Can you build an ADU in Guilderland, NY?

Agricultural - A cluster subdivision, which the Planning Board must permit rather than it being available by right, cuts the lot minimum from two acres to 15,000 sq ft (0.34 acre), the building line width from 200 ft to 80 ft and the side yard from 50 ft to 10 ft.

• A cluster must keep at least 50% of the parent parcel and 50% of its buildable land in permanent conservation area, half of that contiguous, with at least one preserved parcel of 3 acres or more.
• Town-wide setbacks can exceed every figure here: 100 ft from the top of the bank of any watercourse, 250 ft from a watercourse feeding the Watervliet reservoir and 500 ft from its high-water mark.
• A further rule bars any structure between the top of a bank and a line struck at 12 degrees from the toe of the slope, with 30 ft more beyond that line.
• Barns, silos, water towers and other farm structures on farms are exempt from the height limit if they stand at least 100 ft from any property line.
• On Route 20 west of Route 155, on Route 155, Route 146 and Rapp Road, the setback and the lot area are measured from the future right-of-way line where one has been established.
• The 200 ft width is measured at the building line, not at the street.

Business Non-Retail Professional - Where a lot adjoins any residential district, the side and rear yards both become 40 ft, against the 10 ft side and 35 ft rear that otherwise apply.

• Nothing may stand within 100 ft of the top of the bank of any watercourse or body of water, within 250 ft of the bank of a watercourse feeding the Watervliet reservoir, or 500 ft of the reservoir.
• No structure may stand between the top of a bank and a line struck at 12 degrees from the toe of the slope, with a further 30 ft setback beyond that line.
• On Route 20 west of Route 155, on Route 155, Route 146 and Rapp Road, both the setback and the lot area are measured from the future right-of-way line wherever one has been established.
• The width figure is the width the lot must hold at the building line, not at the street.
• Height is measured from finished grade to a point midway between the highest and lowest points of the roof rather than to the ridge.
• A corner lot takes a full front yard along each road frontage.

Country Hamlet - The code sets no dimensional standards for this district: the applicant proposes them in the development plan, and the planning board may waive any dimensional requirement of the chapter. The density shown is per acre of buildable land, not gross acreage.

• A Country Hamlet is created by a town board rezoning at the applicant's request, only on land already in RA3 or RA5, and must be at least 160 acres unless it adjoins an existing hamlet or village.
• At least 60% of the property must be open space containing at least half the gross buildable area.
• Density bonuses run to 25% for conserving 75% of the acreage, protecting historic resources, off-site sidewalk linkages or other amenities.
• A bonus of up to 40% is available where the applicant extends public water or restricts a quarter of the units to senior housing.
• Commercial may be substituted for housing at 1,000 sq ft per allowed dwelling unit, capped at 40% of the allowed density and 25,000 sq ft for any single structure.
• Multi-family may be no more than 20% of the units.

General Business - Where a lot adjoins a residential district, the side and rear yards both become 75 ft, against the 15 ft shown for each; where it adjoins the LB or BNRP district, the side becomes 25 ft and the rear 50 ft.

• Nothing may stand within 100 ft of the top of the bank of any watercourse or body of water, within 250 ft of the bank of a watercourse feeding the Watervliet reservoir, or 500 ft of the reservoir.
• No structure may stand between the top of a bank and a line struck at 12 degrees from the toe of the slope, with a further 30 ft setback beyond that line.
• On Route 20 west of Route 155, on Route 155, Route 146 and Rapp Road, both the setback and the lot area are measured from the future right-of-way line wherever one has been established.
• The width figure is the width the lot must hold at the building line, not at the street.
• Height is measured from finished grade to a point midway between the highest and lowest points of the roof rather than to the ridge.
• A corner lot takes a full front yard along each road frontage.

Industrial - Where an industrial lot adjoins a residential district, the side and rear yards both become 100 ft, against the 25 ft that otherwise applies to each.

• Nothing may stand within 100 ft of the top of the bank of any watercourse or body of water, within 250 ft of the bank of a watercourse feeding the Watervliet reservoir, or 500 ft of the reservoir.
• No structure may stand between the top of a bank and a line struck at 12 degrees from the toe of the slope, with a further 30 ft setback beyond that line.
• On Route 20 west of Route 155, on Route 155, Route 146 and Rapp Road, both the setback and the lot area are measured from the future right-of-way line wherever one has been established.
• The width figure is the width the lot must hold at the building line, not at the street.
• Height is measured to a point midway between the highest and lowest points of the roof.
• A corner lot takes a full front yard along each road frontage.

Local Business - Where a lot adjoins any residential district, the side and rear yards both become 40 ft, against the 15 ft that otherwise applies to each.

• Nothing may stand within 100 ft of the top of the bank of any watercourse or body of water, within 250 ft of the bank of a watercourse feeding the Watervliet reservoir, or 500 ft of the reservoir.
• No structure may stand between the top of a bank and a line struck at 12 degrees from the toe of the slope, with a further 30 ft setback beyond that line.
• On Route 20 west of Route 155, on Route 155, Route 146 and Rapp Road, both the setback and the lot area are measured from the future right-of-way line wherever one has been established.
• The width figure is the width the lot must hold at the building line, not at the street.
• Height is measured from finished grade to a point midway between the highest and lowest points of the roof rather than to the ridge.
• A corner lot takes a full front yard along each road frontage.

Multiple Residence - Lot area steps with the unit count: 10,000 sq ft for one family, 11,250 for two, 15,000 for three and 18,750 for four. Above four families the governing limit is the density, 12 dwelling units per acre of buildable land.

• A two-family needs 11,250 sq ft, 0.26 acre, against a one-family's 10,000 sq ft.
• Where the lot adjoins a single-family residential district both the side and the rear yard become 100 ft, against the 15 ft and 30 ft otherwise.
• Every use in this district is reached by site plan approval or a special use permit rather than by right.
• Minimum apartment floor area is set by bedroom count: 500 sq ft for a studio, 600 for one bedroom, 800 for two and 950 for three.
• Height is 2 1/2 storeys or 35 ft, whichever binds first, measured to a point midway between the highest and lowest points of the roof rather than to the ridge.

Open Space - The code sets no lot area, width, setback, height or coverage for this district. It marks land already permanently protected: open, natural and forested areas, and land conveyed to the town or reserved as a condition of a subdivision, site plan or special use permit approval.

• The only uses are agriculture and farming, a public park, passive recreation, and a wildlife or historic, scenic or scientific preserve.
• Even those uses may be barred by the condition of the approval that created the parcel.
• Nothing may stand within 100 ft of the top of the bank of any watercourse or body of water, within 250 ft of the bank of a watercourse feeding the Watervliet reservoir, or 500 ft of the reservoir.
• No structure may stand between the top of a bank and a line struck at 12 degrees from the toe of the slope, with a further 30 ft setback beyond that line.

Planned Unit Development - A planned unit development carries no dimensions as a district. It is created by a town board rezoning at the applicant's request, and the figures for a particular development are in its own approving resolution and site plan.

• The front setback comes from the special highway setback rules in § 280-31.
• The side and rear yards are set by the planning board through site plan approval, or specified by the town board and written onto the plat.
• Nothing may stand within 100 ft of the top of the bank of any watercourse or body of water, within 250 ft of the bank of a watercourse feeding the Watervliet reservoir, or 500 ft of the reservoir.
• No structure may stand between the top of a bank and a line struck at 12 degrees from the toe of the slope, with a further 30 ft setback beyond that line.
• A planned unit development must have access to municipal water and wastewater and direct vehicular access to a county or state highway.

Single-Family Residential District - 10 - A cluster subdivision cuts the lot minimum from 10,000 sq ft to 8,000 (0.18 acre) and the side yard from 12.5 ft to 10 ft, but it deepens the rear yard from 30 ft to 50 ft, and the Planning Board must permit it rather than it being available by right.

• A cluster must keep at least 50% of the parent parcel and 50% of its buildable land in permanent conservation area, with at least one preserved parcel of 3 acres or more.
• Town-wide setbacks can exceed every figure here: 100 ft from the top of the bank of any watercourse, 250 ft from a watercourse feeding the Watervliet reservoir and 500 ft from its high-water mark.
• A further rule bars any structure between the top of a bank and a line struck at 12 degrees from the toe of the slope, with 30 ft more beyond that line.
• The 80 ft width is measured at the building line, not at the street.
• On Route 20 west of Route 155, on Route 155, Route 146 and Rapp Road, the setback and the lot area are measured from the future right-of-way line where one has been established.
• An accessory structure belongs in the rear yard, 5 ft from a lot line if minor, 10 ft if major and 15 ft if over 1,000 sq ft, and is capped at 15 ft tall.

Single-Family Residential District - 15 - A cluster subdivision cuts the lot minimum from 15,000 sq ft to 10,000 (0.23 acre) and the building line width from 100 ft to 80 ft, but it deepens the rear yard from 35 ft to 50 ft, and the Planning Board must permit it rather than it being available by right.

• A cluster must keep at least 50% of the parent parcel and 50% of its buildable land in permanent conservation area, with at least one preserved parcel of 3 acres or more.
• Town-wide setbacks can exceed every figure here: 100 ft from the top of the bank of any watercourse, 250 ft from a watercourse feeding the Watervliet reservoir and 500 ft from its high-water mark.
• A further rule bars any structure between the top of a bank and a line struck at 12 degrees from the toe of the slope, with 30 ft more beyond that line.
• The 100 ft width is measured at the building line, not at the street.
• On Route 20 west of Route 155, on Route 155, Route 146 and Rapp Road, the setback and the lot area are measured from the future right-of-way line where one has been established.
• An accessory structure belongs in the rear yard, 5 ft from a lot line if minor, 10 ft if major and 15 ft if over 1,000 sq ft, and is capped at 15 ft tall.

Single-Family Residential District - 20 - A cluster subdivision, which the Planning Board must permit rather than it being available by right, cuts the lot minimum from 20,000 sq ft to 15,000 (0.34 acre), the width from 125 ft to 80 ft, the front yard from 35 ft to 30 ft and the side yard from 20 ft to 10 ft.

• A cluster must keep at least 50% of the parent parcel and 50% of its buildable land in permanent conservation area, with at least one preserved parcel of 3 acres or more.
• Town-wide setbacks can exceed every figure here: 100 ft from the top of the bank of any watercourse, 250 ft from a watercourse feeding the Watervliet reservoir and 500 ft from its high-water mark.
• A further rule bars any structure between the top of a bank and a line struck at 12 degrees from the toe of the slope, with 30 ft more beyond that line.
• The 125 ft width is measured at the building line, not at the street.
• On Route 20 west of Route 155, on Route 155, Route 146 and Rapp Road, the setback and the lot area are measured from the future right-of-way line where one has been established.
• An accessory structure belongs in the rear yard, 5 ft from a lot line if minor, 10 ft if major and 15 ft if over 1,000 sq ft, and is capped at 15 ft tall.

Single-Family Residential District - 40 - A cluster subdivision, which the Planning Board must permit rather than it being available by right, cuts the lot minimum from 40,000 sq ft to 15,000 (0.34 acre), the width from 200 ft to 80 ft, the front yard from 35 ft to 30 ft and the side yard from 35 ft to 10 ft.

• A cluster must keep at least 50% of the parent parcel and 50% of its buildable land in permanent conservation area, with at least one preserved parcel of 3 acres or more.
• Town-wide setbacks can exceed every figure here: 100 ft from the top of the bank of any watercourse, 250 ft from a watercourse feeding the Watervliet reservoir and 500 ft from its high-water mark.
• A further rule bars any structure between the top of a bank and a line struck at 12 degrees from the toe of the slope, with 30 ft more beyond that line.
• The 200 ft width is measured at the building line, not at the street.
• On Route 20 west of Route 155, on Route 155, Route 146 and Rapp Road, the setback and the lot area are measured from the future right-of-way line where one has been established.
• An accessory structure belongs in the rear yard, 5 ft from a lot line if minor, 10 ft if major and 15 ft if over 1,000 sq ft, and is capped at 15 ft tall.

Rural Agricultural District - 3 - A cluster subdivision, which the Planning Board must permit rather than it being available by right, cuts the lot minimum from three acres to 20,000 sq ft (0.46 acre), the building line width from 200 ft to 80 ft and the side yard from 50 ft to 10 ft.

• A cluster subdivision must keep at least 50% of the parent parcel and 50% of its buildable land in permanently protected conservation area.
• Town-wide setbacks can exceed every figure here: 100 ft from the top of the bank of any watercourse, 250 ft from a watercourse feeding the Watervliet reservoir and 500 ft from its high-water mark.
• A further rule bars any structure between the top of a bank and a line struck at 12 degrees from the toe of the slope, with 30 ft more beyond that line.
• Farm buildings are exempt from the height cap if they stand 100 ft from any property line.
• On Route 20 west of Route 155, on Route 155, Route 146 and Rapp Road, the setback and the lot area are measured from the future right-of-way line where one has been established.
• The 200 ft width is measured at the building line, not at the street.

Rural Agricultural District - 5 - A cluster subdivision, which the Planning Board must permit rather than it being available by right, cuts the lot minimum from five acres to 30,000 sq ft (0.69 acre), the building line width from 200 ft to 80 ft and the side yard from 50 ft to 10 ft.

• A cluster subdivision must keep at least 50% of the parent parcel and 50% of its buildable land in permanently protected conservation area.
• Town-wide setbacks can exceed every figure here: 100 ft from the top of the bank of any watercourse, 250 ft from a watercourse feeding the Watervliet reservoir and 500 ft from its high-water mark.
• A further rule bars any structure between the top of a bank and a line struck at 12 degrees from the toe of the slope, with 30 ft more beyond that line.
• Farm buildings are exempt from the height cap if they stand 100 ft from any property line.
• On Route 20 west of Route 155, on Route 155, Route 146 and Rapp Road, the setback and the lot area are measured from the future right-of-way line where one has been established.
• The 200 ft width is measured at the building line, not at the street.

Residential Overlay District - 30, Residential Overlay District - 40 - The overlay publishes no dimensions of its own, and the underlying district's figures govern until the planning board acts. What it offers is an increase of up to 100% in a subdivision's density, a discretionary grant rather than an entitlement.

• The increase is available only where the subdivision has a right of ingress or egress directly onto a collector street without crossing a non-collector one.
• NYS Routes 20 and 146 are collector streets by name.
• The town board may add other collector streets on the recommendation of the planning board and the superintendent of highways.

Townhouse Dwelling - Lot area is not set for this district; what governs instead is density, six units per acre of buildable land, and no more than four units may be attached by common or party walls.

• The 20 ft width is the width of an individual townhouse lot, and each unit must hold at least 1,000 sq ft of habitable area and be at least 20 ft wide.
• Nothing here is permitted by right: a townhouse dwelling is authorised by site plan approval under § 280-53.
• Nothing may stand within 100 ft of the top of the bank of any watercourse or body of water, within 250 ft of the bank of a watercourse feeding the Watervliet reservoir, or 500 ft of the reservoir.
• No structure may stand between the top of a bank and a line struck at 12 degrees from the toe of the slope, with a further 30 ft setback beyond that line.
• On Route 20 west of Route 155, on Route 155, Route 146 and Rapp Road, both the setback and the lot area are measured from the future right-of-way line wherever one has been established.
• Height is measured from finished grade to a point midway between the highest and lowest points of the roof rather than to the ridge.

Transit Oriented Development - No building may stand within 100 ft of the boundary of a residential district outside the TOD. The 55 ft height applies only more than 150 ft from such a boundary; between 100 and 150 ft of one, and within 75 ft of Western Avenue, the cap is 35 ft.

• Density is 16 dwelling units per acre of buildable land for a multiple-family building and 12 for a mixed-use one.
• West of Rapp Road the only use allowed is a multiple-family dwelling, which may carry ground-floor uses permitted in GB, and a nonresidential use there is capped at 4,000 sq ft of gross floor area.
• Single-family and two-family dwellings, drive-through restaurants and car lots are prohibited, though selling and servicing electric and similar green-technology vehicles is allowed by special permit.
• Nothing here is by right: uses come from the GB and MR lists by site plan approval or special use permit.
• Nothing may stand within 100 ft of the top of the bank of any watercourse or body of water, within 250 ft of the bank of a watercourse feeding the Watervliet reservoir, or 500 ft of the reservoir.
• On Route 20 west of Route 155, on Route 155, Route 146 and Rapp Road, both the setback and the lot area are measured from the future right-of-way line wherever one has been established.