Skip to content

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

Get a plain-English answer with a citation back to this text.

Ask AI about this code
Contents — California Building Code (Title 24, Part 2)
California Building Code (Title 24, Part 2)
  1. Chapter 2 — DEFINITIONS AND ABBREVIATIONS
  2. Appendix G — FLOOD-RESISTANT
  3. Appendix L — EARTHQUAKE RECORDING
  4. Appendix M — TSUNAMI-GENERATED
  5. Appendix N — REPLICABLE
  6. Appendix O — PERFORMANCE-BASED
  7. Chapter 1 — SCOPE AND ADMINISTRATION
  8. Chapter 3 — OCCUPANCY CLASSIFICATION AND USE
  9. Chapter 4 — SPECIAL DETAILED REQUIREMENTS BASED ON OCCUPANCY A…
  10. Chapter 5 — GENERAL BUILDING HEIGHTS AND AREAS
  11. Chapter 6 — TYPES OF CONSTRUCTION
  12. Chapter 7 — FIRE AND SMOKE PROTECTION FEATURES
  13. Chapter 7A — MATERIALS AND CONSTRUCTION
  14. Chapter 8 — INTERIOR FINISHES
  15. Chapter 9 — FIRE PROTECTION AND LIFE SAFETY SYSTEMS
  16. Chapter 10 — MEANS OF EGRESS
  17. Chapter 11A — HOUSING ACCESSIBILITY
  18. Chapter 11B — ACCESSIBILITY TO PUBLIC BUILDINGS, PUBLIC ACCOMM…
  19. Chapter 12 — INTERIOR ENVIRONMENT
  20. Chapter 14 — EXTERIOR WALLS
  21. Chapter 15 — ROOF ASSEMBLIES AND ROOFTOP STRUCTURES
  22. Chapter 16 — STRUCTURAL DESIGN
  23. Chapter 16A — STRUCTURAL DESIGN
  24. Chapter 17 — SPECIAL INSPECTIONS AND TESTS
  25. Chapter 18 — SOILS AND FOUNDATIONS
  26. Chapter 19 — CONCRETE
  27. Chapter 20 — ALUMINUM
  28. Chapter 21 — MASONRY
  29. Chapter 22 — STEEL
  30. Chapter 23 — WOOD
  31. Chapter 24 — GLASS AND GLAZING
  32. Chapter 25 — GYPSUM BOARD, GYPSUM PANEL PRODUCTS AND PLASTER
  33. Chapter 26 — PLASTIC
  34. Chapter 27 — ELECTRICAL
  35. Chapter 28 — MECHANICAL SYSTEMS
  36. Chapter 30 — ELEVATORS AND CONVEYING SYSTEMS
  37. Chapter 31 — SPECIAL CONSTRUCTION
  38. Chapter 31B — PUBLIC POOLS
  39. Chapter 31C — RADIATION
  40. Chapter 31D — FOOD ESTABLISHMENTS
  41. Chapter 31F — MARINE OIL TERMINALS
  42. Chapter 32 — ENCROACHMENTS INTO THE PUBLIC RIGHT-OF-WAY
  43. Chapter 33 — SAFEGUARDS DURING CONSTRUCTION
  44. Chapter 35 — REFERENCED STANDARDS
  45. Appendix A — EMPLOYEE QUALIFICATIONS
  46. Appendix B — BOARD OF APPEALS
  47. Appendix C — GROUP U – AGRICULTURAL BUILDINGS
  48. Appendix D — FIRE DISTRICTS
  49. Appendix F — RODENTPROOFING
  50. Appendix H — SIGNS
  51. Appendix I — PATIO COVERS
  52. Appendix J — GRADING
  53. Appendix K — GROUP R-3 AND GROUP R-3.1 OCCUPANCIES
  54. Appendix P — EMERGENCY HOUSING

GoCodebook provides public access, search, citation, multilingual explanation, and practical interpretation of legally adopted building regulations. It is not a substitute for the official ICC or California code publications.