Building occupancy classificationsrefer to categorizing structures based on their usage and are primarily used for building and fire code enforcement. They are usually defined by model building codes, and vary, somewhat, among them. Often, many of them are subdivided.
Assembly - places used for people gathering for entertainment, worship, and eating or drinking. Examples: churches, restaurants, theaters, and stadiums. Group A is divided into five sub groups:
Business - places where services are provided. Examples: banks, insurance agencies, government buildings, and doctor's offices.
Factory - places where goods are manufactured or repaired. Examples: factories and dry cleaners.
High-Hazard - places involving production or storage of very flammable or toxic materials. Includes places handling explosives and/or highly toxic materials.
Institutional - places where people are physically unable to leave without assistance. Examples: hospitals, nursing homes, and prisons. In some jurisdictions, Group I may be used to designate Industrial.
Mercantile - places where goods are displayed and sold. Examples: grocery stores, department stores, and gas stations.
Residential - places providing accommodations for overnight stay. Examples: houses, apartment buildings, hotels, and motels.
Storage - places where items are stored. Examples: warehouses and parking garages.
Utility and Miscellaneous - others. Examples: water towers, barns, towers.
Other Considerations
Many buildings may have multiple occupancies. These are referred to as "mixed occupancies" and the different parts will be required to meet the codes for those specific areas. An example of this is a shopping mall with underground parking. The shopping area itself is Group M, while the parking area would qualify as Group S. In places where more than one occupancy may apply, the stricter code is usually enforced. An example of this is a restaurant with seating under 50 which is not addressed in the code as either mercantile or business. Code enforcement officials will usually enforce the stricter side of the code.
