What it costs to build an ADU in Colonie, NY

Airport Business Area - At least 35% of the lot has to be kept as green space, a floor on planted area rather than a ceiling on building coverage. It does not apply to a single-family or two-family dwelling.

• Under incentive zoning the Planning Board may cut green space in 5% steps to a floor of 15% and allow 8 dwelling units and 24,000 sq ft of commercial floor area per acre, for easements, land or cash.
• The base commercial density of 18,000 sq ft per acre applies to conservation development only.
• A nonresidential building, and its parking, loading, refuse and storage areas, has to sit at least 25 ft from the boundary of any adjacent lot in existing single-family use.
• More than 300 ft deep from the front lot line, a commercial or mixed-use building keeps 100 ft from a Single Family or Multifamily Residence District boundary, and parking, loading or storage 50 ft.
• Restaurants and convenience stores keep 100 ft from that boundary, and bars, fast food, supermarkets over 20,000 sq ft, service stations, repair shops and automatic car washes 200 ft.
• Much of this district also lies under the ANO overlay, which adds use conditions and sound-insulation requirements rather than dimensional ones.

Airport Noise Overlay - This overlay adds conditions to the uses the underlying district already permits, chiefly sound attenuation, and leaves lot size, setbacks and height to that district. Where the two conflict, the more restrictive rule governs.

• Uses already in place when the chapter took effect are exempt, as are temporary uses under five days, temporary nonresidential structures and accessory structures.
• Buildings on the National Register or a state or local historic register are exempt where insulation would compromise their integrity.

Conservation Development Overlay - Inside this overlay there is no mandatory minimum lot size and no minimum area, bulk or dimensional standard at all. The applicant proposes the lot dimensions and setbacks, and the Planning Board approves them on the final plan.

• How many dwellings are allowed is the acreage of unconstrained land times the underlying district's base residential density, with fractions rounded at 0.5.
• Permitted commercial floor area is worked out the same way, from the underlying district's base commercial density.
• At least 40% of the unconstrained land has to be shown as preserved, and constrained land is left out of the count entirely.
• Where the Planning Board allows constrained land to be disturbed, twice that area has to be set aside from the land of conservation value and treated as constrained.
• Wells and septic systems may sit in common open space, which allows a clustered layout.
• These rules reach all site plan development and subdivision here, apart from a minor site plan or minor subdivision, or where the Planning Board finds no reasonable basis for conservation development.

Cemetery - A nonresidential building here, with its parking, loading, refuse and storage areas, has to sit at least 25 ft from the boundary of any adjacent lot in existing single-family use. That distance is measured from the neighbour's line, not the district's.

• No minimum green space coverage applies in this district.
• Minimum front setbacks apply to new construction, not to the renovation of an existing structure.
• A corner lot has no rear yard and takes a full front yard on each street frontage, and so does a through lot.
• An unenclosed covered porch may project 10 ft into the front setback, and cornices, eaves and awnings 2 ft into any yard.

Commercial Office - Residential use here turns on parcel size. The base density of six dwelling units per acre applies only to a parcel of 15 acres or more, and on such a parcel the overall residential density may not go above it.

• On a parcel of 15 acres or more, setbacks from the original lot lines have to meet the MFR-C district's figures, an on-site rental office is required, and any percentage of mixed use is allowed.
• At least 35% of the lot has to be kept as green space, a floor on planted area rather than a ceiling on building coverage, and it does not apply to a single-family or two-family dwelling.
• Under incentive zoning the Planning Board may cut green space in 5% steps to a floor of 15% and allow 8 dwelling units and 24,000 sq ft of commercial floor area per acre, for easements, land or cash.
• A nonresidential building, and its parking, loading, refuse and storage areas, has to sit at least 25 ft from the boundary of any adjacent lot in existing single-family use.
• More than 300 ft deep from the front lot line, a commercial or mixed-use building keeps 100 ft from a Single Family or Multifamily Residence District boundary, and parking, loading or storage 50 ft.
• Restaurants and convenience stores keep 100 ft from that boundary, and bars, fast food, supermarkets over 20,000 sq ft, service stations, repair shops and automatic car washes 200 ft.

Commercial Office Residential, Office Residential - The building footprint is capped at 30,000 sq ft, and at least 35% of the lot has to be kept as green space, a floor on planted area rather than a ceiling on building coverage.

• Housing comes out of the commercial density: up to 80% of the base 18,000 sq ft per acre may be converted at 3,000 sq ft of commercial per dwelling unit.
• Under incentive zoning the Planning Board may cut green space in 5% steps to a floor of 15% and allow 8 dwelling units and 24,000 sq ft of commercial floor area per acre, for easements, land or cash.
• The green space minimum does not apply to a single-family or two-family dwelling.
• A nonresidential building, and its parking, loading, refuse and storage areas, has to sit at least 25 ft from the boundary of any adjacent lot in existing single-family use.
• More than 300 ft deep from the front lot line, a commercial or mixed-use building keeps 100 ft from a Single Family or Multifamily Residence District boundary, and parking, loading or storage 50 ft.
• Restaurants and convenience stores keep 100 ft from that boundary, and bars, fast food, supermarkets over 20,000 sq ft, service stations, repair shops and automatic car washes 200 ft.

Highway Commercial Office Residential - No maximum building footprint is published here, so building size is held by the 35% green space minimum and the yards. Green space is a floor on planted area, not a ceiling on building coverage.

• Housing comes out of the commercial density: up to 80% of the base 18,000 sq ft per acre may be converted at 3,000 sq ft of commercial per dwelling unit.
• Under incentive zoning the Planning Board may cut green space in 5% steps to a floor of 15% and allow 8 dwelling units and 24,000 sq ft of commercial floor area per acre, for easements, land or cash.
• The green space minimum does not apply to a single-family or two-family dwelling.
• A nonresidential building, and its parking, loading, refuse and storage areas, has to sit at least 25 ft from the boundary of any adjacent lot in existing single-family use.
• More than 300 ft deep from the front lot line, a commercial or mixed-use building keeps 100 ft from a Single Family or Multifamily Residence District boundary, and parking, loading or storage 50 ft.
• Restaurants and convenience stores keep 100 ft from that boundary, and bars, fast food, supermarkets over 20,000 sq ft, service stations, repair shops and automatic car washes 200 ft.

Historic Overlay - This overlay recognizes the Loudon Road and Watervliet Shaker historic districts. It sets no dimensional standard, additional setback, height limit or review requirement of its own, so a parcel inside it is governed by its underlying district alone.

Industrial - What limits building here is the yards, the 35% minimum green space coverage and the 75 ft height. The base commercial density of 18,000 sq ft per acre applies to conservation development only, and outside one the table states no density.

• Green space is a floor on planted area rather than a ceiling on building coverage, and it does not apply to a single-family or two-family dwelling.
• Under incentive zoning the Planning Board may cut green space in 5% steps to a floor of 15% and allow 8 dwelling units and 24,000 sq ft of commercial floor area per acre, for easements, land or cash.
• A nonresidential building, and its parking, loading, refuse and storage areas, has to sit at least 25 ft from the boundary of any adjacent lot in existing single-family use.
• More than 300 ft deep from the front lot line, a commercial or mixed-use building keeps 100 ft from a Single Family or Multifamily Residence District boundary, and parking, loading or storage 50 ft.
• Restaurants and convenience stores keep 100 ft from that boundary, and bars, fast food, supermarkets over 20,000 sq ft, service stations, repair shops and automatic car washes 200 ft.

Land Conservation - The only dimensional standard published for this district is a 35% minimum green space coverage. What may be built here is governed by the use table rather than by lot, yard or height limits.

• The district holds land that is already protected or preserved open space.
• A corner lot has no rear yard and takes a full front yard on each street frontage, and so does a through lot.

Multi-Family Residential - Six dwelling units per acre is a development-wide average, not a per-lot cap. The count for a whole development is set by the area of the original lot, roads, open space and recreation included, and an individual lot inside it may run higher.

• The building footprint is capped at 15,000 sq ft.
• A conforming lot may be subdivided for single-family or two-family houses under the conservation-subdivision standards, with the Planning Board setting lot sizes and setbacks from the new lot lines.
• In that case the overall density still has to stay at six units per acre, and setbacks from the original lot lines still have to meet this district's figures.
• At least 35% of the lot has to be kept as green space, a floor on planted area rather than a ceiling on building coverage, and it does not apply to a single-family or two-family dwelling.
• A nonresidential building, and its parking, loading, refuse and storage areas, has to sit at least 25 ft from the boundary of any adjacent lot in existing single-family use.
• A corner lot has no rear yard and takes a full front yard on each street frontage, and so does a through lot.

Neighborhood Commercial Office Residential - The building footprint is capped at 15,000 sq ft, and at least 35% of the lot has to be kept as green space, a floor on planted area rather than a ceiling on building coverage.

• Housing comes out of the commercial density: up to 80% of the base 18,000 sq ft per acre may be converted at 3,000 sq ft of commercial per dwelling unit.
• This district is exempt from the 25 ft setback between a nonresidential structure and an adjacent lot in existing single-family use.
• Under incentive zoning the Planning Board may cut green space in 5% steps to a floor of 15% and allow 8 dwelling units and 24,000 sq ft of commercial floor area per acre, for easements, land or cash.
• The green space minimum does not apply to a single-family or two-family dwelling.
• More than 300 ft deep from the front lot line, a commercial or mixed-use building keeps 100 ft from a Single Family or Multifamily Residence District boundary, and parking, loading or storage 50 ft.
• Restaurants and convenience stores keep 100 ft from that boundary, and bars, fast food, supermarkets over 20,000 sq ft, service stations, repair shops and automatic car washes 200 ft.

Planned Development District - A planned development district has no standing dimensions. It is created parcel by parcel by the Town Board, the approved plan is its dimensional standard, and the existing use, dimensional, sign and parking rules may all be altered to establish one.

• The figures for a particular planned development are in its own approving local law and site plan.
• Common open space of at least 35% of the whole PDD has to be provided in perpetuity, leaving out parking, garages, carports and other vehicle areas.
• A property owners' association or similar body has to hold and maintain that open space.
• A planned development with a significant number of dwellings has to be served by a community water system and by sewage disposal meeting Town, County and State requirements.

Single-Family Residential - An existing lot is developed under a different set of standards, set by the date the lot was created: a lot established before 8-6-1987 takes 12,000 sq ft and a lot established before 11-2-2006 takes 16,000 sq ft.

• A lot established before 8-6-1987 takes 75 ft of width, a 30 ft front yard, 5 ft and 14 ft side yards, a 25 ft rear yard, 40 ft and three storeys, and a footprint of up to 45% of the lot.
• A lot established before 11-2-2006 takes 80 ft of width, a 40 ft front yard, 10 ft and 20 ft side yards, a 25 ft rear yard and a 35% footprint.
• The 12,000 sq ft minimum does not apply to a lot on which a principal structure was lawfully built.
• Where a filed subdivision plan requires a deeper front setback than the chart, the filed plan governs (§ 190-26A).
• In a conservation subdivision the density is 2 dwelling units per acre and the Planning Board sets lot sizes during review; outside one, density is governed by the 18,000 sq ft lot minimum.
• A corner lot has no rear yard and takes a full front yard on each street frontage, and so does a through lot.