Can you build an ADU in New Hempstead, NY?

One-Family Residence - The 20% coverage figure is the maximum impervious surface ratio, counting drives, terraces and every other hard surface along with the buildings. A building must meet the floor area ratio or a 3,750 sq ft building coverage cap, not both, and the owner chooses which.

• An average density subdivision is a second complete row: 0.9183 acres on 150 ft of width, 25 ft to each side with 70 ft for the pair. Minimum lot frontage is 100 ft, separate from lot width.
• An active adult community, a special permit use under § 290-57, is capped at 120 units; a single-story home sits on 0.1148 acres with 10 ft to each side, two storeys and 10% coverage.
• A respite facility for disabled children needs 10 acres, 435,600 sq ft, on 250 ft of width with 30 ft each side; a preexisting building 15 feet from a line, or an accessory 3 feet, is exempt.
• No land inside an access easement or right-of-way counts toward a minimum lot area, and the lot area rules bind existing easements as well as proposed ones.
• Only a quarter of land under water, in a village wetland, hundred-year floodplain or open drainage easement, under overhead utility lines or unexcavated over 25% slope counts toward the lot minimum.
• Only three quarters of land in a conservation easement, a piped drainage easement, a sewer easement or an underground utility easement counts toward a minimum lot area.

One-Family Residence - The 20% coverage figure is the maximum impervious surface ratio, counting drives, terraces and every other hard surface along with the buildings. A building must meet the floor area ratio or a 3,500 sq ft building coverage cap, not both, and the owner chooses which.

• An average density subdivision keeps the same 150 ft width on 0.8035 acres with 25 ft to each side and 60 ft for the pair, and raises the floor area ratio to 0.12.
• An active adult community, a special permit use under § 290-57, is capped at 120 units; a single-story home sits on 0.1148 acres with 10 ft to each side, two storeys and 10% coverage.
• A respite facility for disabled children needs 10 acres, 435,600 sq ft, on 250 ft of width with 30 ft each side; a preexisting building 15 feet from a line, or an accessory 3 feet, is exempt.
• Minimum lot frontage is 100 ft, separate from lot width. The Planning Board may reduce it for a residential lot on a cul-de-sac or a street curving at a radius of a hundred feet or less.
• Only a quarter of land under water, in a village wetland, hundred-year floodplain or open drainage easement, under overhead utility lines or unexcavated over 25% slope counts toward the lot minimum.
• Only three quarters of land in a conservation easement, a piped drainage easement, a sewer easement or an underground utility easement counts toward a minimum lot area.

One-Family Residence - The 20% coverage figure is the maximum impervious surface ratio, counting drives, terraces and every other hard surface along with the buildings. A building must meet the floor area ratio or a 3,250 sq ft building coverage cap, not both, and the owner chooses which.

• An average density subdivision is a second complete row: 0.5739 acres on 125 ft of width, 20 ft to each side with 50 ft for the pair, 35 ft front and rear, and a floor area ratio of 0.15.
• An active adult community, a special permit use under § 290-57, is capped at 120 units; a single-story home sits on 0.1148 acres with 10 ft each side, two storeys and 10% coverage.
• A townhouse in such a community sits on 0.0459 acres with side yards of 0 ft on either side, 10 ft to the rear and 20 ft to the front, a lot depth of 45 feet and 45 percent coverage.
• A respite facility for disabled children needs 10 acres, 435,600 sq ft, on 250 ft of width with 30 ft each side; a preexisting building 15 feet from a line, or an accessory 3 feet, is exempt.
• Minimum lot frontage is 100 ft, separate from lot width. The Planning Board may reduce it for a residential lot on a cul-de-sac or a street curving at a radius of a hundred feet or less.
• Only a quarter of land under water, in a village wetland, hundred-year floodplain or open drainage easement, under overhead utility lines or unexcavated over 25% slope counts toward the lot minimum.

One-Family Residence - The 25% coverage figure is the maximum impervious surface ratio, counting drives, terraces and every other hard surface along with the buildings. A building must meet the floor area ratio or a 3,000 sq ft building coverage cap, not both, and the owner chooses which.

• An average density subdivision is a second complete row: 0.3444 acres on 100 ft of width, 20 ft to each side with 50 ft for the pair. Minimum lot frontage is 90 ft, separate from lot width.
• A respite facility for families of disabled children needs 10 acres, 435,600 square feet, on 250 ft of width and the same street frontage, with 30 ft to each side, by special permit under § 290-55.
• A preexisting building 15 feet or more from a property line, and a preexisting accessory building 3 feet or more from one, need not meet that row's figures.
• No land inside an access easement or right-of-way counts toward a minimum lot area, and the lot area rules bind existing easements as well as proposed ones.
• Only a quarter of land under water, in a village wetland, hundred-year floodplain or open drainage easement, under overhead utility lines or unexcavated over 25% slope counts toward the lot minimum.
• Only three quarters of land in a conservation easement, a piped drainage easement, a sewer easement or an underground utility easement counts toward a minimum lot area.

One- and Two-Family Residence - A two-family house has its own figures, with side yards of 15 ft a side and 40 ft for the pair instead of 20 and 50, in exchange for five thousand more square feet of land.

• A two-family detached house is permitted by right on 0.4591 acres and 125 ft of width and the same street frontage, with 15 ft a side and 40 ft for the pair, and its impervious ratio rises to 30%.
• Independent living for people with disabilities is a special permit use under § 290-56, in this district only: 4 acres on 350 ft of width, 20 ft a side with 60 ft for the pair, one storey and 25 ft.
• A respite facility for families of disabled children needs 10 acres, 435,600 square feet, on 250 ft of width; a preexisting building 15 feet from a line, or an accessory one 3 feet, need not comply.
• A building must meet the floor area ratio or a coverage cap of 2,500 sq ft for a one-family house and 2,750 for a two-family, not both; the 25% shown is the maximum impervious surface ratio.
• Minimum lot frontage is 85 ft, separate from lot width. The Planning Board may reduce it for a residential lot on a cul-de-sac or a street curving at a radius of a hundred feet or less.
• Only a quarter of land under water, in a village wetland, hundred-year floodplain or open drainage easement, under overhead utility lines or unexcavated over 25% slope counts toward the lot minimum.

Laboratory-Office - The 75% coverage figure is the maximum impervious surface ratio, counting drives, terraces and every other hard surface along with the buildings. Minimum lot frontage is 100 ft, a standard separate from the lot width.

• A respite facility for families of disabled children needs 10 acres, 435,600 square feet, on 250 ft of width and the same street frontage, by special permit under § 290-55.
• A preexisting building 15 feet or more from a property line, and a preexisting accessory building 3 feet or more from one, need not meet that row's figures.
• There is no storey limit here, only the 45 ft height.
• No land inside an access easement or right-of-way counts toward a minimum lot area, and the lot area rules bind existing easements as well as proposed ones.
• Only a quarter of land under water, in a village wetland, hundred-year floodplain or open drainage easement, under overhead utility lines or unexcavated over 25% slope counts toward the lot minimum.
• Only three quarters of land in a conservation easement, a piped drainage easement, a sewer easement or an underground utility easement counts toward a minimum lot area.

Neighborhood Commercial - Lot area has a maximum as well as a minimum: at least 2 acres and at most six acres, net of environmental deductions. Parcels may not be assembled afterwards to reach the threshold; the minimum is judged on lots as they existed when the local law was adopted.

• The 35 ft height is for a principal building; an accessory building is held to fifteen.
• Minimum lot frontage is 150 ft, a standard separate from the lot width.
• The 75% coverage figure is the maximum impervious surface ratio, counting drives, terraces and every other hard surface along with the buildings.
• A building must meet the floor area ratio or the building coverage cap, not both; the owner chooses which of the two to be held to on the application.
• No land inside an access easement or right-of-way counts toward a minimum lot area, and the lot area rules bind existing easements as well as proposed ones.
• Only a quarter of land under water, in a village wetland, hundred-year floodplain or open drainage easement, under overhead utility lines or unexcavated over 25% slope counts toward the lot minimum.