Chapter 3 — OCCUPANCY CLASSIFICATION AND USE
Section 310
California Building Code (Title 24, Part 2) · 2022 edition · updated 2026-09-12 · California
Italicized text is a California amendment to the model code, as printed in the official publication.
310.1 Residential Group R.¶
Residential Group R includes, among others, 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 California Residential Code . Group R occupancies not constructed in accordance with the California Residential Code as permitted by Sections 310.4.1 and 310.4.2 shall comply with Section 420.
310.2 Residential Group R-1.¶
Residential Group R-1 occupancies containing sleeping units where the occupants are primarily transient in nature, including:
Boarding houses (transient) with more than 10 occupants Congregate residences (transient) with more than 10
occupants Hotels (transient) Motels (transient)
[HCD 1] Efficiency dwelling units (transient)
310.3 Residential Group R-2.¶
Residential Group R-2 occupancies containing sleeping units or more than two dwelling units where the occupants are primarily permanent in nature, including:
Apartment houses
Large family child care Small family child care
Congregate residences (nontransient) with more than 16
occupants Boarding houses (nontransient) Convents Dormitories Fraternities and sororities Monasteries Hotels (nontransient) Live/work units Motels (nontransient) Vacation timeshare properties
[HCD 1] Efficiency dwelling units (transient)
310.3.1 Residential Group R-2.1. Residential Group R- 2.1 occupancies shall include buildings, structures or parts thereof housing clients, 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.
This occupancy may contain more than six nonambula- tory and/or bedridden clients. (See Section 435 Special Provisions for Licensed 24-Hour Care Facilities in a Group R-2.1, R-3.1 or R-4 Occupancy). This group shall include, but not be limited to, the following:
Assisted living facilities such as:
Residential care facilities, Residential care facilities for the elderly (RCFEs), Adult residential facilities, Congregate living health facilities, Group homes, Residential care facilities for the chronically ill, Congregate living health facilities for the terminally ill.
Social rehabilitation facilities such as:
Halfway houses, Community correctional centers, Community treatment programs, Work furlough programs, Alcoholism or drug abuse recovery or treatment
facilities.
310.3.2 Residential Group R-2.2 (CDCR Only). Residen- tial occupancies operated by CDCR in a community located facility that provides housing and community-based program services for nontransient ambulatory participants in a nonlicensed facility with 24/7 supervision.
310.4 Residential Group R-3.¶
Residential Group R-3 occupancies where the occupants are primarily permanent in nature
3-12 2022 CALIFORNIA BUILDING CODE
Copyright © 2022 by, or licensed to, International Code Council, Inc. (ALL RIGHTS RESERVED); licensed to California Building Standards Commission pursuant to License Agreement. No further reproductions is authorized. Any unauthorized reproduction or distribution is a violation of the federal copyright act and the license agreement, and subject to civil and criminal penalties thereunder.
and not classified as Group R-1, R-2, R-2.1, R-2.2, R-3.1, R-4 or I, including:
Buildings that do not contain more than two dwelling units Care facilities that provide accommodations for five or
fewer persons receiving care Congregate residences (nontransient) with 16 or fewer
occupants Boarding houses (nontransient) Convents Dormitories Fraternities and sororities Monasteries Congregate residences (transient) with 10 or fewer occupants
[HCD 1] Efficiency dwelling units Boarding houses (transient) Adult care facilities that provide accommodations for six
or fewer clients of any age for less than 24 hours. Licensing categories that may use this classification
include Adult Day Programs. Alcoholism or drug abuse recovery homes (ambulatory
only) Child-care facilities that provide accommodations for six
or fewer clients of any age for less than 24 hours. Licensing categories that may use this classification
include, but are not limited to:
Day-Care Center for Mildly Ill Children, Infant Care Center, School Age Child Day-Care Center. Family Day-Care Homes that provide accommodations
for 14 or fewer children, in the provider’s own home for less than 24-hours. Adult care and child-care facilities that are within a single
family home are permitted to comply with the California Residential Code. Lodging houses (transient) with five or fewer guest rooms
and 10 or fewer occupants
310.4.1 Residential Group R-3.1. This occupancy group may include facilities licensed by a governmental agency for a residentially based 24-hour care facility providing accommodations for six or fewer clients of any age. Clients may be classified as ambulatory, nonambulatory or bedridden. A Group R-3.1 occupancy shall meet the requirements for construction as defined for Group R-3, except as otherwise provided for in Section 435 Special Provisions For Licensed 24-Hour Care Facilities in a Group R-2.1, R-3.1 or R-4 Occupancy. This group may include:
OCCUPANCY CLASSIFICATION AND USE
Nurseries for the full-time care of children under the age of
six, but not including “infants” as defined in Chapter 2
Residential care facilities for the elderly
Small family homes and residential care facilities for the
chronically ill
Exception: Group Homes licensed by the Department of Social Services which provide nonmedical board, room and care for six or fewer ambulatory children or children two years of age or younger, and which do not have any nonambulatory clients shall not be subject to regulations found in Section 435.
Pursuant to Health and Safety Code Section 13143 with respect to these exempted facilities, no city, county or public district shall adopt or enforce any requirement for the prevention of fire or for the protection of life and property against fire and panic unless the requirement would be applicable to a structure regardless of the special occu- pancy. Nothing shall restrict the application of state or local housing standards to such facilities if the standards are applicable to residential occupancies and are not based on the use of the structure as a facility for ambulatory children. For the purpose of this exception, ambulatory children do not include relatives of the licensee or the licensee’s spouse.
310.4.2 Lodging houses. Owner-occupied lodging houses with five or fewer guest rooms and 10 or fewer total occupants shall be permitted to be constructed in accordance with the California Residential Code, provided that an automatic sprinkler system is installed in accordance with Section 903.3.1.3 or Section P2904 of the California Resi- dential Code.
310.5 Residential Group R-4.¶
Residential Group R-4 occupancy shall include buildings, structures or portions thereof for more than six ambulatory clients, but not more than 16 persons, excluding staff, who reside on a 24-hour basis in a supervised residential environment and receive custodial care. The persons receiving care are capable of self-preser- vation. Buildings of Group R-4 shall be classified as one of the occupancy conditions specified in Section 310.5.1 or 310.5.2. This occupancy classification may include a maxi- mum six nonambulatory or bedridden clients (see Section 435, Special Provisions for Licensed 24-Hour Care Facilities in a Group R-2.1, R-3.1 or R-4). Group R-4 occupancies shall meet the requirements in Section 420. This group shall include, but not be limited to, the following:
Assisted living facilities such as:
Residential care facilities, Residential care facilities for the elderly (RCFE), Adult residential facilities, Congregate living health facilities, Group homes.
Social rehabilitation facilities such as:
Halfway houses, Community treatment programs, Work furlough programs, Alcoholism or drug abuse recovery or treatment facilities.
310.6 Large family day-care homes.¶
See Section 455.
Adult residential facilities Congregate living health facilities Intermediate care facilities for the developmentally
disabled habilitative Intermediate care facilities for the developmentally
disabled nursing
Copyright © 2022 by, or licensed to, International Code Council, Inc. (ALL RIGHTS RESERVED); licensed to California Building Standards Commission pursuant to License Agreement. No further reproductions is authorized. Any unauthorized reproduction or distribution is a violation of the federal copyright act and the license agreement, and subject to civil and criminal penalties thereunder.
OCCUPANCY CLASSIFICATION AND USE
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Ask AI about this code▸Contents — California Building Code (Title 24, Part 2)
- Chapter 2 — DEFINITIONS AND ABBREVIATIONS
- Appendix G — FLOOD-RESISTANT
- Appendix L — EARTHQUAKE RECORDING
- Appendix M — TSUNAMI-GENERATED
- Appendix N — REPLICABLE
- Appendix O — PERFORMANCE-BASED
- Chapter 1 — SCOPE AND ADMINISTRATION
▸Chapter 3 — OCCUPANCY CLASSIFICATION AND USE
- Chapter 4 — SPECIAL DETAILED REQUIREMENTS BASED ON OCCUPANCY A…
- Chapter 5 — GENERAL BUILDING HEIGHTS AND AREAS
- Chapter 6 — TYPES OF CONSTRUCTION
- Chapter 7 — FIRE AND SMOKE PROTECTION FEATURES
- Chapter 7A — MATERIALS AND CONSTRUCTION
- Chapter 8 — INTERIOR FINISHES
- Chapter 9 — FIRE PROTECTION AND LIFE SAFETY SYSTEMS
- Chapter 10 — MEANS OF EGRESS
- Chapter 11A — HOUSING ACCESSIBILITY
- Chapter 11B — ACCESSIBILITY TO PUBLIC BUILDINGS, PUBLIC ACCOMM…
- Chapter 12 — INTERIOR ENVIRONMENT
- Chapter 14 — EXTERIOR WALLS
- Chapter 15 — ROOF ASSEMBLIES AND ROOFTOP STRUCTURES
- Chapter 16 — STRUCTURAL DESIGN
- Chapter 16A — STRUCTURAL DESIGN
- Chapter 17 — SPECIAL INSPECTIONS AND TESTS
- Chapter 18 — SOILS AND FOUNDATIONS
- Chapter 19 — CONCRETE
- Chapter 20 — ALUMINUM
- Chapter 21 — MASONRY
- Chapter 22 — STEEL
- Chapter 23 — WOOD
- Chapter 24 — GLASS AND GLAZING
- Chapter 25 — GYPSUM BOARD, GYPSUM PANEL PRODUCTS AND PLASTER
- Chapter 26 — PLASTIC
- Chapter 27 — ELECTRICAL
- Chapter 28 — MECHANICAL SYSTEMS
- Chapter 30 — ELEVATORS AND CONVEYING SYSTEMS
- Chapter 31 — SPECIAL CONSTRUCTION
- Chapter 31B — PUBLIC POOLS
- Chapter 31C — RADIATION
- Chapter 31D — FOOD ESTABLISHMENTS
- Chapter 31F — MARINE OIL TERMINALS
- Chapter 32 — ENCROACHMENTS INTO THE PUBLIC RIGHT-OF-WAY
- Chapter 33 — SAFEGUARDS DURING CONSTRUCTION
- Chapter 35 — REFERENCED STANDARDS
- Appendix A — EMPLOYEE QUALIFICATIONS
- Appendix B — BOARD OF APPEALS
- Appendix C — GROUP U – AGRICULTURAL BUILDINGS
- Appendix D — FIRE DISTRICTS
- Appendix F — RODENTPROOFING
- Appendix H — SIGNS
- Appendix I — PATIO COVERS
- Appendix J — GRADING
- Appendix K — GROUP R-3 AND GROUP R-3.1 OCCUPANCIES
- Appendix P — EMERGENCY HOUSING