IBC Occupancy Classifications for Fire Alarm

Occupancy Classifications Based on the International Building Code

Occupancy classifications are broken down in the 2021 IBC or International Building Code Chapter 3 "Occupancy Classification and Use". These different groups are made up for different uses and structures.  As you guessed, each occupancy classification has its own fire alarm system requirements. These fire alarm requirements are found in the IFC or International Fire Code section 907.  Below is a simple breakdown of what each occupancy classification is used for.  We have also included links that will take you directly to the fire alarm requirements for each group.

Occupancy Groups

Assembly Group A Occupancy:  Uses intended for the gathering together of persons for the purposes such as civic, social or religious functions, recreation, food or drink consumption or awaiting transportation.  A room of less than 50 persons used for assembly but is accessory to a different occupancy shall be considered that different occupancy.  Assembly areas less than 750 s.f. which is accessory to a different occupancy is not considered assembly.  Assembly rooms which are accessory to Group E are not considered as Group A.  Religious education rooms and auditoriums with occupant loads less than 100 persons which are accessory to churches are considered A-3.  Note that a building or tenant space used or assembly purposes with an occupant load of less than 50 persons shall be classified as a Group B occupancy. A room or space for assembly purposes that is less than 750 square feet in area or accessory to another occupancy shall be classified as a group B occupancy or as part of that occupancy. Group A is divided into five sub groups as follows:

A-1: Assembly use. Usually with fixed seating, intended for production and viewing of the performing arts or motion pictures.
A-2: Uses intended for food and drink consumption.
A-3: Uses intended for worship, recreation or amusement and other assembly uses not otherwise classified.
A-4: Uses intended for viewing of indoor sporting events and activities with spectator seating.
A-5: Uses intended for participation in or viewing outdoor activities.

Click here to find out what fire alarm equipment is required for Group A Occupancy.

Business Group B Occupancy:  Assembly occupancies less than 50 persons and/or uses intended for office, professional or service type transactions, including storage of records and accounts.

Click here to find out what fire alarm equipment is required for Group B Occupancy.

Educational Group E Occupancy:  Uses intended by 6 or more persons at any time for educational purposes through the 12th grade.  Daycare uses for educational, supervision or personal care services for more than 6 children older than 2 years of age. Religious education rooms or auditoriums that have an occupant load of less than 100 per room or space shall be classified as Group A-3 occupancies.

Click here to find out what fire alarm equipment is required for Group E Occupancy.

Factory Industrial Group F Occupancy:  Uses intended for assembling, disassembling, fabricating, finishing, manufacturing, packaging, repair or processing operations that are not classified as Group H Hazardous or Group S Storage.  Group is divided into two sub groups.

Group F-1: Moderate Hazard
Group F-2: Low Hazard

Click here to find out what fire alarm equipment is required for Group F Occupancy.

High-Hazard Group H Occupancy:  Uses intended for manufacturing, processing, generation or storage of materials that constitute a physical or health hazard in quantities in excess of those allowed by code.  Group H is divided into 5 sub groups.

Group H-1: Detonation Hazard
Group H-2: Deflagration Hazard or Accelerated Burning
Group H-3: Materials that readily support combustion or pose a physical hazard.
Group H-4: Materials are health hazard
Group H-5: Semiconductor fabrication facilities and comparable R&D areas which HPM's are used.

Click here to find out what fire alarm equipment is required for Group H Occupancy.

Institutional Group I Occupancy:  Uses intended in which people are cared for or live in a supervised environment, having physical limitations because of health or age are harbored for medical treatment or other care or treatment or in which the liberty of the occupants is restricted.  Group I is divided into four sub groups.

Group I-1:  Houses more than 16 persons, on a 24 hour basis, who because of age, mental disability or other reasons, live in a supervised residential environment that provides personal care services.  The occupants are capable of responding to an emergency situation without physical assistance from staff.
Group I-2:  Used for medical, surgical, psychiatric, nursing or custodial care on a 24 hour basis of more than 5 persons who are not capable of self-preservation.  Less than five people shall be considered a Group R-3.
Group I-3:  Is inhabited by more than five persons who are under restraint or security and is occupied by persons who are generally incapable of self-preservation due to security measures not under the occupant's control.
Group I-4:  Includes buildings or structures occupied by more than 5 persons of any age who receive custodial care for fewer than 24 hours per day by persons other than parents or guardians. (Adult Day Care or Child Day Care).

Click here to find out what fire alarm equipment is required for Group I Occupancy.

Mercantile Group M Occupancy:  The use of a building or structure or a portion thereof for the display and sale of gods and involves stocks of goods. (Grocery Stores, Drug Stores, Markets, Retail Stores, etc.)

Click here to find out what fire alarm equipment is required for Group M Occupancy.

Residential Group R Occupancy:  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-1:  Residential use for occupants that are primarily transient in nature. (Hotel, Motel, Boarding Home (transient), etc.)
Group R-2:  Residential use for occupants that are primarily permanent in nature. (Apartments, Condos, etc.)
Group R-3:  Residential use for occupants that are primarily permanent in nature which does not classify as Group R-1, R-2, R-4 or I. Including Boarding Homes (non-transient), Convents, Dormitories, etc.
Group R-4:  Residential use for more than 5 but fewer than 16 occupants, excluding staff, who reside on a 24 hour basis in a supervised environment. (Half-Way House, Assisted Living Facilities, Alcohol and Drug Centers, Group Homes, etc.

Click here to find out what fire alarm equipment is required for Group R Occupancy.

Storage Group S Occupancy:  The use of a building or structure or a portion thereof, for storage not classified as a hazardous occupancy.

Group S-1:  Moderate Hazard storage of combustible items not classified as a hazardous occupancy Group H.
Group S-2:  Low Hazard storage of noncombustible items not classified as a hazardous occupancy Group H.

Utility and Miscellaneous Group U Occupancy:  The use of a building or structure or a portion thereof, not classified by any of the above occupancy groups. (Example: Barns, Livestock Shelters, Stables, Tanks, etc.)