Chapter 3 Occupancy Classification and Use

The provisions of this chapter shall control the classification of all buildings and structures as to occupancy and use. Different classifications of occupancy and use represent varying levels of hazard and risk to building occupants and adjacent properties.

Occupancy classification is the formal designation of the primary purpose of the building, structure or portion thereof. Structures shall be classified into one or more of the occupancy groups specified in this section based on the nature of the hazards and risks to building occupants generally associated with the intended purpose of the building or structure. An area, room or space that is intended to be occupied at different times for different purposes shall comply with all applicable requirements associated with such potential multipurpose. Structures containing multiple occupancy groups shall comply with Section 508. Where a structure is proposed for a purpose that is not specified in this section, such structure shall be classified in the occupancy it most nearly resembles based on the fire safety and relative hazard. Occupiable roofs shall be classified in the group that the occupancy most nearly resembles, according to the fire safety and relative hazard, and shall comply with Section 503.1.4.

1. 1.

   Assembly (see Section 303): Groups A-1, A-2, A-3, A-4 and A-5.

2. 2.

   Business (see Section 304): Group B.

3. 3.

   Educational (see Section 305): Group E.

4. 4.

   Factory and Industrial (see Section 306): Groups F-1 and F-2.

5. 5.

   High Hazard (see Section 307): Groups H-1, H-2, H-3, H-4 and H-5.

6. 6.

   Institutional (see Section 308): Groups I-1, I-2, I-3 and I-4.

7. 7.

   Mercantile (see Section 309): Group M.

8. 8.

   Residential (see Section 310): Groups R-1, R-2, R-3 and R-4.

9. 9.

   Storage (see Section 311): Groups S-1 and S-2.

10. 10.

    Utility and Miscellaneous (see Section 312): Group U.

Occupancy groups contain subordinate uses having similar hazards and risks to building occupants. Uses include, but are not limited to, those functional designations specified within the occupancy group descriptions in Section 302.1. Certain uses require specific limitations and controls in accordance with the provisions of Chapter 4 and elsewhere in this code.

Assembly Group A occupancy includes, among others, the use of a building or structure, or a portion thereof, for the gathering of persons for purposes such as civic, social or religious functions; recreation, food or drink consumption or awaiting transportation.

Group A-1 occupancy includes assembly uses, usually with fixed seating, intended for the production and viewing of the performing arts or motion pictures, including but not limited to:

• Motion picture theaters

• Symphony and concert halls

• Television and radio studios admitting an audience

• Theaters

Group A-2 occupancy includes assembly uses intended for food and/or drink consumption, including but not limited to:

• Banquet halls

• Casinos (gaming areas)

• Nightclubs

• Restaurants, cafeterias and similar dining facilities (including associated commercial kitchens)

• Taverns and bars

Group A-3 occupancy includes assembly uses intended for worship, recreation or amusement and other assembly uses not classified elsewhere in Group A, including but not limited to:

• Amusement arcades

• Art galleries

• Bowling alleys

• Community halls

• Courtrooms

• Dance halls (not including food or drink consumption)

• Exhibition halls

• Funeral parlors

• Greenhouses for the conservation and exhibition of plants that provide public access

• Gymnasiums (without spectator seating)

• Indoor swimming pools (without spectator seating)

• Indoor tennis courts (without spectator seating)

• Lecture halls

• Libraries

• Museums

• Places of religious worship

• Pool and billiard parlors

• Waiting areas in transportation terminals

Group A-4 occupancy includes assembly uses intended for viewing of indoor sporting events and activities with spectator seating, including but not limited to:

• Arenas

• Skating rinks

• Swimming pools

• Tennis courts

Group A-5 occupancy includes assembly uses intended for participation in or viewing outdoor activities, including but not limited to:

• Amusement park structures

• Bleachers

• Grandstands

• Stadiums

Business Group B occupancy includes, among others, the use of a building or structure, or a portion thereof, for office, professional or service-type transactions, including storage of records and accounts. Business occupancies shall include, but not be limited to, the following:

• Airport traffic control towers

• Ambulatory care facilities

• Animal hospitals, kennels and pounds

• Banks

• Barber and beauty shops

• Car wash

• Civic administration

• Clinic, outpatient

• Dry cleaning and laundries: pick-up and delivery stations and self-service

• Educational occupancies for students above the 12th grade including higher education laboratories

• Electronic data entry

• Food processing establishments and commercial kitchens not associated with restaurants, cafeterias and similar dining facilities not more than 2,500 square feet (232 m²) in area

• Laboratories: testing and research

• Lithium-ion or lithium metal battery testing, research and development

• Motor vehicle showrooms

• Post offices

• Print shops

• Professional services (architects, attorneys, dentists, physicians, engineers, etc.)

• Radio and television stations

• Telephone exchanges

• Training and skill development not in a school or academic program (this shall include, but not be limited to, tutoring centers, martial arts studios, gymnastics and similar uses regardless of the ages served, and where not classified as a Group A occupancy)

Airport traffic control towers shall comply with Section 412.2.

Ambulatory care facilities shall comply with Section 422.

Higher education laboratories shall comply with Section 428.

Educational Group E occupancy includes, among others, the use of a building or structure, or a portion thereof, by six or more persons at any one time for educational purposes through the 12th grade.

This group includes buildings and structures or portions thereof occupied by more than five children older than 2 1/2 years of age who receive educational, supervision or personal care services for fewer than 24 hours per day.

Storm shelters shall be provided for Group E occupancies where required by Section 423.5.

Factory Industrial Group F occupancy includes, among others, the use of a building or structure, or a portion thereof, for assembling, disassembling, fabricating, finishing, manufacturing, packaging, repair or processing operations that are not classified as a Group H hazardous or Group S storage occupancy.

Factory industrial uses that are not classified as Factory Industrial F-2 Low Hazard shall be classified as F-1 Moderate Hazard and shall include, but not be limited to, the following:

• Aircraft (manufacturing, not to include repair)

• Appliances

• Athletic equipment

• Automobiles and other motor vehicles

• Bakeries

• Beverages: over 20 percent alcohol content

• Bicycles

• Boats

• Brooms or brushes

• Business machines

• Cameras and photo equipment

• Canvas or similar fabric

• Carpets and rugs (includes cleaning)

• Clothing

• Construction and agricultural machinery

• Disinfectants

• Dry cleaning and dyeing

• Electric generation plants

• Electronics

• Energy storage systems (ESS) in dedicated use buildings

• Energy storage systems (ESS) and equipment containing lithium-ion or lithium metal batteries

• Engines (including rebuilding)

• Food processing establishments and commercial kitchens not associated with restaurants, cafeterias and similar dining facilities more than 2,500 square feet (232 m²) in area

• Furniture

• Hemp products

• Jute products

• Laundries

• Leather products

• Lithium-ion batteries

• Machinery

• Metals

• Millwork (sash and door)

• Motion pictures and television filming (without spectators)

• Musical instruments

• Optical goods

• Paper mills or products

• Photographic film

• Plastic products

• Printing or publishing

• Recreational vehicles

• Refuse incineration

• Shoes

• Soaps and detergents

• Textiles

• Tobacco

• Trailers

• Upholstering

• Vehicles powered by lithium-ion or lithium metal batteries

• Water/sewer treatment facilities

• Wood; distillation

• Woodworking (cabinet)

Factory industrial uses that involve the fabrication or manufacturing of noncombustible materials that during finishing, packing or processing do not involve a significant fire hazard shall be classified as Group F-2 occupancies and shall include, but not be limited to, the following:

• Beverages: up to and including 20 percent alcohol content

• Brick and masonry

• Ceramic products

• Foundries

• Glass products

• Gypsum

• Ice

• Metal products (fabrication and assembly)

High-hazard Group H occupancy includes, among others, the use of a building or structure, or a portion thereof, that involves the manufacturing, processing, generation or storage of materials that constitute a physical or health hazard in quantities in excess of those allowed in control areas complying with Section 414, based on the maximum allowable quantity limits for control areas set forth in Tables 307.1(1) and 307.1(2). Hazardous occupancies are classified in Groups H-1, H-2, H-3, H-4 and H-5 and shall be in accordance with this section, the requirements of Section 415 and the International Fire Code. Hazardous materials stored or used on top of roofs or canopies shall be classified as rooftop storage or use and shall comply with the International Fire Code.

Hazardous materials in any quantity shall conform to the requirements of this code, including Section 414, and the International Fire Code.

Buildings and structures containing materials that pose a detonation hazard shall be classified as Group H-1. Such materials shall include, but not be limited to, the following:

• Detonable pyrophoric materials

• Explosives:

  • Division 1.1

  • Division 1.2

  • Division 1.3

  • Division 1.4

  • Division 1.5

  • Division 1.6

• Organic peroxides, unclassified detonable

• Oxidizers, Class 4

• Unstable (reactive) materials, Class 3 detonable and Class 4

Buildings and structures containing materials that pose a deflagration hazard or a hazard from accelerated burning shall be classified as Group H-2. Such materials shall include, but not be limited to, the following:

• Class I, II or IIIA flammable or combustible liquids that are used or stored in normally open containers or systems, or in closed containers or systems pressurized at more than 15 pounds per square inch gauge (103.4 kPa).

• Combustible dusts where manufactured, generated or used in such a manner that the concentration and conditions create a fire or explosion hazard based on information prepared in accordance with Section 414.1.3.

• Cryogenic fluids, flammable.

• Category 1A flammable gases.

• Category 1B flammable gases having a burning velocity greater than 3.9 inches per second (10 cm/s)

• Organic peroxides, Class I.

• Oxidizers, Class 3, that are used or stored in normally open containers or systems, or in closed containers or systems pressurized at more than 15 pounds per square inch gauge (103 kPa).

• Pyrophoric liquids, solids and gases, nondetonable.

• Unstable (reactive) materials, Class 3, nondetonable.

• Water-reactive materials, Class 3.

Buildings and structures containing materials that readily support combustion or that pose a physical hazard shall be classified as Group H-3. Such materials shall include, but not be limited to, the following:

• Class I, II or IIIA flammable or combustible liquids that are used or stored in normally closed containers or systems pressurized at 15 pounds per square inch gauge (103.4 kPa) or less

• Combustible fibers, other than densely packed baled cotton, where manufactured, generated or used in such a manner that the concentration and conditions create a fire or explosion hazard based on information prepared in accordance with Section 414.1.3

• Consumer fireworks, 1.4G (Class C, Common)

• Cryogenic fluids, oxidizing

• Category 1B flammable gases having a burning velocity of 3.9 inches per second (10 cm/s) or less

• Flammable solids

• Organic peroxides, Class II and III

• Oxidizers, Class 2

• Oxidizers, Class 3, that are used or stored in normally closed containers or systems pressurized at 15 pounds per square inch gauge (103 kPa) or less

• Oxidizing gases

• Unstable (reactive) materials, Class 2

• Water-reactive materials, Class 2

Buildings and structures containing materials that are health hazards shall be classified as Group H-4. Such materials shall include, but not be limited to, the following:

• Corrosives

• Highly toxic materials

• Toxic materials

Semiconductor fabrication facilities and comparable research and development areas in which hazardous production materials (HPM) are used and the aggregate quantity of materials is in excess of those specified in Tables 307.1(1) and 307.1(2) shall be classified as Group H-5. Such facilities and areas shall be designed and constructed in accordance with Section 415.11.

Buildings and structures containing a material or materials representing hazards that are classified in one or more of Groups H-1, H-2, H-3 and H-4 shall conform to the code requirements for each of the occupancies so classified.

Institutional Group I occupancy includes, among others, the use of a building or structure, or a portion thereof, in which care or supervision is provided to persons who are or are incapable of self-preservation without physical assistance or in which persons are detained for penal or correctional purposes or in which the liberty of the occupants is restricted. Institutional occupancies shall be classified as Group I-1, I-2, I-3 or I-4.

Institutional Group I-1 occupancy shall include buildings, structures or portions thereof for more than 16 persons, excluding staff, who reside on a 24-hour basis in a supervised environment and receive custodial care. Buildings of Group I-1 shall be classified as one of the occupancy conditions specified in Section 308.2.1 or 308.2.2 and shall comply with Section 420. This group shall include, but not be limited to, the following:

• Alcohol and drug centers

• Assisted living facilities

• Congregate care facilities

• Group homes

• Halfway houses

• Residential board and care facilities

• Social rehabilitation facilities

Institutional Group I-2 occupancy shall include buildings and structures used for medical care on a 24-hour basis for more than five persons who are incapable of self-preservation. This group shall include, but not be limited to, the following:

• Foster care facilities

• Detoxification facilities

• Hospitals

• Nursing homes

• Psychiatric hospitals

Institutional Group I-3 occupancy shall include buildings and structures that are inhabited by more than five persons who are under restraint or security. A Group I-3 facility is occupied by persons who are generally incapable of self-preservation due to security measures not under the occupants’ control. This group shall include, but not be limited to, the following:

• Correctional centers

• Detention centers

• Jails

• Prerelease centers

• Prisons

• Reformatories

Buildings of Group I-3 shall be classified as one of the occupancy conditions specified in Sections 308.4.1 through 308.4.5 and shall comply with Section 408.

Institutional Group I-4 occupancy shall include buildings and structures occupied by more than five persons of any age who receive custodial care for fewer than 24 hours per day by persons other than parents or guardians; relatives by blood, marriage or adoption; and in a place other than the home of the person cared for. This group shall include, but not be limited to, the following:

• Adult day care

• Child day care

Mercantile Group M occupancy includes, among others, the use of a building or structure or a portion thereof for the display and sale of merchandise, and involves stocks of goods, wares or merchandise incidental to such purposes and where the public has access. Mercantile occupancies shall include, but not be limited to, the following:

• Department stores

• Drug stores

• Greenhouses for display and sale of plants that provide public access

• Markets

• Motor fuel-dispensing facilities

• Retail or wholesale stores

• Sales rooms

The aggregate quantity of nonflammable solid and nonflammable or noncombustible liquid hazardous materials stored or displayed in a single control area of a Group M occupancy shall not exceed the quantities in Table 414.2.5.1.

Motor fuel-dispensing facilities shall comply with Section 406.7.

Residential Group R includes, among others, the use of a building or structure, or a portion thereof, for sleeping purposes when not classified as an Institutional Group I or when not regulated by the International Residential Code. Group R occupancies not constructed in accordance with the International Residential Code as permitted by Sections 310.4.1 and 310.4.2 shall comply with Section 420.

Residential Group R-1 occupancies containing sleeping units or more than two dwelling units where the occupants are primarily transient in nature, including:

• Boarding houses (transient) with more than 10 occupants

• Congregate living facilities (transient) with more than 10 occupants

• Hotels (transient)

• Motels (transient)

• Lodging houses with more than five guestrooms

Residential Group R-2 occupancies containing sleeping units or more than two dwelling units where the occupants are primarily permanent in nature, including:

• Apartment houses

• Congregate living facilities (nontransient) with more than 16 occupants

  • Boarding houses (nontransient)

  • Convents

  • Dormitories

  • Emergency services living quarters

  • Fraternities and sororities

  • Monasteries

• Hotels (nontransient) with more than five guestrooms

• Live/work units

• Motels (nontransient) with more than five guestrooms

• Vacation timeshare properties

Residential Group R-3 occupancies where the occupants are primarily permanent in nature and not classified as Group R-1, R-2, R-4 or I, including:

• Buildings that do not contain more than two dwelling units

• Care facilities that provide accommodations for five or fewer persons receiving care

• Congregate living facilities (nontransient) with 16 or fewer occupants

  • Boarding houses (nontransient)

  • Convents

  • Dormitories

  • Emergency services living quarters

  • Fraternities and sororities

  • Monasteries

• Congregate living facilities (transient) with 10 or fewer occupants

  • Boarding houses (transient)

• Lodging houses with five or fewer guestrooms

• Hotels (nontransient) with five or fewer guestrooms

• Motels (nontransient) with five or fewer guestrooms

Residential Group R-4 occupancy shall include buildings, structures or portions thereof for more than five but not more than 16 persons, excluding staff, who reside on a 24-hour basis in a supervised residential environment and receive custodial care. Buildings of Group R-4 shall be classified as one of the occupancy conditions specified in Section 310.5.1 or 310.5.2. This group shall include, but not be limited to, the following:

• Alcohol and drug centers

• Assisted living facilities

• Congregate care facilities

• Group homes

• Halfway houses

• Residential board and care facilities

• Social rehabilitation facilities

Group R-4 occupancies shall meet the requirements for construction as defined for Group R-3, except as otherwise provided for in this code.

Storage Group S occupancy includes, among others, the use of a building or structure, or a portion thereof, for storage that is not classified as a hazardous occupancy.

Storage Group S-1 occupancies are buildings occupied for storage uses that are not classified as Group S-2, including, but not limited to, storage of the following:

• Aerosol products, Levels 2 and 3, aerosol cooking spray, plastic aerosol 3 (PA3)

• Aircraft hangar (storage and repair)

• Bags: cloth, burlap and paper

• Bamboos and rattan

• Baskets

• Belting: canvas and leather

• Beverages over 20 percent alcohol content

• Books and paper in rolls or packs

• Boots and shoes

• Buttons, including cloth covered, pearl or bone

• Cardboard and cardboard boxes

• Clothing, woolen wearing apparel

• Cordage

• Dry boat storage (indoor)

• Furniture

• Furs

• Glues, mucilage, pastes and size

• Grains

• Horns and combs, other than celluloid

• Leather

• Linoleum

• Lithium-ion or lithium metal batteries

• Lumber

• Motor vehicle repair garages complying with the maximum allowable quantities of hazardous materials specified in Table 307.1(1) (see Section 406.8)

• Photo engravings

• Resilient flooring

• Self-service storage facility (mini-storage)

• Silks

• Soaps

• Sugar

• Tires, bulk storage of

• Tobacco, cigars, cigarettes and snuff

• Upholstery and mattresses

• Vehicle repair garages for vehicles powered by lithium-ion or lithium metal batteries

• Wax candles

Storage Group S-2 occupancies include, among others, buildings used for the storage of noncombustible materials such as products on wood pallets or in paper cartons with or without single thickness divisions; or in paper wrappings. Such products are permitted to have a negligible amount of plastic trim, such as knobs, handles or film wrapping. Group S-2 storage uses shall include, but not be limited to, storage of the following:

• Asbestos

• Beverages up to and including 20 percent alcohol

• Cement in bags

• Chalk and crayons

• Dairy products in nonwaxed coated paper containers

• Dry cell batteries

• Electrical coils

• Electrical motors

• Empty cans

• Food products

• Foods in noncombustible containers

• Fresh fruits and vegetables in nonplastic trays or containers

• Frozen foods

• Glass

• Glass bottles, empty or filled with noncombustible liquids

• Gypsum board

• Inert pigments

• Ivory

• Meats

• Metal cabinets

• Metal desks with plastic tops and trim

• Metal parts

• Metals

• Mirrors

• Oil-filled and other types of distribution transformers

• Public parking garages, open or enclosed

• Porcelain and pottery

• Stoves

• Talc and soapstones

• Washers and dryers

Buildings and structures of an accessory character and miscellaneous structures not classified in any specific occupancy shall be constructed, equipped and maintained to conform to the requirements of this code commensurate with the fire and life hazard incidental to their occupancy. Group U shall include, but not be limited to, the following:

• Agricultural buildings

• Aircraft hangars, accessory to a one- or two-family residence (see Section 412.4)

• Barns

• Carports

• Communication equipment structures with a gross floor area of less than 1,500 square feet (139 m²)

• Fences more than 7 feet (2134 mm) in height

• Grain silos, accessory to a residential occupancy

• Livestock shelters

• Private garages

• Retaining walls

• Sheds

• Stables

• Tanks

• Towers

Private garages and carports shall comply with Section 406.3.

Aircraft hangars accessory to a one- or two-family residence shall comply with Section 412.4.