Code & MDL Reference Tables

  • Construction Classifications
    • 2014 Code Construction Classifications
    • Prior to 2014 Code Construction Classifications

  • Building Occupancy Classifications
    • 2014 Code Building Occupancy Designations
    • Prior to 2008 Code Building Occupancy Designations

  • Multiple Dwelling Classifications (MDL)

Construction Classifications

2014 Code Construction Classifications

Class

Short Description

I-A

3-Hour Protected (Non-Combustible)

I-B

2-Hour Protected (Non-Combustible)

II-A

1-Hour Protected (Non-Combustible)

II-B

Unprotected (Non-Combustible)

III-A

Protected Wood Joist (Combustible)

III-B

Unprotected Wood Joist (Combustible)

IV-HT

Heavy Timber (Combustible)

V-A

Protected Wood Frame (Combustible)

V-B

Unprotected Wood Frame (Combustible)

Prior to 2014 Code Construction Classifications

Class

Short Description

I-A

4-Hour Protected (Non-Combustible)

I-B

3-Hour Protected (Non-Combustible)

I-C

2-Hour Protected (Non-Combustible)

I-D

1-Hour Protected (Non-Combustible)

I-E

Unprotected (Non-Combustible)

II-A

Heavy Timber (Combustible)

II-B

Protected Wood Joist (Combustible)

II-C

Unprotected Wood Joist (Combustible)

II-D

Protected Wood Frame (Combustible)

II-E

Unprotected (Combustible)

1

Fireproof Structures (Old Code)

2

Fire-protected Structures (Old Code)

3

Non-fireproofed Structures (Old Code)

4

Wood Frame Structures (Old Code)

5

Metal Structures (Old Code)

6

Heavy Timber Structures (Old Code)

Building Occupancy Classifications

2014 Code Building Occupancy Designations

2014 Class

Short Description

1968 Class Equivalents(s)

A-1

Assembly (Theaters, Concert Halls): With fixed seating, intended for production and viewing of the performance arts or motion pictures.

F-1a

A-2

Assembly (Eating and Drinking – Cabaret): Where persons assemble for the consumption of food or drink in any room, place or space in which any musical entertainment, singing, dancing or other similar amusement is permitted.

F-4

Assembly (Eating and Drinking – Not a Cabaret): Where persons assemble for the consumption of food or drink in any room, place or space in which any musical entertainment, singing, dancing or other similar amusement is notpermitted.

A-3

Assembly (Other): Worship, recreation or amusement (physically active), and other assembly uses not classified elsewhere in Group A.

F-3, F-1b, F-4

A-4

Assembly (Indoor Sporting Events with Spectators): Indoor sporting events with spectator seating.

F-1b

A-5

Assembly (Outdoors): Participation in or viewing outdoor activities.

F-2

B

Business: Occupied for transacting business; for rendering professional services; or for performing other commercial services that may incidentally involve the storage of limited quantities of stock of goods for office use or purposes.

E

E

Educational: When persons occupy them for instruction or other educational purposes.

G

F-1

Factory and Industrial (Moderate Hazard): Used for fabricating, assembling, manufacturing, or processing products, materials, or energy and representing a moderated hazard due to the extent and nature of such operations, or to the materials involved.

D-1

F-2

Factory and Industrial (Low Hazard): Used for fabricating, assembling, manufacturing, or processing products, materials, or energy and representing a low hazard due to the extent and nature of such operations, or to the materials involved.

D-2

H-1

High Hazard (Explosive Detonation): Used for storing, manufacturing, or processing materials or energy that present a detonation hazard.

A

H-2

High Hazard (Accelerated Burning): Used for storing, manufacturing, or processing materials or energy where uses present a deflagration hazard or a hazard from accelerated burning.

A

H-3

High Hazard (Readily Supports Combustion): Used for storing, manufacturing, or energy that readily support combustion or present a physical hazard.

A

H-4

High Hazard (Health): Used for storing, manufacturing, or processing materials or energy that are health hazards.

None

H-5

High Hazard (Semiconductors): Used for storing, manufacturing, or processing semiconductor fabrication facilities using hazardous production materials (HPM) in excess of the permitted aggregate quantity.

D-1

I-1

Institutional (Assisted Living): Housing persons, on 24-hour basis, capable of self-preservation and responding to an emergency situation without physical assistance from staff.

J-2

I-2

Institutional (Incapacitated): Medical, surgical, nursing or custodial care, on a 24-hour basis, of more than 3 persons, who are not capable of self-preservation or responding to an emergency situation without physical assistance from staff.

H-2

I-3

Institutional (Restrained): More than 5 persons who are detained under restraint or security reasons.

H-1

I-4

Institutional (Daytime Custodial Care): Day care facilities, occupied by persons of any age who receive custodial care (without overnight) by individuals other than parents, guardians, or relatives in a place other than at the home.

H-2

M

Mercantile: Used for display and sales of goods accessible to public inspection.

C

R-1

Residential (Hotels, Dormitories, Congregate Living): Occupied transiently (for less than one month).

J-1

R-2

Residential (Apartment Houses): More than 2 dwelling units on a long-term basis (for a month or more).

J-2

R-3

Residential (1 and 2 Family Houses): Not more than 2 apartments on a long-term basis (for a month or more).

J-3

S-1

Storage (Moderate Hazard): Moderate-hazard storage occupancy for any flammable or combustible materials.

B-1

S-2

Storage (Low Hazard): Low-hazard storage occupancy for non- combustible materials.

B-2

U

Utility and Miscellaneous: Structures of an accessory character, or not classified in any specific occupancy.

K

Prior to 2008 Code Building Occupancy Designations

Class

Short Description

A

High Hazard: Used for storing, manufacturing, or processing potentially explosive products or materials, or highly-combustible or highly flammable products or materials that is likely to burn with extreme rapidity.

B-1

Storage (Moderate Hazard): Used primarily for storing any flammable or combustible materials that is likely to permit the development and propagation of fire with moderate rapidity.

B-2

Storage (Low Hazard): Used for storing noncombustible materials and materials that does not ordinarily burn rapidly.

C

Mercantile: Used for display and sales of goods accessible to public inspection.

D-1

Industrials (Moderate Hazard): Used for fabricating, assembling, manufacturing, or processing products, materials, or energy and representing a moderate hazard due to the extent and nature of such operations, or to the materials involved.

D-2

Industrials (Low Hazard): Used for fabricating, assembling, manufacturing, or processing products, materials, or energy and representing a low hazard due to the extent and nature of such operations, or to the materials involved.

E

Business: Occupied for transacting business; for rendering professional services; or for performing other commercial services that may incidentally involve the storage of limited quantities of stocks of goods for office use or purposes.

F-1a

Assembly (Theaters): Buildings in which the person assembled compromise a seated or otherwise passive audience to a performance or presentation, and have their attention focused in a common direction or at a common subjection, and in which scenery and scenic elements are used.

F-1b

Assembly (Churches, Concert Halls): Buildings in which the persons assembled compromise a seated or otherwise passive audience to a performance or presentation, and have their attention focused in a common direction or at a common subject, and in which scenery and scenic elements are not used.

F-2

Assembly (Outdoors): Includes all outdoor structures and spaces.

F-3

Assembly (Museums): Where the persons assembled are physically active and do not have a common center of attention.

F-4

Assembly (Eating and Drinking – Cabaret): Any room, place or space in which any musical entertainment, singing, dancing or other similar amusement is permitted.

Assembly (Eating and Drinking – Not a Cabaret): Where persons assemble for the consumption of food or drink

G

Education: When persons occupy them for instruction or other educational purposes.

H-1

Institutional (Restrained): Used for the detention of persons under restraint.

H-2

Institutional (Incapacitated): Used for the care or treatment persons with physical limitations because of health or age.

J-1

Residential (Hotels): Primarily occupied for the shelter and sleeping accommodation of individuals on a day-to-day or week-to-week basis (e.g. hotels, motels, lodging houses, rooming houses.)

J-2

Residential (Apartment Houses): Having three or more dwelling units that are primarily occupied for the shelter and sleeping accommodation of individuals on a month-to-month or longer-term basis (e.g. apartment houses, apartment hotels, rooming houses).

J-2

3-Family Dwelling: Having more dwellings that are primarily occupied for shelter and sleeping accommodation of individuals.

J-3

Residential (1 & 2 Family House): Occupied as one-family or two-family dwellings, or as convents or rectories.

K

Miscellaneous: Having a temporary character, and minor occupancies not classified in any other specific occupancy group (e.g. sheds, fences, signs).

PUB

Old Code – Public Buildings: Only applicable to buildings built before 1968. Structures in which persons congregate for civic, political, educational, religious or recreational purposes, or in which are harbored to receive medical treatment, or are detained by reason of public duty.

RES

Old Code – Residence Buildings: Only applicable buildings built before 1968. Structures in which sleeping accommodations are provided, except such as may for other reasons be classed as public buildings.

COM

Old Code – Commercial Buildings: Only applicable to buildings built before 1968. Structures which are not public buildings or residence buildings, including among others, office buildings, salesrooms (stores), markets, warehouses, and restaurants.

Multiple Dwelling Classifications (MDL)

Class A

Class B

Description

OL

 

Old Law Tenement: Originally erected as a multiple dwelling in accordance with the laws in effect prior to April 12, 1901 and recorded as OL in the Tenement House Department (now Department of Housing Preservation and Development) before April18, 1929. OLs comply with MDL Article 7.

OLSR

 

Old Law Tenement, Single Room: Old law tenements that contain units converted to single room occupancy pursuant to MDL § 248.

JAR

 

Joint Artist In Residence: Containing DUs that are classified as a ‘joint living work quarters for artists’ under Zoning Resolution § 12-10.

HAEA

HAEB

Hereafter Erected: Originally erected as a multiple dwelling in accordance with the laws in effect after January 1, 1929, whether old Code (pre-1968) or new Code (post 1968). This includes all newly constructed multiple dwellings (3 dwelling units (DUs) or more).

  • Also included are buildings originally erected as other than HAEA/HAEB, subsequently altered under the old Code to comply with NYS Multiple Dwelling Law (MDL) Article 3 and Article 4 or 5.
  • Also included are buildings originally erected as other than HAEA/HAEB, subsequently altered under the new Code to comply with all new Code requirements for J-2.

HCA

HCB

Heretofore Converted: Originally erected as a one- or two-family dwelling, and converted prior to April 18, 1929 to a multiple dwelling, and classified as a converted dwelling as per MDL § 4.10. HCAs and HCBs comply with MDL Article 6.

HACA

HACB

Hereafter Converted: Originally erected as a one- or two-family dwelling in accordance with the laws in effect prior to December 6, 1968, and converted after April 18, 1929 to a multiple dwelling in accordance with such laws, and classified  as a converted  dwelling  as per MDL § 4.10. HACAs and HACBs comply with MDL Article 6. If the original date of construction of the building is prior to April 18, 1929, then the stringent provisions of MDL§ 170-a do not apply. If the original date of construction of the building is after April 18, 1929, then the stringent provisions of MDL § 170-A apply.

CAA

 

Commercial Altered: Originally erected as a nonresidential building in accordance with the laws in effect prior to December 6, 1968, and used for one or more of the nonresidential purposes enumerated in MDL § 277 prior to January 1, 1977, and subsequently converted to a multiple dwelling in compliance with the old Code and MDL Article 7-B.

COL

 

Converted Old Law: A tenement recorded as such in the  Department of Housing Preservation and Development.

CNL

 

Converted New Law: A tenement recorded as such in the Department of Housing Preservation and Development.

NLSR

 

New Law Tenement, Single Room: New law tenements that contain units converted to single room occupancy pursuant to MDL § 248.

NL

 

New Law Tenement: Originally erected as a multiple dwelling in accordance with the laws in effect after April 12, 1901 and prior to April 18, 1929 and recorded as NL in the Tenement House Department (now NYC Department of Housing Preservation and Development) before April 18, 1929. NLs comply with MDL Article 7.

 

LH

Lodging House: Erected in accordance with the laws in effect prior to December 6,1968 as a lodging house, and subsequently maintained or altered in accordance with MDL § 66. These buildings typically have open plan rooms with many beds serving a transient population.

HEXA

HEXB

Heretofore Erected Existing: Erected in accordance with the laws in effect prior to January 1, 1929 as an apartment hotel or a hotel, and subsequently maintained or altered in accordance with MDL § 67. At the time of construction, they were exempt from the Tenement House Act (now found in MDL Article 7), at that time needing to comply only with the less stringent Building Code. However, in 1929, the MDL classified them as multiple dwellings.

 

Y

Y-Type: A class B multiple dwelling recorded as such in the Department of Housing Preservation and Development.