise to 50 ft against a residential lot.

• A non-residential building is sized only by the open space and off-street parking regulations
• An accessory building may reach 30 ft, the same as a principal one