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IBC Chapter 3 — Use and Occupancy Classification

Updated Mar 25, 2026
Classification of buildings by occupancy group: Assembly (A), Business (B), Educational (E), Factory (F), High-Hazard (H), Institutional (I), Mercantile (M), Residential (R), Storage (S), Utility (U).

Buildings and structures shall be classified by their use or the character of their occupancy into one of the occupancy groups listed below. Assembly Group A: gathering of persons for civic, social, or religious functions, recreation, food/drink, or similar activities. A-1 fixed seating for performing arts. A-2 food/drink. A-3 worship, recreation. A-4 indoor sporting. A-5 outdoor. Business Group B: office, professional, or service-type transactions. Educational Group E: grades K-12 and day care >5 children. Factory Group F: assembling, disassembling, fabricating, finishing, manufacturing, packaging, repair, or processing. F-1 moderate hazard. F-2 low hazard. High-Hazard Group H: manufacturing, processing, generation, or storage of materials that constitute a physical or health hazard. Institutional Group I: care or supervision of occupants. I-1 supervised residential. I-2 medical care. I-3 restrained. I-4 day care. Mercantile Group M: display and sale of merchandise. Residential Group R: sleeping accommodation not classified as I. R-1 transient. R-2 permanent (3+ units). R-3 one/two family. R-4 assisted living. Storage Group S: storage not classified as H. S-1 moderate hazard. S-2 low hazard. Utility Group U: accessory character, miscellaneous structures.

TAGS
IBCoccupancyuse-groupclassificationbuilding-type
DETAILS
code year
2024
code system
IBC
code section
Chapter 3
occupancy groups
["A","B","E","F","H","I","M","R","S","U"]
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