DOB Glossary

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The design and construction of buildings for accessibility and use by persons with physical disabilities, complying with the Federal ADA Standards; US Housing & Urban Development (HUD); BC Chapter 11, BC Appendices E, N and P; and/or ICC/ANSI A117.1.

Adult Establishment
A commercial establishment that can include an adult bookstore, adult-only eating or drinking establishment, adult theater, other adult commercial establishment, or any combination of these places, and regularly features films, motion pictures, or photographic material which is sexually explicit. Other establishments may provide live entertainment where patrons are exposed to specified anatomical areas of the staff.

An alteration project always results in a new or amended Certificate of Occupancy. The work may involve a substantial enlargement or reduction in the size of the building or involve a major change to the entrance/exit of a building, the zoning use group, and/or Building Code occupancy use.

The use of proper anchors (fasteners) for supporting and securing structural members (wall, column, deck, post or beam), fixtures and equipment; structures supported by attachment to an exterior wall shall be positively anchored to the primary structure and designed for both vertical and lateral loads, as applicable.

Architectural Details
A wide range of façade elements (i.e. cornices, moldings, façade sculpture) which, as part of older buildings, could project into the public right of way.

Architectural Terracotta
A hard-burnt glazed or unglazed clay used in building construction as cladding or veneer for exterior walls; terracotta can be plain or ornamental, machine-extruded or hand-modeled and is usually larger than brick or facing tile

A space below grade that is adjacent to a building, open to the outer air, and enclosed by walls.

Any encroachment allowed by a governing agency, such as DOB or DOT, without any need for a special permit or variance. For example, the as-of-right encroachment of architectural details of a building cannot project more than three inches into the public right of way, per the Building Code.

Attached Lighting
Lighting fixtures and devices attached to the building façade.

An architectural projection that provides weather protection, identity or decoration and is wholly supported by the building it is attached to; an awning is comprised of a lightweight frame structure with a covering attached.


An above grade extension enclosed by a wall or balustrade (railing) on the outside of a building, with access from an occupied space

A story partly below the curb level but having at least one-half of its height above the curb level; except that where every part of the building is set back more than twenty-five feet from a street line, the height must be measured from the adjoining grade elevations calculated from final grade elevations taken at intervals of ten feet around the exterior walls of the building. A basement must be counted as a story in determining height.

Board of Standards and Appeals (BSA)
Has the power to modify the Zoning Resolution after review and public hearing. Approved BSA resolution with BSA stamped plans is required in order to proceed with DOB application review (ZR 72-00).

Building Parapet
A vertical extension of the exterior wall at the edge of a roof, terrace, balcony, walkway or other structure, which acts as a safety barrier.

Building Systems Work
The installation, modification, or upgrade of existing building systems; including plumbing, boiler, sprinkler, standpipe, fire alarm, HVAC, and fire suppression systems; if modifications to these systems are part of the work scope, the alteration must include these in the project scope of work.


A permanent structure or architectural projection of rigid construction with a covering over it that is attached and provides weather protection, identity, or decoration, which must be structurally independent or supported by attachment to a building on one end and by not fewer than one stanchion at the outer end.

Cavity Wall
An exterior wall, usually of masonry, consisting of an outer and inner wythe (vertical section of bricks) separated by a continuous air space, but connected together by wire or sheet-metal ties; the air space provides thermal insulation.

An enclosed space having more than one-half of its height below the curb level; except that where every part of the building is set back more than twenty-five feet from a street line, the height shall be measured from the adjoining grade elevations calculated from final grade elevations taken at intervals of ten feet around the exterior walls of the building. A cellar cannot be counted as a story.

Certificate of Occupancy
A new or amended Certificate of Occupancy is issued for a building upon completion of a project involving a change in occupancy or use, or when there are other changes that affect the existing Certificate of Occupancy. For example, if an existing building is vertically enlarged by a complete story, or if the use of a building is changed from commercial to residential, a new or amended C of O would be required. Reference AC 28-118.3 for more information.

The following may also be issued:

  • A Partial Certificate of Occupancy, for a portion of a building, depending on construction progress and safety
  • Temporary Certificate of Occupancy, for a limited duration of time, because the project is not closed due to certain final inspections not being performed, final surveys not submitted, etc., per AC 28-118.16.

A protective or insulating layer fixed to the outside/exterior walls of a building or another structure.

Code and Zoning Determinations
Determination requests are issued to the Borough Commissioner's office for an objection raised by a plan examiner or a possible future objection for an application not yet filed (pre-determination). To request a determination, file a Zoning Resolution Determination Form (ZRD1 Form) (ZRD1 Instructions) or a Construction Code Determination Form (CCD1 Form) (CCD1 Instructions). Forms must be signed and sealed by a professional. Determination requests are limited to one request per form and must cite all related Code or Zoning sections.

Refers to quality assurance testing process that verifies, and documents that the selected building systems have been designed, installed, and function according to the owner’s project requirements and construction documents, and to minimum Code requirements. Mandatory when the permitted equipment exceeds a total heating capacity of 600 kBTU/h.

Per the Zoning Resolution, a conversion is a change of use. A use is any purpose for which a building, structure, or open tract of land is designed, arranged maintained or occupied.

A protective cap, top, or cover of a wall, parapet, pilaster, or chimney; coping is often made out of stone, terracotta, concrete, metal, or wood; coping may be flat, sloping, double-beveled or curved to shed water to protect masonry below from penetration of water from above.

A projection that crowns or finishes part of the building element to which it is affixed; the exterior trim of a structure at the meeting of the roof and wall, usually consisting of bed molding, soffit, fascia and crown molding

A concrete border parallel and adjacent to the roadway that forms a sidewalk edge, which may require a steel face or a row of joined stones.

Curb Cut
An angled cut to the edge of a sidewalk to permit vehicle access to a driveway, garage, parking lot, loading dock or drive-through facility.

Curb Level
For the purpose of measuring the height of any portion of a building, with respect to ZR and MDL, is the level of the curb at the center of the front of the building; except that where a building faces on more than one street, the curb level is the average of the levels of the curbs at the center of each front. Where no curb elevation has been established the average elevation of the final grade adjoining all exterior walls of a building, calculated from grade elevations taken at intervals of ten feet around the exterior walls of the building, shall be considered the curb level, unless the city engineer shall establish such curb level or its equivalent.

Curb Line
The line coincident with the face of the street curb adjacent to the roadway.

Curtain Wall
The outer skin of a building; nonbearing wall of glass, metal, or masonry attached to the structural frames of a building exterior


Development Rights
Development rights generally refer to the maximum amount of floor area permissible on a zoning lot. When the actual built floor area is less than the maximum permitted floor area, the difference is referred to as unused development rights. Unused development rights are often described as air rights.

Distinctive Sidewalk
A sidewalk with different material, color, scoring and/or dimensions than the standard sidewalk as prescribed by DOT. Distinctive sidewalks require Public Design Commission (PDC) Approval.

Storm water falling on the sidewalk and roadway adjoining the property frontage must be discharged into a street drainage system. Storm water falling on-site, as allowed by DEP, is discharged into an on-site drywell or similar, or discharged through a connection to the storm water system or Green Infrastructure at the street.

Any building or structure or portion thereof which is occupied in whole or in part as the home, residence or sleeping place of one or more human beings.


Elevation in Flood Zones
Elevating a building to ensure that lowest occupied floor is above the flood levels per FEMA flood maps and as described in BC Appendix G and ZR Article VI, Chapter 4.

Public right of way encroachments are intrusions from portions of the building onto a sidewalk and/or street, including but not limited to; vaults, steps, stoops, footings, fences, and retaining walls.

Per the Zoning Resolution, an enlargement is an addition to the floor area of an existing building or zoning lot, or an expansion of a use to an area not previously used for such purpose. Per the Building Code, an enlargement is any addition of gross floor area to a building.

Excavation is the process of moving earth, rock or other materials with tools, equipment or explosives. It includes earthwork, trenching, wall shafts, and tunneling underground. Per BC 3302.1, it’s the removal of earth from its natural position; except for any incidental removal that occurs during the course of auguring, drilling, vibrating, or driving. Coordination with FDNY is required.


The exterior wall of the building often used to install antennas.

As applied to a part or parts of a building, means such part or parts are made of non-combustible materials with standard fire-resistive ratings not less than those required for the corresponding part or parts of a fireproof dwelling.

Foundations are typically comprised of concrete with wood or steel structural elements driven into the ground or cast in place. Foundations maybe a mat foundation, a slab-on grade foundation or composed of an individual or strip footings.

Floor Area
As used in MDL Article 7B, gross floor area shall be measured to the outside surface of exterior walls and includes shafts and stairways and similar. However, clear floor area or interior floor area is measured to the interior finish surfaces of walls, typically within a room or dwelling unit.

Frame Dwelling
A dwelling in which the exterior walls, or any structural parts of the walls, are made of wood




High Hazard Occupancy/Use Group
High-Hazard Group H occupancy includes, among others, the use of a building or structure, or a portion of the building, that involves the manufacturing, processing, generation or storage of materials that constitute a physical or health hazard in excess quantities, as per BC Tables 307(1) and 307(2). ZR Use Group 18 addresses hazardous materials.


Interim Multiple Dwelling (IMD)
MDL §281 sets forth the criteria for becoming a Loft Building, also known as an interim multiple dwelling (IMD), as adjudicated by the Loft Board. MDL 280 states that IMDs are de facto multiple dwellings, meaning that IMDs are lawfully existing, which is a design consideration, even though the legalization process, i.e. the process to ensure statutory compliance as required to get a Certificate of Occupancy, may not have started.


Joint Living Work Quarters for Artists (JLWQA)
A type of loft unit, as described in MDL Article 7B, Zoning Use Group of 17D; an artist is a person who is regularly engaged in the fine arts or in the performing or creative arts, and who is certified by the City’s Department of Cultural Affairs and/or State Council on the Arts.




Layout Changes
Include changes to floor layouts that add, relocate, remodel, enlarge or reduce the size of interior rooms while maintaining the same building envelope.

Letter of No Objection (for units under the Loft Law)
Before the owner can obtain a permit to do any other work within building, but not directly related to the IMD unit(s), the owner must get a LNO from the Loft Board.

Licensed Place of Assembly
This term was replaced by ‘Place of Assembly Certificate of Operation’ in the NYC 2008 Building Code. Existing places of assembly constructed under the 1938 Code used this term to identify when the lawful use, occupancy or operation of the space was contingent upon the issuance of a license by the NYC Fire Department, the Police Department or the Department of Licenses.

A horizontal structural member (such as a beam) over an opening for doors and windows, which carriers the weight of the wall above; lintels are usually made of steel, pre-cast concrete, stone or wood.

A loft is a building or space within a building designed for commercial or manufacturing use, generally constructed prior to 1930. In certain manufacturing districts, lofts may be converted to residential use by CPC special permit.

Loft Board
The New York State Legislature established the New York City Loft Board, a nine-member board appointed by the Mayor, in 1982 to regulate the conversion of certain buildings that were constructed for commercial and manufacturing use to lawful residential use.

Loft Board Certification
Prior to obtaining a permit for work needed to legalize the IMD unit(s), once all objections and issues are resolved between the owner and the occupants, the Loft Board will issue a letter certifying compliance with all Loft Board requirements and has no objections.

Lot Line Windows
Windows of a building exterior wall located on the side or rear property zoning or tax lot lines. Such lot line windows require special Code compliance review, depending on the building type and building construction class, to determine the allowable window sizes, quantity, and fire protection needed.


Major Building
An existing building 10 or more stories or 125 ft. or more in height, or an existing building with a building footprint of 100,000 sf. or more regardless of height, or an existing building designated by the Commissioner due to unique hazards associated with the construction or demolition of the structure.

Mixed Building
Per the Zoning Resolution, a mixed building is a building used partly for residential use and partly for community facility, and/or commercial use.

Mixed Occupancy
Per the Building Code, a building with mixed occupancy would contain two or more occupancy classifications. These occupancy classifications may or may not match the zoning use groups.  

Mixed Use
Per the Building Code, a building with mixed occupancy would contain two or more occupancy classifications. These occupancy classifications may or may not match the zoning use groups.

A monopole is a single pole structure that supports an antenna or sign. A monopole may typically be 50 feet to 120 feet in height but can vary. As required by Code, a monopole is bolted to or embedded in a concrete foundation and sufficiently sized to resist the imposed loads of the structure.


Generally composed of mesh, side ropes, ties and other components; netting is used at various construction sites, especially high-rise buildings; netting is installed on scaffolding to protect pedestrians and workers from falling debris

New Building (NB)
A new building project is a permanent enclosed construction over a plot of land, having a roof and windows, used for any of a wide variety of activities, such as living and entertaining if residential in nature.

Non-Complying Use
Any lawfully existing building or other structure that does not comply with applicable bulk regulations either on December 15, 1961 or as a result of a subsequent zoning amendment. A non-compliance is a failure of a building or other structure to comply with any bulk regulation(s).

Non-Conforming Use
Per ZR 12-10, non-conforming use is any lawful use of a building that does not conform to any one or more of the applicable zoning use regulations of the district in which it is located. A non-conforming use results from failure to conform to the applicable district regulations on either permitted Use Groups or performance standards. Existing non-conforming use to remain per ZR 52-00.


The purpose or activity that the building or space is used or is designed, arranged or intended to be used.

Occupancy Classification
The use as defined in the Building Code, and is the purpose or activity a building or space is used or is designed, arranged or intended to be used

Occupant Load
The number of persons for which the means of egress of a building or portion thereof is designed.

One-Family Home
Any building or structure designed and occupied for residence purposes on a long-term basis for more than a month at a time by not more than one family as required by the Housing Maintenance Code (HMC).

Two-Family Home: Any building or structure designed and occupied for residence purposes on a long-term basis for more than a month at a time by not more than two families as required by the HMC.

A condition where the number of occupants exceeds what is specified on the Certificate of Occupancy or what is allowed in BC 1004.1. Also, the FDNY may determine that a threat exists to the safety of the occupants at the premises by reason of the number of people in the space and/or the presence of people sitting and/or standing in locations that obstruct or impede access to exits, including aisles, passages, corridors, stairways.


Parapet Wall
A continuous extension of the exterior wall installed entirely above the roof of the building.

Partial Demolition
Any construction that involves the removal, replacement or repair of load bearing and/or non-load bearing interior partitions, changes to structural elements (interior or exterior), facade changes, upgrades or portions thereof while maintaining the existing structure.

Penalties for Work Without a Permit
Performing work without a permit may result in violations, court appearances, and civil/criminal penalties. However, some minor alterations, ordinary repairs, or replacement of faucets, toilets, and sinks do not require permit and someone without a license may do this work as per AC 28-105.4.

Rectangular or semicircular projections from a wall surface for reinforcement or use as a simulated pillar in entrances and other door openings; pilasters may also be installed as projections of the exterior wall.

Plan Examination and Approval
Your project cannot begin until the project plans are reviewed by a Department Plan Examiner and approved or accepted if Professionally Certified. Disapproved applications result in the issuance of objections that must be resolved before obtaining approval. Your design professional schedules appointments with Department Plan Examiners to resolve objections.

Place of Assembly 
Place of Assembly occupancy classifications are for gatherings of people for purposes like civic, social or religious functions, recreation, food or drink consumption, awaiting transportation, or similar group activities, when occupied by 75 people or more. A Place of Assembly Certificate of Operation is required.

Place of Assembly Certificate of Operation (PACO)
Following the approval of plans/alternate plans in accordance with BC 1028.1.3, and successful completion of DOB inspection, an initial Place of Assembly Certificate of Operation (PACO) is issued, effective for one year. Afterwards, an annual FDNY inspection for a PACO renewal is required (FC 105.6).

A raised area within a building used for worship, the presentation of music, plays or other entertainment; the head table for special guests; the raised area for lecturers and speakers; boxing and wrestling rings; theater- in-the-round stages; and similar purposes wherein there are no overhead hanging curtains, drops, scenery or stage effects other than lighting and sound. A temporary platform is installed for not more than 30 days.

Pointing and Repointing
The mortar between the joints of masonry units such as bricks, stone etc.; repointing involves removal and replacement of existing mortar with new mortar.

Pre-existing Violation
A “pre-existing violation” is a violation issued by the Department of Buildings where a Notice of Violation, administrative summons, criminal court summons or other process was issued prior to the date of issuance of the initial permit for work.

Privately-owned Public Space (POPS)
An amenity provided and maintained by the property owner for public use, usually in exchange for additional floor area. Located mainly in the high-density, central business districts of Manhattan, these spaces are typically in the form of an arcade or a public plaza with seating and landscaping and may be located within or outside a building.

Property Line
Property lines detail the legal boundary, or metes and bounds, of a parcel of land.

Project Application for Permit
Refers to the submission of construction documents prepared by a registered design professional (RDP - Professional Engineer or Registered Architect) and filed for approval with the Department. In certain cases, the RDP may – with owner’s consent – opt for professional certification of applications (self-certifying compliance with applicable Codes and laws) and not require Department review.

Project Completion
To close the permit issued for the project, the Owner/Applicant/Contractor must ensure the permitted work, once completed, must be inspected for final sign-off and a work completion notification submitted to the Department. In certain cases, at completion of the work a letter of completion may be issued.

Public Plaza
A public plaza is a privately owned open area adjacent to a building and accessible to the public. It must generally be at the level of the sidewalk it adjoins and be unobstructed to the sky except for seating and other permitted amenities. In certain high-density zoning districts, a floor area bonus is available for the provision of a public plaza.

Public Right of Way
The public street space beyond the private property line, including the roadway sidewalk.

Public Space
An open space outside of a building, which is dedicated or devoted to public use by lawful mapping or by any other lawful procedure




Registered Land Surveyor
A person licensed and registered to practice the profession of land surveying under the education law of the State of New York.

Changes to an existing building, including the remodeling or replacing of outdated or damaged structures and materials, and the partial demolition of interior partitions. Building renovations can also include the installation or replacement of building systems, devices or equipment, materials, or parts, as part of regular maintenance of the building. Renovation projects do not impact the existing means of egress (entrance/exit), do not change the use of the building or space, and do not increase the occupant load.

Per the Building Code, Residential Group R includes “the use of a building or structure, or a portion thereof, for dwelling or sleeping purposes.” If there are three or more dwelling units in the building, it must be classified as a multiple dwelling and is subject to the Multiple Dwelling Law (MDL). Residences can either be transient, where the occupancy of a dwelling unit or sleeping unit is not more than 30 days, or non-transient, which could include community facilities with sleeping accommodations.

Per the Zoning Resolution (ZR), Residential as applied to building use, is a building with one or more dwelling units or rooming units, but with exceptions; for example, hotels and community facilities with sleeping accommodations are not residences per the ZR. Residential can also describe the type of zoning district; for example, hotels are not allowed in residential districts, while community facilities can be located in residential districts.

Retaining Wall
Structures that are used to bound soil between two different elevations. Per BC 1801.3, a wall that resists lateral or other forces caused by soil, rock, water or other materials, limiting lateral displacement and the movement of the supported materials. Basement walls and vault walls that are part of buildings and underground structures, including but not limited to utility vault structures, tunnels and transit stations, are not considered retaining walls.

Revocable Consent
Revocable Consent, by New York City Charter, Chapter 14 §362(d), means a grant of a right, revocable at any time by New York City, for allowable private use or improvements on, over and under New York City’s streets and sidewalks; the NYC Department of Transportation has jurisdiction over revocable consent.


An enclosed space extending through one or more stories of a building connecting a series of openings, or any story or stories and the roof, and includes exterior and interior shafts whether for air, light, elevator, dumbwaiter, enclosed vertical stairways, or any other purpose.

Sidewalk Vaults
Any space below the surface of a sidewalk and/or street, which is covered over, except those openings that are used exclusively as places for descending, by means of steps, to the cellar or basement of any building.

Site Safety Plans/Projects
A Site Safety Plan is required for all major buildings, including new buildings, alterations and demolition projects that are 10 stories or greater, or façade work on buildings that are 15 stories or greater, as detailed in BC 3310. The requirements for a Site Safety Plan includes all requirements needed to protect the public areas and adjoining properties by providing a detailed list of construction logistics, including the locations of all forms of site protection equipment, such as fences, sidewalk sheds, locations of adjoining buildings, safety netting, etc. as outlined in AC 28-110.1.

Special Amusement Building
A temporary or permanent building occupied for amusement, entertainment or educational purposes that provides a walkway along or that contains a device or system that takes passengers around or over a course in any direction as a form of amusement (i.e. haunted house, laser tag arena, mazes). Exits from the structures may not be readily apparent due to visual or audio distractions or an intentionally puzzling path egress path.

Special and Progress Inspections
Special inspections are inspections of selected materials, equipment, installation, fabrication, erection or placement of components and connections, to ensure compliance with approved construction documents and referenced standards. Special Inspection and Progress Inspections are performed by specialists experienced in the field and registered to perform these inspections with the Department. Only registered SIAs, their representatives, or qualified professionals can perform Special and Progress Inspections.

Storm Water Drainage
Storm water falling on all water-resistant surfaces within a property must be discharged into either a public storm water or combined sewer system, or into an on-site private storm water disposal system such as drywell (well used to move surface water underground).

A space within a building utilized for entertainment or presentations, which includes overhead hanging curtains, drops, scenery or stage effects other than lighting and sound.

Storm Enclosures
Temporary and seasonal vestibules, which are allowed as supplementary entrances to buildings.

A story is a floor level in a building that is significant in both the Code and Zoning. For example, if a third story is added to a one- or two-family home, it could trigger additional fire protection requirements in the Code. Basements are stories, while cellars are not and an attic may be considered a story.

Street Line
The lot line fronting a street, which separates the street from other non-street land.

Street Wall
An exterior wall or façade of a building located at the street line.


Tax Lot
A tax lot is used to describe a tract of property on the City’s tax map on which property taxes are assessed.

Transfer of Development Rights (TDR)
Allows for the transfer of unused development rights from one zoning lot to another in limited circumstances, usually to promote the preservation of historic buildings, open space or unique cultural resources. A TDR may be permitted where the transfer could not be accomplished through a zoning lot merger. In the case of a landmark building, for example, a transfer may be made by the City Planning Commission special permit from the zoning lot containing the designated landmark to an adjacent zoning lot or one that is directly across a street or, for a corner lot, another corner lot on the same intersection.


The purpose for which a building, structure, building area/space or open tract of land is designed, arranged maintained or occupied.

Use Group
The use as defined in ZR Section 12-10, and is any purpose for which a building or other structure, or an open tract of land, may be designed, arranged, intended, maintained or occupied; furthermore the use is any activity, occupation, business or operation carried on, or intended to be carried on.




Window Well
A window designed to keep the soil away from openings in foundation walls while allowing proper grading and drainage away from the structure and allows sunlight into a below-grade room (basement) that would otherwise require artificial lighting.

Work Permit
Following project plan approval, a work permit is issued to a licensed Contractor to begin construction. The Department licenses many trades, and only a registered Contractor can perform the work. Department licenses, registrations and certifications regulate the industry and work to prevent unqualified individuals from risking the health, safety and welfare of the public.






Zoning/The Zoning Resolution (ZR)
The aim of zoning is to promote an orderly pattern of development and to separate incompatible land uses, like industrial use from residential, to ensure a pleasant environment. The Zoning Resolution is a legal instrument to regulate and establish limits on the use of land, building size, shape, height, and setback.

Zoning Lot
A zoning lot is a tract of land where specific zoning regulations apply. Zoning lots don’t have to coincide with a tax lot and can consist of one or multiple tax lots. Multiple buildings can be present on a single zoning lot.