Each of the occupancy groupings is used to assess the degree to which the features contained in the core chapters of NFPA 101 need to be combined to achieve the minimum level of life safety necessary for an occupancy. Correct classification of the occupancy is extremely important, because the Code requirements differ for each type of occupancy. Improper classification might result in an inadequate level of life safety or overspending on non required items.
Assembly occupancies generally contain large numbers of people who are unfamiliar with the space and are, therefore, subject to indecision regarding the best means of egress in an emergency.
Educational occupancies primarily include the large numbers of young people found in school buildings.
Day-care occupancies contain both young and adult clients who are under the supervision of adults other than their relatives or legal guardians. In cases where day-care occupancies cater to preschool-age children, the occupants might need to be carried out of the facility during evacuation.
Health care occupancies are characterized by occupants who are incapable of self-preservation and occupy the occupancy on an inpatient basis. For occupancies that provide health care services on an outpatient basis, see the description that follows on ambulatory health care occupancies. In a health care occupancy, the occupants may not be able to use exits, regardless of the number of exits provided. Occupants might be immobile, connected to monitoring equipment, debilitated, or recovering from surgery; or they might be disabled in some other way. The Code, in this instance, calls for a defend-in-place design strategy that uses horizontal movement and compartmentation. It recognizes that the occupants are to be provided enough protection to enable them to survive the fire by remaining in the structure, at least temporarily.
Ambulatory health care
Ambulatory health care occupancies are similar to health care occupancies in that the occupants are generally incapable of self-preservation, but, unlike health care occupancies, the patients receive medical care on an outpatient basis. In many cases, the treatment causes the patient to be incapable of self-preservation. In other cases, a procedure, such as administering general anesthesia that is needed in conjunction with a treatment, renders the patient incapable of self-preservation. In yet other cases, the patient arrives at the ambulatory health care facility incapable of self-preservation due to an injury or illness, as is common in an emergency or urgent care outpatient facility. The ambulatory health care occupancy operates on an outpatient basis, so no individual patient occupies the building for a period of 24 hours or more.
Detention and correctional
Detention and correctional occupancies, as in the case of health care occupancies, house occupants who are incapable of self-preservation. In a detention and correctional occupancy, however, the incapability for self-preservation is due to the security imposed on the occupants. Because doors are not unlocked to allow free egress to the public way, the defend-in-place design strategy is used.
Residential occupancies are characterized by occupants who are asleep for a portion of the time they occupy the building. The sleeping that takes place is for normal restorative rest, as opposed to the sleeping that takes place in a hospital or residential board and care facility where caretakers are present. Sleeping occupants might be unaware of an incipient fire and might be trapped before egress can occur, thus creating a need for early warning smoke alarms. This occupancy group is further divided into one- and two-family dwellings, lodging or rooming houses, hotels and dormitories, and apartment buildings. Each occupancy in the group has characteristic needs that differ from the others. For this reason, separate occupancy-specific provisions address each of these subgroups.
Residential board and care
Residential board and care occupancies, as in the case of residential occupancies, provide sleeping accommodations. However, the residents also receive personal care services by caretakers who live with the residents. Personal care includes assistance with many of the activities of daily living, such as bathing and dressing. Personal care does not include medical care.
Mercantile occupancies, as in the case of assembly occupancies, are characterized by large numbers of people who gather in a space that is relatively unfamiliar to them. In addition, mercantile occupancies often contain sizable quantities of combustible contents and use circuitous egress paths that are deliberately arranged to force occupants to travel around displays of materials that are available for sale.
Business occupancies generally have a lower occupant density than mercantile occupancies, and the occupants are usually more familiar with their surroundings. However, confusing and indirect egress paths are often developed due to office layouts and the arrangement of tenant spaces. The Code requirements for such occupancies address the needs of visitors unfamiliar with the building.
Industrial occupancies expose occupants to a wide range of processes and materials of varying hazard. Special-purpose industrial occupancies, which are characterized by large installations of equipment that dominate the space, are addressed separately from general-purpose industrial facilities, which have higher densities of human occupancy.
Storage occupancies are characterized by relatively low human occupancy in comparison to building size and by varied hazards associated with the materials stored.