What it costs to build an ADU in Yorktown, NY

One-Family Residential District, One-Family Residential District - Under the large lot clustering article the lot minimum drops to 100,000 sq ft (§ 300-221B), the R1-200 setbacks still apply (§ 300-221C), and the site does not need public water or sewer (§ 300-220B).

• At least 40% of a clustered site must stay open space (§ 300-222).
• On a street with a right-of-way of less than 50 ft, the front yard is measured from the roadway's center line and 25 ft is added.
• On a corner lot the side yard on the side street must equal the required front yard on that street (§ 300-13G).
• Where a block shows a pronounced uniform alignment within 250 ft, the front yard conforms to that alignment instead and is capped at 50 ft (§ 300-13H).
• An accessory building in the rear yard must be at least 10 ft from each side line and 10 ft from the rear line, and must sit behind the front yard setback line (§ 300-14B).
• No more than 10% of the minimum lot area may be met with land under water or subject to periodic flooding, and land under water open to others does not count at all (§ 300-11F).

One-Family Residential District - In a cluster subdivision the lot minimum drops to 10,000 sq ft (§ 300-213B), but only on a site with public water and public sewer (§ 300-212B) and at least 50 ft of frontage on a public street (§ 300-212C), and the yards are then set by the approving board.

• On a street with a right-of-way of less than 50 ft, the front yard is measured from the roadway's center line and 25 ft is added.
• On a corner lot the side yard on the side street must equal the required front yard on that street (§ 300-13G).
• Where a block shows a pronounced uniform alignment within 250 ft, the front yard conforms to that alignment instead and is capped at 50 ft (§ 300-13H).
• An accessory building in the rear yard must be at least 10 ft from each side line and 10 ft from the rear line, and must sit behind the front yard setback line (§ 300-14B).
• The 1,200 sq ft of usable floor area excludes open porches, breezeways, basements and unfinished attic space (§ 300-15).
• No more than 10% of the minimum lot area may be met with land under water or subject to periodic flooding, and land under water open to others does not count at all (§ 300-11F).

One-Family Residential District - In a cluster subdivision the lot minimum drops to 10,000 sq ft (§ 300-213B), but only on a site with public water and public sewer (§ 300-212B) and at least 50 ft of frontage on a public street (§ 300-212C), and the yards are then set by the approving board.

• On a street with a right-of-way of less than 50 ft, the front yard is measured from the roadway's center line and 25 ft is added.
• On a corner lot the side yard on the side street must equal the required front yard on that street (§ 300-13G).
• Where a block shows a pronounced uniform alignment within 250 ft, the front yard conforms to that alignment instead and is capped at 50 ft (§ 300-13H).
• An accessory building wholly or partly in the rear yard with a footprint 50% or more of the main building must be at least 20 ft from the side and rear lines, rather than 10 ft.
• No accessory building may exceed 80% of the main building's footprint (§ 300-14D).
• The 1,000 sq ft of usable floor area excludes open porches, breezeways, basements and unfinished attic space (§ 300-15).

One-Family Residential District - In a cluster subdivision the lot minimum drops to 10,000 sq ft (§ 300-213B), but only on a site with public water and public sewer (§ 300-212B) and at least 50 ft of frontage on a public street (§ 300-212C), and the yards are then set by the approving board.

• On a street with a right-of-way of less than 50 ft, the front yard is measured from the roadway's center line and 25 ft is added.
• On a corner lot the side yard on the side street must equal the required front yard on that street (§ 300-13G).
• Where a block shows a pronounced uniform alignment within 250 ft, the front yard conforms to that alignment instead and is capped at 50 ft (§ 300-13H).
• A large accessory building wholly or partly in the rear yard must be at least 20 ft from the side and rear lines, rather than 10 ft.
• No accessory building may exceed 80% of the main building's footprint (§ 300-14D).
• The 800 sq ft of usable floor area excludes open porches, breezeways, basements and unfinished attic space (§ 300-15).

One-Family Residential District - The lot minimum here is 20,000 sq ft, the same as R1-20, and not the 10,000 sq ft the name suggests. The 10,000 sq ft is reachable only as a cluster subdivision (§ 300-213B), on a site with public water and public sewer (§ 300-212B).

• In a cluster the yards are set by the approving board, and the site needs at least 50 ft of frontage on a public street (§ 300-213C).
• On a street with a right-of-way of less than 50 ft, the front yard is measured from the roadway's center line and 25 ft is added.
• On a corner lot the side yard on the side street must equal the required front yard on that street (§ 300-13G).
• Where a block shows a pronounced uniform alignment within 250 ft, the front yard conforms to that alignment instead and is capped at 50 ft (§ 300-13H).
• An accessory building in the rear yard owes 10 ft from each side line and 10 ft from the rear line, and a large one owes 20 ft.
• The 800 sq ft of usable floor area excludes open porches, breezeways, basements and unfinished attic space (§ 300-15).

Two-Family Residential District - The lot minimum splits by use: 10,000 sq ft for a one-family dwelling and 20,000 sq ft for a two-family dwelling.

• On a street with a right-of-way of less than 50 ft, the front yard is measured from the roadway's center line and 25 ft is added.
• On a corner lot the side yard on the side street must equal the required front yard on that street (§ 300-13G).
• Where a block shows a pronounced uniform alignment within 250 ft, the front yard conforms to that alignment instead and is capped at 50 ft (§ 300-13H).
• An accessory building in the rear yard owes 10 ft from each side line and 10 ft from the rear line, or 20 ft if it is a large one, and may not exceed 80% of the main building's footprint.
• No more than 10% of the minimum lot area may be met with land under water or subject to periodic flooding, and land under water open to others does not count at all (§ 300-11F).

Multifamily Residential District - The 3,630 sq ft is land per dwelling unit rather than a minimum lot size, and every multifamily or apartment development must be built to a site plan approved under §§ 300-82 to 300-85.

• The 0.20 floor area ratio goes with a ceiling of 12 units per acre; it is 0.215 at 10 units per acre and 0.23 at 9.
• Where public sewers are not available the floor area ratio is halved.
• Both the floor area ratio and the lot area are worked out on net area, with wetlands and controlled areas taken off the gross site.
• On a Town Board resolution the Planning Board may approve row houses and townhouses of not more than three storeys at the same density (§ 300-22B(1)).
• Off-street parking is one and one-half spaces per dwelling unit.
• No more than 10% of the minimum lot area may be met with land under water or subject to periodic flooding, and land under water open to others does not count at all (§ 300-11F).

Residential Medium-Density (within CBD) District - No lot area, lot width or lot depth is published for R-3A, and its bulk comes from the urban renewal article, which reaches only land being redeveloped as part of an approved urban renewal project in the CBD (§ 300-25A).

• Buildings must stand back 30 ft from public rights-of-way, and attached buildings 30 ft from side and rear property lines.
• A semidetached or detached building needs 20 ft from the side and rear property lines (§ 300-25A(3)).
• Where a site abuts the open-space strip reserved for the proposed state highway, buildings must stand back 30 ft from its limits.
• Density may not exceed 20 dwelling units per acre.
• The 0.35 floor area ratio is worked out on net area after wetlands and controlled areas are taken off, and is halved where public sewers are unavailable.

Age-Oriented Community - The district is built to a plan of development approved by the Planning Board under §§ 300-123 to 300-151, and density may not exceed 12 units per acre.

• The 15 acres is a minimum site area rather than a buildable lot, and the site also needs 300 ft of total frontage on a state, county or Town highway (§ 300-126A).
• The 10,000 sq ft per dwelling unit is the one-family figure, averaged over the whole site; a two-family dwelling is allotted 14,000 sq ft (§ 300-125A).
• Row houses and multiple dwellings are allotted by room count: 2,500 sq ft for a one-room unit, 3,500 for two rooms, 5,500 for three, 7,000 for four and 10,000 for five.
• Where the whole development holds nothing larger than a three-room, two-bedroom unit the allotment is 3,630 sq ft.
• Minimum usable floor area is 500 sq ft in a row house or multiple dwelling, against 750 sq ft otherwise.
• The floor area ratio is worked out on net area with wetlands and controlled areas taken off, and is halved where public sewers are unavailable.

Senior Citizens District - The 2,200 sq ft is land per living unit rather than a lot minimum, and the 5 acres is a minimum site area. The district is reachable only by special permit of the Planning Board after a public hearing (§ 300-152).

• The site needs a common water supply and a common sanitary sewer, and must lie within 1,500 ft of commercially zoned land in Yorktown Heights, Jefferson Valley, Crompond, Shrub Oak or Lake Mohegan.
• The 2,200 sq ft allotment covers living units up to three rooms, or two bedrooms; anything over two bedrooms or four rooms is allotted 10,000 sq ft.
• Height rises from 45 ft to 55 ft on a site larger than 25 acres.
• The rear yard is the same as the side yards, and an accessory building in the rear yard must be at least 25 ft from either side lot line.
• Minimum usable floor area is 350 sq ft for a studio, 450 for a one-bedroom and 550 for two bedrooms or more.
• Every multifamily or apartment development must also be built to a site plan approved under §§ 300-82 to 300-85.

Age-Oriented Geriatric Community - The 150 ft setback applies only along property lines abutting a residential district; along any other district boundary, the setback is the minimum setback of the district it abuts.

• The 25 acres applies to a combination of two or more facilities (§ 300-161A).
• The 150 ft covers accessory buildings as well as main structures.
• Height is capped at three floors as well as 42 ft, and no more than 300 beds on one site.
• Density is published per facility type and mostly in beds, so the figure turns on the use; congregate housing and staff housing are 10 units per acre (§ 300-161B).
• A staff building holds not more than 10 units, and occupancy is limited to patients, residents, staff and their families (§ 300-161F).
• Development is approved by the Planning Board on a site plan under §§ 300-164 to 300-166.

Commercial Regional Center District - CRC is built to a plan of development approved by the Town Board under § 300-86, on a site of at least 35 acres with at least 500 ft of frontage.

• No main building may stand closer than 50 ft to the street it fronts (§ 300-88A).
• Where the site plan proposes a covered mall and 80% of the development relates to it, coverage rises to 30% with the floor area ratio unchanged (§ 300-88C).
• The site must be logically related to a regionally significant highway (§ 300-87).
• The article that governs this district publishes no height limit and no side or rear yard, so those are not established.
• Separate structures under 500 sq ft are not permitted.
• Uses are approved by the Town Board after public notice and hearing.

Commercial Shopping Center District - The 15 ft front yard applies only where there is no parking in the front yard; with front-yard parking it must be at least 75 ft. Where the lot adjoins an R District, the rear yard must be at least 75 ft and any side yard provided at least 50 ft.

• No side yard is required, but one that is provided must be at least 10 ft, or at least 17 ft if used for one-way vehicular access and at least 25 ft for two-way.
• An accessory building needs a front yard of at least 50 ft.
• An accessory building owes 10 ft at the rear, or 50 ft against an R District, and accessory buildings are capped at 20 ft in height.
• No development is permitted except in accordance with a plan of development approved by the Planning Board, so the figures shown are not available by right.

Commercial Hamlet Center District - The 15 ft front yard applies only where there is no parking in the front yard; with front-yard parking it must be at least 75 ft. No side yard is required, but one that is provided must be at least 50 ft where the lot adjoins an R District.

• Elsewhere a side yard that is provided must be at least 10 ft, or at least 17 ft if used for one-way vehicular access and at least 25 ft for two-way.
• An accessory building needs a front yard of at least 50 ft, and accessory buildings are capped at 20 ft in height.
• Lot area and lot depth are printed as none, which is the schedule's own wording rather than a figure left out.
• A parking plan must be approved under §§ 300-179 to 300-182 and §§ 300-183 to 300-186, and separate structures under 500 sq ft are not permitted.

Commercial Hamlet Center District - The code sets no yard, height, coverage or lot minimum for C-2R: it has no column in the dimensional schedule and no section of its own, and C-2's figures do not carry across. Confirm the standards with the Town Planning Department before relying on any of them.

• A C-2R parcel in Yorktown Heights may also sit inside the planned design district overlay of § 300-255, where the Planning Board can vary bulk outright.
• Residential apartments are confined to the floors above a first-floor use and limited to two bedrooms and 1,000 sq ft per unit (§ 300-21C(10)).

Commercial Limited District - The 30 ft front yard applies only where there is no parking in the front yard; with front-yard parking it must be at least 75 ft. No side yard is required, but one that is provided must be at least 50 ft where the lot adjoins an R District.

• Elsewhere a side yard that is provided must be at least 10 ft, or at least 17 ft if used for one-way vehicular access and at least 25 ft for two-way.
• An accessory building needs a front yard of at least 50 ft, and accessory buildings are capped at 20 ft in height.
• Lot depth is printed as none, which is the schedule's own wording rather than a figure left out.
• A parking plan must be approved under §§ 300-179 to 300-182 and §§ 300-183 to 300-186, and separate structures under 500 sq ft are not permitted.

Commercial General District - No side yard is required, but one that is provided must be at least 10 ft, at least 17 ft if used for one-way vehicular access, at least 25 ft for two-way, and at least 50 ft where the lot adjoins an R District.

• The 15 ft front yard is flat, with no separate figure for a lot that puts parking in the front yard, and an accessory building needs 15 ft.
• Accessory buildings are capped at 20 ft in height.
• Lot area is printed as none, which is the schedule's own wording rather than a figure left out.
• A parking plan must be approved under §§ 300-179 to 300-182 and §§ 300-183 to 300-186, and separate structures under 500 sq ft are not permitted.

Commercial Recreation District - Confirm the height with the Town before relying on it: the schedule's height rows for this district can also be read as a 20 ft main building rather than 35 ft.

• The 25 ft front yard applies only where there is no parking in the front yard; with front-yard parking it must be at least 75 ft.
• An accessory building needs a front yard of at least 25 ft, and accessory buildings are capped at 20 ft in height.
• The schedule publishes no side yard figure for this district, so no side yard is established.
• Lot depth is printed as none, which is the schedule's own wording rather than a figure left out.
• Separate structures under 500 sq ft are not permitted, and development must conform to applicable Westchester County and New York State health regulations.

Country Commercial District - Dwelling units are controlled by land rather than by the floor area ratio: one unit per 15,000 sq ft for apartments above a first-floor commercial use, and one per 7,500 sq ft only on a Planning Board special permit for multifamily (§ 300-238.1).

• The side yard rises from 15 ft to 20 ft where the lot is adjacent to a residential district (§ 300-241F(3)).
• That multifamily special permit resets the lot minimum to 20,000 sq ft and lot width and depth to 100 ft each, and forbids mixed use.
• Minimum lot area is otherwise none, which is the article's own wording rather than a figure left out (§ 300-241A).
• The 0.20 floor area ratio governs commercial or mixed-use structures.
• The 30% coverage counts principal and accessory buildings together.
• No building may exceed 100 ft in length, and every 40 ft of facade facing a public street must step back or forward (§ 300-241E).

Research Laboratory and Office District - Lots must be at least 20 acres with at least 500 ft of frontage. The side and rear yards drop to 100 ft between two adjoining lots that both carry a laboratory or office building.

• A one-story gatehouse, bus shelter or security office may sit as close as 25 ft to the front street (§ 300-107A).

Office District - The 15 ft front yard applies only where there is no parking in the front yard; with front-yard parking it must be at least 75 ft. No side yard is required, but one that is provided must be at least 50 ft where the lot adjoins an R District.

• Elsewhere a side yard that is provided must be at least 10 ft, or at least 17 ft if used for one-way vehicular access and at least 25 ft for two-way.
• An accessory building needs a front yard of at least 50 ft, and accessory buildings are capped at 20 ft in height.
• Street frontage is 75 ft under § 300-11G(1)(c) even though lot width at the main building line is 25 ft; frontage and width are separate measures here.
• Lot area and lot depth are printed as none, which is the schedule's own wording rather than a figure left out.
• A parking plan must be approved under §§ 300-179 to 300-182 and §§ 300-183 to 300-186, and separate structures under 500 sq ft are not permitted.

Light Industrial Park District - Against a residence district, the setback from the boundary must be at least 200 ft (§ 300-97).

• A one-story gatehouse, bus shelter or security office needs a front setback of at least 30 ft rather than 75 ft.

Planned Light Industrial District - The figures shown for this district are incomplete: its building coverage and floor area ratio are not established, because the two schedule columns that could apply to it disagree. Confirm any of them with the Town Planning Department.

• Street frontage is a flat 75 ft (§ 300-11G(1)(c)), rather than being set by an approved plan of development as it is in the neighbouring light industrial district.

Planned Interchange District - The 100 ft setback applies to every building and structure other than sign posts and directional signs, and it is one figure measured from any property line rather than three separate yards (§ 300-154D).

• Paved areas must be at least 50 ft from a property line and at least 10 ft from any building (§ 300-154D).
• The site must be at least 10 acres with at least 100 ft of frontage on a roadway (§ 300-154A(1)).
• The 15% coverage and the 0.4 floor area ratio are worked out on the gross acreage of the whole parcel.
• A phased condominium office project may subdivide the site into lots smaller than 10 acres once the Town Board has conceptually approved a plan of development for the whole site (§ 300-154A(2)).
• Those smaller lots escape the frontage, coverage, floor area ratio and setback rules, except where a lot adjoins a Town road or a property adjacent to the interchange site.
• Development is approved by the Town Board under Art. VIII.

Transitional Zone - Land is placed in T one parcel at a time by Town Board rezoning, and the Town Board sets the uses, density, setbacks, area and bulk requirements for each property individually, on the Planning Board's recommendation.

• Intensity may not exceed the less restrictive abutting district, or the most restrictive nonresidential district that could otherwise apply where the site buffers a major traffic route.
• The conditions set for a parcel run with the land for as long as the designation lasts.
• A targeted property lies between two distinctly different zoning districts, or buffers residential uses from a major traffic route, mostly along the Route 6 corridor (§ 300-169).