Description of Occupancies by Group and Division
| Group and Division | Section of UBC1997 | Description of Occupancy |
| A-1 | 303.1.1 | A building or portion of a building having an assembly room with an occupant load of 1,000 or more and legitimate stage. |
| A-2 | A building or portion of a building having an assembly room with an occupant load of less than 1,000 and a legitimate stage. | |
| A-2.1 | A building or portion of a building having an assembly room with an occupant load of 300 or more without a legitimate stage, including such building used for educational purposes and not classed as a Group E or Group B Occupancy. | |
| A-3 | Any building or portion of a building having an assembly room with an occupant load of less than 300 without a legitimates stage, including such buildings used for educational purposes and not classed as a Group E or Group B Occupancy. | |
| A-4 | Stadiums, reviewing stands and amusement park structures not included within other Group A Occupancies. | |
| B | 304.1 | A building or structure, or a portion thereof, for office, professional or service-type transactions, including storage of records and accounts; eating and drinking establishments with an occupant load of less than 50. |
| E-1 | 305.1 | Any building used for educational purposes through the 12th grade by 50 or more persons for more than 12 hours per week or four hours in any one day. |
| E-2 | Any building used for educational purposes through the 12th grade by less than 50 persons for more than 12 hours per week or four hours in any one day. | |
| E-3 | Any building or portion thereof used for day-care purposes for more than six persons. | |
| F-1 | 306.1 | Moderate-hazard factory and industrial occupancies include factory and industrial uses not classified as Group F. Division 2 Occupancies. |
| F-2 | Low-hazard factory and industrial occupancies include facilities producing noncombustible or non-explosove materials that during finishing, packing or processing do not involve a significant fire hazard. | |
| H-1 | 307.1 | Occuoancies with a quantity of material in the building in excess of those listed in Table 3-D that present a high explosion hazard as listed in Section 307.1.1. |
| H-2 | Occupancies with a quantity of material in the building in excess of those listed in Table 3-D that present a moderate explosion hazard of hazard from accelerated burning as listed in Section 307.1.1. | |
| H-3 | Occupancies with a quantity of material in the building in excess of those listed in Table 3-D that present a high fire or physical hazard as listed in Section 307.1.1. | |
| H-4 | Repair garages not classified as Group S, Division 3 Occupancies. | |
| H-5 | Aircraft repair hangars not classified as Group S, Division 5 Occupancies. | |
| H-6 | 307.1 and 307.11 | Semiconductor fabrication facilities and comparable research and development areas when the facilities in which hazardous production materials are used, and the aggregate quantity of material is in excess of those listed in Table 3-D or 3-E. |
| H-7 | 307.1 | Occupancies having quantities of materials in excess of those listed in Table 3-E that are health hazards as listed in Section 307.1.1. |
| I-1.1 | 308.1 | Nurseries for the full-time care of children under the age of six (each accommodating more than five children), hospitals, sanitariums, nursing homes with non-ambulatory patients and similar buildings (each accommodating more than five patients). |
| I-1.2 | Health-care centers for ambulatory patients receiving outpatient medical care which may render the patient incapable of unassisted self-preservation (each tenant space accommodating more than five such patients). | |
| I-2 | Nursing fomes for ambulatory patients, homes for children six years of age or over (each accommodating more than five persons). | |
| I-3 | Mental hospitals, mental sanitariums, jails, prisons, reformatories and building where personal liberties of inmates are similarly restrained. | |
| M | 309.1 | A building or structure, or a portion thereof, for the display and sale of merchandise, and involving stocks of goods, wares or merchandise, incidental to such purposes and accessible to the public. |
| R-1 | 310.1 | Hotels and apartment houses, congregate residences (each accommodating more than 10 persons). |
| R-3 | Dwellings, lodging houses, congregate residences (each accommodating 10 or fewer persons). | |
| S-1 | 311.1 | Moderate hazard storage occupancies including buildings or portions of building used for storage of combustible materials not classified as Group S, Division 2 or Group H Occuopancies. |
| S-2 | Low-hazard storage occupancies including building or portions of building used for storage of non-combustible materials. | |
| S-3 | Repair garages where work is limited to exchange of parts and maintenance not requiring open flame or welding, and parking garages not classified as Group S, Division 4 Occupancies. | |
| S-4 | Open parking garages. | |
| S-5 | Aircraft hangers and helistops. | |
| U-1 | 312.1 | Private garages, carports, sheds and agricultural buildings. |
| U-2 | Fences over 1829 mm (6 feet) high, tanks and towers. |