NYC Zoning Handbook: Appendix D
An accessory use is a use which is clearly incidental to and customarily
found in connection with the principal use. Such accessory use must be
conducted on the same zoning lot as the principal use to which it is
related, unless modified by the district regulations.
Air Rights (See Development Rights)
An arcade is a continuous covered area which opens onto a street or a
plaza. It is unobstructed to a height of not less than 12 feet, and must
be accessible to the public at all times.
An attached building is a building on a zoning lot that abuts two lot
lines other than a street line.
In certain lower density contextual districts, there is an increase in
the base maximum FAR, of up to 20 percent, for floor area which is
beneath a pitched roof and has structural headroom of between five and
An authorization is a discretionary action taken by the City Planning
Commission, usually after a 30-day informal referral to the affected
community board. Generally, a resolution authorizing the action is
adopted by the Commission at a public meeting.
The base plane is a horizontal plane from which the height of a building
is measured in lower density contextual districts. The level of a base
plane may be the curb level, the level of the natural grade at the front
yard line, or the average elevation of the final grade surrounding a
A basement is a story that has less than one-half of its height below
A block is a tract of land bounded by streets or by a combination of
streets, public parks, railroad rights-of-way, pierhead lines and
A building is a structure which has one or more floors and a roof and
which is permanently affixed to the land.
The building envelope is the maximum contour of a building permitted by
height and setback controls.
A mixed building is a building in a commercial district used partly for
residential use and partly for community facility or commercial use.
Bulk is the term used to describe the size (including height and floor
area) of buildings.
A cellar is a portion of a building that has more than one-half of its
floor-to-ceiling height below curb level.
Certification is a determination made by the Department of City Planning
that an application is complete, complies with specific sections of the
Zoning Resolution, and is ready for the formal public review process (ULURP).
It is also a ministerial action taken by the City Planning Commission or
its chairperson in accordance with certain provisions of the Zoning
Resolution to achieve specific planning objectives.
Any building occupied only by commercial uses is a commercial building.
A Commercial District is designated by the letter C (C1-2, C3, C4-7, for
A commercial overlay is a small portion of a residential district --
usually the first and second floors of buildings fronting on major
avenues or wide streets -- which is zoned for retail and service stores.
A commercial overlay is shown on the zoning maps as a pattern
superimposed on a residential district.
A commercial use is any use listed in Use Groups 5 through 16.
Community Facility Building
A community facility building is any building occupied only by a
community facility use.
Community Facility Use
Any use listed in Use Groups 3 or 4, except open uses, is a community
Contextual zoning is zoning that regulates the height and bulk of new
buildings, their setback from the street line, and their width along the
street frontage, to conform with the character of the neighborhood.
A court is any open area other than a yard or portion thereof, which is
unobstructed from its lowest level to the sky, and which is bounded by
building walls, or building walls and one or more lot lines.
Curb level is the mean level of the curb adjoining a zoning lot. This
provides the base from which height and setback computations are made
and building stories counted.
Density refers to the maximum number of dwelling units or zoning rooms
permitted on a site. It is regulated by the minimum number of square
feet of lot area required for each dwelling unit or zoning room.
A detached building is a freestanding building on a zoning lot that does
not abut any other building on an adjoining zoning lot and where all
sides of the building are surrounded by open areas within the zoning lot
or street lines.
A development includes: a) the construction of a new building or other
structure on a zoning lot; b) the relocation of an existing building to
another lot; or c) the use of a tract of land for a new use.
Development Rights (or Air Rights)
Development rights generally refer to the maximum amount of floor area
permissible on a zoning lot.
The difference between the maximum permissible floor area and the built
floor area on a zoning lot is called "unused development rights."
Under New York City's zoning law, the unused development rights of a lot
may be sold and transferred as-of-right to adjacent lots only through a
zoning lot merger, except in the case of designated landmarks where such
transfer is possible by a special permit without a zoning lot merger.
Unused development rights are often described as "air rights."
A dwelling unit consists of one or more rooms which contain lawful
cooking and sanitary facilities in a residential building or residential
portion of a building.
An enlargement is a built addition to an existing building that
increases the floor area of the building.
An extension is an expansion of the amount of existing floor area
occupied by an existing use.
The floor area of a building is the sum of the gross area of each floor
of the building, excluding cellar space, floor space in open balconies,
elevator or stair-bulkheads and, in most zoning districts, floor space
used for accessory parking that is located less than 23 feet above curb
Floor Area Ratio
Floor area ratio (FAR) is the total floor area on a zoning lot divided
by the area of that zoning lot. Each zoning district classification
contains an FAR control which, when multiplied by the lot area of the
zoning lot, produces the maximum floor area allowable on such lot.
Group Parking Facility
A group parking facility is a building or lot used for parking more than
one motor vehicle.
The height factor of a building is equal to the total floor area of the
building divided by its lot coverage.
Joint Living-Work Quarters For Artists
Joint living-work quarters for artists is a space for an artist and the
artist's family in a non-residential building used for living quarters
and a studio workshop.
Large-Scale Community Facility Development
A large-scale community facility development is a development or
enlargement predominantly for community facility uses in residential
districts and in C1, C2, C3 and C4-1 districts. The development must be
on a tract of land in single ownership that is at least three acres and
may include existing buildings.
Large-Scale Development, General
A general large-scale development is a development or enlargement for
any uses permitted by the underlying district regulations in commercial
districts (except C1, C2, C3 and C4-1 districts) and in all
manufacturing districts. The development must be on a tract of land in
single ownership that is at least 1.5 acres and may include existing
Large-Scale Residential Development
A large-scale residential development is a development predominantly for
residential uses in residential districts and in C1, C2, C3 and C4-1
districts. The development must be on a tract of land in single
ownership that is either at least three acres with a minimum of 500
dwelling units or at least 1.5 acres with a minimum of three principal
residential buildings. Existing buildings may not form any part of a
large-scale residential development.
Legally Required Window
A legally required window is a window required to light or ventilate a
living room under Section 4 of the New York State Multiple Dwelling Law.
Limited Height District
A limited height district is an overlay district superimposed on another
district which limits the height of buildings in certain areas
designated as historic districts by the Landmarks Preservation
A loft is a type of building generally constructed prior to 1930 for
commercial or manufacturing use, and which is now occupied (or has been
occupied) by manufacturing tenants.
The lot area is the area of a tract of land (zoning lot) in single
ownership located within a block.
Lot Area Per Dwelling Unit
The lot area per dwelling unit is the amount of lot area required for
each dwelling unit located on a zoning lot.
Lot Area Per Room
The lot area per room is the amount of lot area required for each room
located on a zoning lot.
A corner lot is either a zoning lot bounded entirely by streets or a
zoning lot which adjoins the point of intersection of two or more
streets. The only part of a zoning lot which can qualify as a corner lot
is that part of the lot that is within 100 feet of the intersecting
Lot depth is the mean horizontal distance between the front lot line and
rear lot line of a zoning lot.
An interior lot is any zoning lot that is neither a corner lot nor a
through-lot (see illustration above).
A split lot is a zoning lot located in two or more districts in which
different use, bulk, parking, or other regulations apply.
A lot line is a boundary of a zoning lot.
Lot Line, Front
A front lot line is a street line.
Lot Line, Rear
A rear lot line is any lot line of a zoning lot which is generally
parallel to any street line bounding such zoning lot and which does not
intersect with a street line.
Lot Line, Side
A side lot line is any lot line which is not a front lot line or a rear
A through lot is any zoning lot that is not a corner lot and that
connects two generally parallel streets (see corner lot illustration).
Lot width is the mean horizontal distance between the side lot lines of
a zoning lot.
The Manhattan Core extends from Battery Park on the south to West 110th
Street on the Upper West Side and East 96th Street on the Upper East
Side. It is the area covered by Manhattan Community Districts 1 through 8.
A Manufacturing District is designated by the letter M (M1-1, M2-2, for
A manufacturing use is any use listed in Use Group 17 or 18.
Non-Complying, Or Non-Compliance
A legal non-complying building is any building that was legal when it
was built which no longer complies with one or more of the present
district bulk regulations.
Non-compliance results when a building does not comply with any one of
such applicable bulk regulations.
Non-Conforming, or Non-Conformity
A legal non-conforming use is any use legal at its inception (whether of
a building or tract of land) which no longer conforms to any one or more
of the present use regulations of the district
Non-conformity results when a use does not conform to any one of such
applicable use regulations.
Non-Profit Hospital Staff Dwelling
A non-profit hospital staff dwelling is a dwelling owned by a non-profit
institution or subsidiary non-profit housing corporation which contains
dwelling units reserved exclusively for occupancy by staff members of
Open space is the part of a zoning lot including courts or yards, which
is open and unobstructed from its lowest level to the sky, except for
specifically enumerated obstructions, and is accessible to and usable by
all persons occupying dwelling units on the zoning lot.
A perimeter wall is the outermost wall of a building that encloses floor
area and rises from the base plane to a setback or the roofline.
A plaza is an open area accessible to the public at all times. It shall
not at any point be more than five feet above nor more than 12 feet
below the curb level of the nearest adjoining street. It must be
unobstructed from its lowest level to the sky except for certain
permitted obstructions such as arbors. awnings, ornamental fountains and
Public Parking Garage
A public parking garage is a building or part of a building in which:
- (a) Parking space is provided, except for commercial or public utility
vehicles or dead storage; and
- (b) Some or all of the parking spaces are non-accessory. A public
parking garage may include accessory off-street parking spaces limited
to such spaces which are accessory to other uses on the same zoning lot.
Public Parking Lot
A public parking lot is any tract of land which:
- (a) Is used for parking, except for commercial or public utility
vehicles or dead storage; and
- (b) Is not accessory to a use on the same or another zoning lot.
Railroad Or Transit Air Space
Railroad or transit air space is space directly over a railroad or
transit right-of-way or yard. After special review and under appropriate
conditions and safeguards, development may be permitted in such space.
Residence or Residential
A residence is a building or part of a building containing dwelling
units or rooming units, including one-family or two-family houses,
multiple dwellings, boarding or rooming houses or apartment hotels.
A Residence District is a district identified by the letter R (R5, R3-2,
R10H, for example).
A single-family residence is a building containing one dwelling unit
occupied by one family.
A two-family residence is a building containing two dwelling units
occupied by two families.
A residential use is any use listed in Use Group 1 or 2.
For zoning computations, a room is a space such as a living room or
bedroom. The basic living space in a dwelling unit (a living room,
dining area, and kitchen and bath) counts as 2 1/2 zoning rooms. Each
additional room in a dwelling unit, as defined in Section 4 of the
Multiple Dwelling Law, counts as another zoning room.
A semi-detached building is a building on a zoning lot that abuts or
shares one side lot wall with another building on an adjoining zoning
lot and where the remaining sides of the building are surrounded by open
areas or street lines.
Side Lot Ribbon
A side lot ribbon is that portion of the zoning lot that is contiguous
to, and extends along the entire length of, a side lot line from the
street line to an intersecting lot line.
An advertising sign directs attention to a business, profession,
commodity, service or entertainment conducted, sold or offered elsewhere
than upon the same zoning lot.
A business sign directs attention to a profession, business, commodity,
service or entertainment conducted, sold or offered upon the same zoning
A flashing sign is any illuminated sign, whether stationary, revolving
or rotating, which changes light or color.
An illuminated sign uses artificial light or reflected light from an
Sky Exposure Plane
A sky exposure plane is a theoretical inclined plane, through which the
height of a building may not penetrate, that is designed to provide
light and air at street level in medium and higher density districts. It
rises over the zoning lot at a ratio of vertical distance to horizontal
distance set forth in district regulations.
A front sky exposure plane begins above the street line (or where so
indicated, above the front yard line) at a specified height.
H=maximum height of front wall and starting point of sky exposure plane.
In the illustration, the building shown in the dashed line makes it initial setback below the maximum front wall height (h). The height of the front wall may not penetrate the sky exposure plane. The roof of the building, however, sets back at the point dictated by the sky exposure plane.
A rear sky exposure plane begins above a line at a distance from
and parallel to the street line and at a height set forth in
district regulations. The rear sky exposure plane is mandated
in R6A to R9A and R10A districts (narrow streets) but not in
R10 districts (wide streets).
H=height at which the rear sky exposure plane begins measured 100 feet from the street
In the illustration, the height of the rear wall of the building shown in the dashed line may not penetrate the rear sky exposure plane.
A story is that part of a building between the surface of one floor and
the ceiling immediately above. However, a cellar does not count as a
Any road, street, highway, expressway, boulevard, parkway, avenue, alley
or other public way, as shown on the City Map, or a way which is
intended for public use and provides a principal means of approach for
vehicles or pedestrians from a way shown on the City Map to a building
or structure. Street refers to the entire public right-of-way (including
A street line is a lot line separating the street from a lot.
A narrow street is a street that is less than 75 feet wide.
A street wall is a wall or portion of a wall of a building facing a
A wide street is a street that is 75 feet or more in width.
Through Block Arcade
A through block arcade is a continuous area within a building connecting
one street with another street or plaza or arcade adjacent to the
A use is any activity, occupation, business or operation carried on, or
intended to be carried on, in a building or on a tract of land.
Uses that have similar functional characteristics and/or nuisance
impacts are listed in one or more of 18 use groups that are ranked from
residential to industrial uses.
A yard is the required open area on a zoning lot along the lot lines. A
yard must be unobstructed from the lowest level to the sky, except for
certain permitted obstructions.
Yard Equivalent, Rear
A rear yard equivalent is an open area which may be required on a
through lot as an alternative to a required rear yard.
A front yard is a yard extending along the full length of a front lot
line. In the case of a comer lot, any yard extending along the full
length of a street line is considered a front yard.
A rear yard is a yard extending for the full length of a rear lot line.
A side yard is a yard extending along a side lot line from the required
front yard (or from the front lot line, if no front yard is required) to
the required yard (or to the rear lot line, if no rear yard is
required). In the case of a comer lot, any yard that is not a front yard
shall be considered a side yard.
Zero Lot Line Building
A zero lot line building is a freestanding building on a zoning lot that
abuts only one side lot line and does not abut any other building on an
adjoining zoning lot.
A zoning lot is a tract of land, either unsubdivided or consisting of
two or more contiguous lots of record, located within a block, which, at
the time of filing for a building permit, is designated as a tract to be
used, developed or built upon under single ownership. The ownership of a
zoning lot may be either single fee ownership or alternative ownership
arrangements as set forth in the definition of a zoning lot in Section
12-10 of the Zoning Resolution.
A zoning lot may be subdivided into two or more zoning lots, provided
that all resulting zoning lots and all buildings thereon shall comply
with all of the applicable provisions of the Zoning Resolution.
Zoning maps are maps that are included in the provisions of the Zoning
Resolution to indicate the location and boundaries of zoning districts.