What it costs to build an ADU in New Castle, NY

Multifamily Planned Development District - Density is set by land per dwelling unit: at least 4,400 sq ft for an efficiency, 6,600 for one bedroom, 8,800 for two, 11,000 for three, and 13,200 for four bedrooms or a one-family detached dwelling.

• The five acres is the whole development, and lots inside a development subdivided on a Planning Board plan have no minimum.
• Where the lot adjoins a one-family residence district, the side and rear yards must be at least 30 ft or one and one-half times the height of the building, whichever is greater.
• Coverage counts nonwetland area plus 33% of wetland area and excludes parking wholly underground, and wetland area counts at one third toward density.
• The board approving the concept plan may grant an incentive increase above that density.
• Each dwelling unit needs at least 450 sq ft of floor area for an efficiency, 650 for one bedroom, 750 for two, 1,000 for three and 1,200 for four.
• Three- and four-bedroom units must have at least one and one-half baths.

One-Family Residence District - Building coverage, development coverage and floor area are capped in square feet on a sliding scale by lot area. On a lot of 87,120 sq ft or more, buildings may cover 5,739 sq ft plus 2% of the area above 87,120 sq ft.

• Development coverage on such a lot is 13,098 sq ft plus 7% of the area above 87,120 sq ft, counting all buildings and structures, including driveways, parking areas, walks, decks and terraces.
• Floor area, counting half of garage and basement floors, is capped at 7,841 sq ft on a lot of 87,120 to 98,010 sq ft, rising in steps to 10,193 sq ft below 196,020 sq ft.
• A lot holding a single-family affordable AFFH unit needs 75% of the lot area, and one holding a two-family affordable AFFH unit needs the one-family lot area.
• No more than 10% of the minimum lot area may be under water, floodway or wetland.
• A yard equal to the front yard is required along every lot line that abuts a street, and no accessory building, deck, porch or terrace may stand in a required yard.
• A multifamily designed residential development needs a Planning Board special permit and a site at least 100 times the one-family lot minimum, at 10% building and 20% development coverage.

One-Family Residence District - A lot lying in both R-2A and R-1A must meet the most stringent lot area, setbacks, building coverage and development coverage of either (§ 60-330), and R-2A ranks as the more restrictive, so its figures apply.

• On a lot of 87,120 sq ft or more, building coverage is capped at 5,739 sq ft plus 2% of the area above 87,120 sq ft.
• Development coverage on such a lot is 13,098 sq ft plus 7% of the area above 87,120 sq ft, counting all buildings and structures, including driveways, parking areas, walks, decks and terraces.
• Floor area, counting half of garage and basement floors, is capped at 7,841 sq ft on a lot of 87,120 to 98,010 sq ft, rising in steps to 10,193 sq ft below 196,020 sq ft.
• No more than 10% of the minimum lot area may be under water, floodway or wetland.
• A yard equal to the front yard is required along every lot line that abuts a street, and no accessory building, deck, porch or terrace may stand in a required yard.
• A multifamily designed residential development needs a Planning Board special permit and a site at least 100 times the one-family lot minimum, at 10% building and 20% development coverage.

Multifamily Residence District - Chappaqua - Basic density, by right with site plan approval, is set by land per dwelling unit: at least 2,200 sq ft for an efficiency, 3,300 for one bedroom, 4,400 for two, 5,500 for three, and 6,600 for four bedrooms or a one-family detached dwelling.

• A Planning Board special permit may raise that density by up to 100% for incentive features such as affordable, senior, handicapped or rental units, underground parking or recreation facilities.
• A development of five to nine units must include one affordable AFFH unit, and one of 10 or more units at least 10%.
• Every unit must connect to public water and sewer.
• The one acre is the whole development, and lots inside a development subdivided on a Planning Board plan have no minimum.
• Coverage counts nonwetland area plus 33% of wetland area and excludes parking wholly underground, and wetland area counts at one third toward density.

Multifamily Residence District - Millwood - Where the lot adjoins a one-family residence district, the side and rear yards must be at least 25 ft or the height of the building, whichever is greater.

• Density is set by land per dwelling unit, at least 3,300 sq ft for an efficiency, 4,950 for one bedroom and 6,600 for two, by right with site plan approval.
• It is at least 8,250 sq ft for a three-bedroom unit and 9,900 for four bedrooms or a one-family detached dwelling.
• A Planning Board special permit may raise that density by up to 100% for incentive features such as affordable, senior, handicapped or rental units, underground parking or recreation facilities.
• A development of five to nine units must include one affordable AFFH unit, and one of 10 or more units at least 10%.
• Sites are to be served by public or community water and sewer.
• The one acre is the whole development, and lots inside a development subdivided on a Planning Board plan have no minimum.

One-Family Residence District - Where there is no municipal water main within 200 feet of the existing or proposed building, the minimum lot reverts to the R-1A requirement of one acre.

• On a lot of 21,780 to 43,560 sq ft, building coverage is capped at 3,343 sq ft plus 5% of the area above 21,780 sq ft.
• Development coverage on such a lot is 5,475 sq ft plus 15% of the area above 21,780 sq ft, counting all buildings and structures, including driveways, parking areas, walks, decks and terraces.
• Floor area, counting half of garage and basement floors, is capped at 4,792 sq ft on a lot of 21,780 to 24,200 sq ft, rising in steps to 5,770 sq ft at 38,720 sq ft or more.
• No more than 10% of the minimum lot area may be under water, floodway or wetland.
• A yard equal to the front yard is required along every lot line that abuts a street, and no accessory building, deck, porch or terrace may stand in a required yard.
• A multifamily designed residential development needs a Planning Board special permit and a site at least 100 times the one-family lot minimum, at 10% building and 20% development coverage.

One-Family Residence District - A lot lying in both R-1/2A and R-1/4A must meet the most stringent lot area, setbacks and coverage of either (§ 60-330), and R-1/2A is the more restrictive. Where no municipal water main lies within 200 ft of the existing or proposed building, the lot must be at least one acre.

• On a lot of 21,780 to 43,560 sq ft, building coverage is capped at 3,343 sq ft plus 5% of the area above 21,780 sq ft.
• Development coverage on such a lot is 5,475 sq ft plus 15% of the area above 21,780 sq ft, counting all buildings and structures, including driveways, parking areas, walks, decks and terraces.
• Floor area, counting half of garage and basement floors, is capped at 4,792 sq ft on a lot of 21,780 to 24,200 sq ft, rising in steps to 5,770 sq ft at 38,720 sq ft or more.
• No more than 10% of the minimum lot area may be under water, floodway or wetland.
• A yard equal to the front yard is required along every lot line that abuts a street, and no accessory building, deck, porch or terrace may stand in a required yard.
• A multifamily designed residential development needs a Planning Board special permit and a site at least 100 times the one-family lot minimum, at 10% building and 20% development coverage.

One-Family Residence District - Building coverage, development coverage and floor area are capped in square feet on a sliding scale by lot area. On a lot of 43,560 to 87,120 sq ft, buildings may cover 4,432 sq ft plus 3% of the area above 43,560 sq ft.

• Development coverage on such a lot is 8,742 sq ft plus 10% of the area above 43,560 sq ft, counting all buildings and structures, including driveways, parking areas, walks, decks and terraces.
• Floor area, counting half of garage and basement floors, is capped at 6,098 sq ft on a lot of 43,560 to 48,400 sq ft, rising in steps to 7,320 sq ft at 77,440 sq ft or more.
• A lot holding a single-family affordable AFFH unit needs 75% of the lot area, and one holding a two-family affordable AFFH unit needs the one-family lot area.
• No more than 10% of the minimum lot area may be under water, floodway or wetland.
• A yard equal to the front yard is required along every lot line that abuts a street, and no accessory building, deck, porch or terrace may stand in a required yard.
• A multifamily designed residential development needs a Planning Board special permit and a site at least 100 times the one-family lot minimum, at 10% building and 20% development coverage.

One-Family Residence District - A lot lying in both R-1A and R-1/2A must meet the most stringent lot area, setbacks, building coverage and development coverage of either (§ 60-330), and R-1A ranks as the more restrictive, so its figures apply.

• On a lot of 43,560 to 87,120 sq ft, building coverage is capped at 4,432 sq ft plus 3% of the area above 43,560 sq ft.
• Development coverage on such a lot is 8,742 sq ft plus 10% of the area above 43,560 sq ft, counting all buildings and structures, including driveways, parking areas, walks, decks and terraces.
• Floor area, counting half of garage and basement floors, is capped at 6,098 sq ft on a lot of 43,560 to 48,400 sq ft, rising in steps to 7,320 sq ft at 77,440 sq ft or more.
• No more than 10% of the minimum lot area may be under water, floodway or wetland.
• A yard equal to the front yard is required along every lot line that abuts a street, and no accessory building, deck, porch or terrace may stand in a required yard.
• A multifamily designed residential development needs a Planning Board special permit and a site at least 100 times the one-family lot minimum, at 10% building and 20% development coverage.

One-Family Residence District - A lot lying in both R-1A and R-1/4A must meet the most stringent lot area, setbacks, building coverage and development coverage of either (§ 60-330), and R-1A ranks as the more restrictive, so its figures apply.

• On a lot of 43,560 to 87,120 sq ft, building coverage is capped at 4,432 sq ft plus 3% of the area above 43,560 sq ft.
• Development coverage on such a lot is 8,742 sq ft plus 10% of the area above 43,560 sq ft, counting all buildings and structures, including driveways, parking areas, walks, decks and terraces.
• Floor area, counting half of garage and basement floors, is capped at 6,098 sq ft on a lot of 43,560 to 48,400 sq ft, rising in steps to 7,320 sq ft at 77,440 sq ft or more.
• No more than 10% of the minimum lot area may be under water, floodway or wetland.
• A yard equal to the front yard is required along every lot line that abuts a street, and no accessory building, deck, porch or terrace may stand in a required yard.
• A multifamily designed residential development needs a Planning Board special permit and a site at least 100 times the one-family lot minimum, at 10% building and 20% development coverage.

One-Family Residence District - Where there is no municipal water main within 200 feet of the existing or proposed building, the minimum lot reverts to the R-1A requirement of one acre.

• On a lot of 11,250 to 21,780 sq ft, building coverage is capped at 2,500 sq ft plus 8% of the area above 11,250 sq ft, and at 22% on a smaller lot.
• Development coverage on such a lot is 4,000 sq ft plus 14% of the area above 11,250 sq ft, and 35% on a smaller lot.
• Floor area, counting half of garage and basement floors, is capped at 3,158 sq ft on a lot of 10,890 to 12,100 sq ft, rising in steps to 4,100 sq ft at 18,150 sq ft or more.
• No more than 10% of the minimum lot area may be under water, floodway or wetland.
• A yard equal to the front yard is required along every lot line that abuts a street, and no accessory building, deck, porch or terrace may stand in a required yard.
• A multifamily designed residential development needs a Planning Board special permit and a site at least 100 times the one-family lot minimum, at 10% building and 20% development coverage.

Research and Office Business - The front yard may be reduced to 50 ft for a one-story gatehouse or security office, which must still sit at least 150 ft from a residence district.

• On a development plan the Planning Board may cut that 150 ft to no less than 60 ft for equivalent screening, or where the lot abuts a utility or railroad right-of-way or a limited-access highway.
• The side and rear yards may be reduced to 100 ft where the lot adjoins a lot in a business or industrial district, and to 50 ft for a one-story gatehouse or security office.
• Parking and loading areas must be at least 100 ft from the front, side and rear lot lines.
• A driveway must be at least 100 ft from a side or rear lot line abutting a residence district unless the Planning Board approves less.
• The bulk and dimensional regulations do not apply to a property on which an existing building is adaptively reused for residential use.
• A buffer screening strip at least 10 ft wide is required along any lot line abutting a residence district (§ 60-420D(2)).

Designed Business - The front yard rises to 75 ft where off-street parking sits in it. Any side yard that is provided must be at least 6 ft, and at least 75 ft if parking sits in it.

• Multifamily dwellings follow the standards of the MFR-C district, including its land per dwelling unit density ladder, at 20% building and 35% development coverage.
• A side yard must be at least 10 ft where it adjoins a street and at least 25 ft where it is used as access to off-street parking.
• The rear yard must be at least 25 ft where it is used as access to off-street parking and at least 50 ft where the lot adjoins a residence district.
• No rear yard is required where the lot abuts the side line of a business lot.
• Parking and loading areas must be at least 15 ft from the lot lines, or less between adjoining business parking areas with Planning Board approval.
• A buffer screening strip at least 10 ft wide is required along any lot line abutting a residence district (§ 60-420D(2)).

Retail Business - The front yard rises to 75 ft where off-street parking sits in it. No side yard is required where the lot abuts a business lot, but any side yard that is provided must be at least 6 ft.

• Multifamily dwellings follow the standards of the MFR-C district, including its land per dwelling unit density ladder, at 20% building and 35% development coverage.
• A side yard must be at least 10 ft where it adjoins a street and at least 25 ft where it is used as access to off-street parking.
• A building must be at least 2 stories and 30 ft high unless its use is exempt from that rule, and any story above the street level floor must be fitted for later residential use (§ 60-410C).
• Apartments are allowed above or below the street level floor of a nonresidential building (§ 60-410H(6)).
• Workforce housing by Town Board special permit, on lots within 1500 ft of the Chappaqua railroad station, uses the B-R lot and bulk figures (§ 60-430O(15)).
• A buffer screening strip at least 10 ft wide is required along any lot line abutting a residence district (§ 60-420D(2)).

Retail Business and Parking - Buildings must sit within the building areas shown on the adopted B-RP Zoning District Map, and floor area may not exceed 2.0 times the designated building area.

• By North Greeley Net Zero Carbon special permit a mixed-use building may reach 50 ft and four stories, free of that floor area limit, though the Town Board may set a lower height.
• That permit needs a lot of at least 33,000 sq ft on the west side of North Greeley Avenue, not a corner lot, with ground floor retail or commercial use.
• A building must be at least 2 stories and 30 ft high unless its use is exempt from that rule, and any story above the street level floor must be fitted for later residential use (§ 60-410C).
• No side or rear yard is required where the lot abuts a business lot; one that is provided must be at least 6 ft, 10 ft where it adjoins a street and 25 ft where used for access to off-street parking.
• Under that permit, land per dwelling unit is at least 375 sq ft for an efficiency, 500 for one bedroom and 750 for two.
• A buffer screening strip at least 10 ft wide is required along any lot line abutting a residence district (§ 60-420D(2)).

General Industrial - The side yard and the rear yard must each be at least 25 ft along any street.

• The minimum average lot width is 60 ft.
• Workforce housing by Town Board special permit, on lots within 500 ft of the Chappaqua railroad station, uses the B-R lot and bulk figures (§ 60-430O(15)).
• Parking and loading areas need no setback.
• A buffer screening strip at least 10 ft wide is required along any lot line abutting a residence district (§ 60-420D(2)).

Planned Industrial - The yard from a residence district must be at least 150 ft, which the Planning Board may cut on a development plan to no less than 60 ft for equivalent screening, or where the lot abuts a utility or railroad right-of-way or a limited-access highway.

• The lot need only be at least 7.5 acres where it abuts a railroad or limited-access highway right-of-way.
• The 100 ft yard applies to the front, side and rear lot lines alike.
• Parking and loading areas must be at least 25 ft from the front, side and rear lot lines, and a driveway at least 50 ft from a side or rear lot line abutting a residence district.
• A buffer screening strip at least 10 ft wide is required along any lot line abutting a residence district (§ 60-420D(2)).