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Chapter 4 — SPECIAL DETAILED REQUIREMENTS BASED ON OCCUPANCY AND USE

Section 420 — GROUPS R-1, R-2, R-2.1, R-2.2, R-3, R-3.1 AND R-4

2025 California Building Code (Title 24, Part 2) · 2025 edition · updated 2026-07-29 · California

Italicized text is a California amendment to the model code, as printed in the official publication.

420.1 General.

Occupancies in Groups R-1, R-2, R-2.1, R-2.2, R-3, R-3.1 and R-4 shall comply with the provisions of Sections 420.1 through 420.11 and other applicable provisions of this code.

420.2 Separation walls.

Walls separating dwelling units in the same building, walls separating sleeping units in the same building, walls separating dwelling units from sleeping units in the same building and walls separating dwelling or sleeping units from other occupancies contiguous to them in the same building shall be constructed as fire partitions in accordance with Section 708.

420.3 Horizontal separation.

Floor assemblies separating dwelling units in the same buildings, floor assemblies separating sleeping units in the same building, floor assemblies separating dwelling units from sleeping units in the same building and floor assemblies separating dwelling or sleeping units from other occupancies contiguous to them in the same building shall be constructed as horizontal assemblies in accordance with Section 711.

[F] 420.4 Automatic sprinkler system. Group R occupancies shall be equipped throughout with an automatic sprinkler system in accordance with Section 903.2.8. Group R-2.2 shall be equipped throughout with an automatic sprinkler system in accordance with Section 903.3.1.1. Group R-2.1 occupancies shall be equipped throughout with an automatic sprinkler system in accordance with Section 903.2.6. Quick-response or residential automatic sprinklers shall be installed in accordance with Section 903.3.2.

[F] 420.5 Fire alarm systems and smoke alarms. Fire alarm systems and smoke alarms shall be provided in Group R-1, R-2 and R-2.1 occupancies in accordance with Sections 907.2.6, 907.2.8 and 907.2.9 and 907.2.10, respectively. Single- or multiple-station smoke alarms shall be provided in Groups R-2, R-2.1, R-3 and R-4 in accordance with Section 907.2.11. Group R-2.2 shall be equipped through- out with an automatic fire alarm systems per 907.2.9.2 and shall have a manual fire alarm pull station at the 24-hour staff watch office.

420.6 Smoke barriers in Group R-2.1 .

Smoke barriers shall be provided in Group R-2.1 to subdivide every story used by persons receiving care, treatment or sleeping and to provide other stories with an occupant load of 50 or more persons, into not fewer than two smoke compartments. Such stories shall be divided into smoke compartments with an area of not more than 22,500 square feet (2092 m [2] ) and the distance of travel from any point in a smoke compartment to a smoke barrier door shall not exceed 200 feet (60 960 mm). The smoke barrier shall be in accordance with Section 709.

4-52 2025 CALIFORNIA BUILDING CODE

on Jul 18, 2025 11:14 AM (CDT) THEREUNDER.

SPECIAL DETAILED REQUIREMENTS BASED ON OCCUPANCY AND USE

420.6.1 Smoke barrier in Group R-2.2. Occupancies in Group R-2.2 shall have smoke barriers complying with Sections 709 to divide every story occupied by residents for sleeping, into no fewer than two smoke compartments.

Exception: Spaces having a direct exit to a public way.

420.6.2 Refuge area. Refuge areas shall be provided within each smoke compartment. The size of the refuge area shall accommodate the occupants and care recipients from the adjoining smoke compartment. Where a smoke compartment is adjoined by two or more smoke compartments, the minimum area of the refuge area shall accommodate the largest occupant load of the adjoining compartments. The size of the refuge area shall provide the following:

  1. Not less than 15 net square feet (1.4 m [2] ) for each care recipient.
  2. Not less than 6 net square feet (0.56 m [2] ) for other occupants.

Areas or spaces permitted to be included in the calculation of the refuge area are corridors, lounge or dining areas and other low-hazard areas.

420.7 Reserved.

420.8 Reserved.

420.9 Domestic cooking appliances.

In Group R-2.1 occupancies, installation of cooking appliance used in domestic cooking facilities shall comply with all of the following:

  1. The types of cooking appliances permitted shall be limited to ovens, cooktops, ranges, warmers and microwaves.
  2. Domestic cooking hoods installed and constructed in accordance with the California Mechanical Code shall be provided over cooktops or ranges.
  3. Cooktops and ranges shall be protected in accordance with Section 904.15.
  4. A shutoff for the fuel and electrical supply to the cooking equipment shall be provided in a location to which only staff has

access.

  1. A timer shall be provided that automatically deactivates the cooking appliances within a period of not more than 120 minutes.

  2. A portable fire extinguisher shall be provided. Installation shall be in accordance with Section 906 and the extinguisher shall be located within a 30-foot (9144 mm) distance of travel from each domestic cooking appliance.

Exceptions:

  1. Cooking facilities provided within care recipients’ individual dwelling units are not required to comply with this section.
  2. Cooktops and ranges used for care-recipient training or nutritional counseling are not required to comply with Item 3 of this section.

420.10 Group R cooking facilities.

In Group R occupancies, cooking appliances used for domestic cooking operations shall be in accordance with the California Mechanical Code .

420.11 Group R-2 dormitory cooking facilities.

Domestic cooking appliances for use by residents of Group R-2 college dormitories shall be in accordance with Sections 420.11.1 and 420.11.2.

420.11.1 Cooking appliances. Where located in Group R-2 college dormitories, domestic cooking appliances for use by residents shall be in compliance with all of the following:

  1. The types of domestic cooking appliances shall be limited to ovens, cooktops, ranges, warmers, coffee makers and microwaves.

  2. Domestic cooking appliances shall be limited to approved locations.

  3. Cooktops and ranges shall be protected in accordance with Section 904.15.

  4. Cooktops and ranges shall be provided with a domestic cooking hood installed and constructed in accordance with the California Mechanical Code . Kitchen range hoods shall also be rated for sound and meet field verification requirements in the California Energy Code for low-rise and high-rise residential buildings.

420.11.2 Cooking appliances in sleeping rooms. Cooktops, ranges and ovens shall not be installed or used in sleeping rooms.

420.12 [HCD 1] Construction waste management.

Recycle and/or salvage for reuse a minimum of 65 percent of the nonhazardous construction and demolition waste in accordance with the California Green Building Standards Code (CALGreen), Chapter 4, Division 4.4.

420.13 Special provisions for residential hotels. [HCD 1 & HCD 1-AC]

420.13.1 Locking mail receptacles. A locking mail receptacle for each residential unit shall be provided in all residential hotels pursuant to the requirements specified in Health and Safety Code Section 17958.3.

420.14 [HCD 1] Electric vehicle (EV) charging for new construction.

Newly constructed Group R-1, R-2 and R-3 buildings shall meet requirements for electric vehicle charging in accordance with the California Green Building Standards Code (CALGreen), Chapter 4, Divi- sion 4.1.

420.15 Licensed 24-hour care facilities in a Group R-2.1, R-3.1 or R-4 occupancy.

See Section 435 for Special Provisions for licensed 24-hour care facilities in a Group R-2.1, R-3.1 or R-4 occupancy.

420.16 Electronic monitoring.

In Group R-2.2 occupancies there shall be continuous electronic supervision via CCTV system camera coverage and monitoring the following areas: corridors, storage rooms over 100 square feet, central kitchen and main entryway of the facility.

on Jul 18, 2025 11:14 AM (CDT) THEREUNDER.

SPECIAL DETAILED REQUIREMENTS BASED ON OCCUPANCY AND USE

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▸ Contents — 2025 California Building Code (Title 24, Part 2)
2025 California Building Code (Title 24, Part 2)
  1. Chapter 1 — ADMINISTRATION
  2. Chapter 2 — DEFINITIONS
  3. Chapter 3 — OCCUPANCY CLASSIFICATION AND USE
  4. ▸ Chapter 4 — SPECIAL DETAILED REQUIREMENTS BASED ON OCCUPANCY A…
    Overview
    1. Section 401 — SCOPE
    2. Section 402 — COVERED MALL AND OPEN MALL BUILDINGS
    3. Section 403 — HIGH-RISE BUILDINGS AND GROUP I-2 OCCUPANCIES HA…
    4. Section 404 — ATRIUMS
    5. Section 405 — UNDERGROUND BUILDINGS
    6. Section 406 — MOTOR-VEHICLE-RELATED OCCUPANCIES
    7. Section 407 — GROUP I-2
    8. Section 408 — GROUP I-3
    9. Section 409 — MOTION PICTURE PROJECTION ROOMS
    10. Section 410 — STAGES, PLATFORMS AND TECHNICAL PRODUCTION AREAS
    11. Section 411 — SPECIAL AMUSEMENT AREAS
    12. Section 412 — AIRCRAFT-RELATED OCCUPANCIES
    13. Section 413 — COMBUSTIBLE STORAGE
    14. Section 414 — HAZARDOUS MATERIALS
    15. Section 415 — GROUPS H-1, H-2, H-3, H-4 AND H-5
    16. Section 416 — SPRAY APPLICATION OF FLAMMABLE FINISHES
    17. Section 417 — DRYING ROOMS
    18. Section 418 — ORGANIC COATINGS
    19. Section 419 — ARTIFICIAL DECORATIVE VEGETATION
    20. Section 420 — GROUPS R-1, R-2, R-2.1, R-2.2, R-3, R-3.1 AND R-4
    21. Section 421 — HYDROGEN FUEL GAS ROOMS
    22. Section 422 — AMBULATORY CARE FACILITIES
    23. Section 423 — STORM SHELTERS
    24. Section 424 — PLAY STRUCTURES
    25. Section 425 — HYPERBARIC FACILITIES
    26. Section 427 — MEDICAL GAS SYSTEMS
    27. Section 435 — SPECIAL PROVISIONS FOR LICENSED 24-HOUR CARE FAC…
    28. Section 436 — GROUP I-4 [SFM]
    29. Section 437 — RESERVED
    30. Section 438 — RESERVED
    31. Section 439 — ROAD TUNNELS, BRIDGES AND OTHER LIMITED-ACCESS H…
    32. Section 440 — HORSE RACING STABLES [SFM]
    33. Section 441 — PET KENNELS AND PET BOARDING FACILITIES [SFM]
    34. Section 442 — COMBUSTION ENGINES AND GAS TURBINES [SFM]
    35. Section 443 — FIXED GUIDEWAY TRANSIT AND PASSENGER RAIL SYSTEM…
    36. Section 444 — EXPLOSIVES [SFM]
    37. Section 445 — RESERVED
    38. Section 446 — WINERY CAVES [SFM]
    39. Section 447 — RESERVED
    40. Section 448 — RESERVED
    41. Section 449 — PUBLIC LIBRARIES [SL AND SFM]
    42. Section 450 — GROUP C [SFM]
    43. Section 451 — RESERVED
    44. Section 452 — SCHOOL FACILITIES FOR KINDERGARTEN THROUGH 12TH …
    45. Section 453 — GROUP L [SFM]
    46. Section 454 — RESERVED
    47. Section 455 — LARGE FAMILY DAY-CARE HOMES [SFM]
  5. Chapter 5 — GENERAL BUILDING HEIGHTS AND AREAS
  6. Chapter 6 — TYPES OF CONSTRUCTION
  7. Chapter 7 — FIRE AND SMOKE PROTECTION FEATURES
  8. Chapter 7A — MATERIALS AND CONSTRUCTION METHODS FOR EXTERIOR W…
  9. Chapter 8 — INTERIOR FINISHES
  10. Chapter 9 — FIRE PROTECTION AND LIFE SAFETY SYSTEMS
  11. Chapter 10 — MEANS OF EGRESS
  12. Chapter 11 — RESERVED
  13. Chapter 11A — HOUSING ACCESSIBILITY
  14. Chapter 11B — ACCESSIBILITY TO PUBLIC BUILDINGS, PUBLIC ACCOMM…
  15. Chapter 12 — INTERIOR ENVIRONMENT
  16. Chapter 13 — ENERGY EFFICIENCY
  17. Chapter 14 — EXTERIOR WALLS
  18. Chapter 15 — ROOF ASSEMBLIES AND ROOFTOP STRUCTURES
  19. Chapter 16 — STRUCTURAL DESIGN
  20. Chapter 16A — STRUCTURAL DESIGN
  21. Chapter 17 — SPECIAL INSPECTIONS AND TESTS
  22. Chapter 17A — SPECIAL INSPECTIONS AND TESTS
  23. Chapter 18 — SOILS AND FOUNDATIONS
  24. Chapter 18A — SOILS AND FOUNDATIONS
  25. Chapter 19 — CONCRETE
  26. Chapter 19A — CONCRETE
  27. Chapter 20 — ALUMINUM
  28. Chapter 21 — MASONRY
  29. Chapter 21A — MASONRY
  30. Chapter 22 — STEEL
  31. Chapter 22A — STEEL
  32. Chapter 23 — WOOD
  33. Chapter 24 — GLASS AND GLAZING
  34. Chapter 25 — GYPSUM PANEL PRODUCTS AND PLASTER
  35. Chapter 26 — PLASTIC
  36. Chapter 27 — ELECTRICAL
  37. Chapter 28 — MECHANICAL SYSTEMS
  38. Chapter 29 — PLUMBING SYSTEMS
  39. Chapter 30 — ELEVATORS AND CONVEYING SYSTEMS
  40. Chapter 31 — SPECIAL CONSTRUCTION
  41. Chapter 31A — SYSTEMS FOR WINDOW CLEANING OR EXTERIOR BUILDING…
  42. Chapter 31B — PUBLIC POOLS
  43. Chapter 31C — RADIATION
  44. Chapter 31D — FOOD ESTABLISHMENTS
  45. Chapter 31F — MARINE OIL TERMINALS
  46. Chapter 32 — ENCROACHMENTS INTO THE PUBLIC RIGHT-OF-WAY
  47. Chapter 33 — SAFEGUARDS DURING CONSTRUCTION
  48. Chapter 34 — RESERVED
  49. Chapter 35 — REFERENCED STANDARDS
  50. Appendix A — EMPLOYEE QUALIFICATIONS
  51. Appendix B — BOARD OF APPEALS
  52. Appendix C — GROUP U—AGRICULTURAL BUILDINGS
  53. Appendix D — FIRE DISTRICTS
  54. Appendix E — RESERVED
  55. Appendix F — RODENTPROOFING
  56. Appendix G — FLOOD-RESISTANT CONSTRUCTION
  57. Appendix H — SIGNS
  58. Appendix I — PATIO COVERS
  59. Appendix J — GRADING
  60. Appendix K — GROUP R-3 AND GROUP R-3.1 OCCUPANCIES PROTECTED B…
  61. Appendix L — EARTHQUAKE RECORDING INSTRUMENTATION
  62. Appendix M — TSUNAMI-GENERATED FLOOD HAZARDS
  63. Appendix N — REPLICABLE BUILDINGS
  64. Appendix O — PERFORMANCE-BASED APPLICATION
  65. Appendix P — SLEEPING LOFTS
  66. Appendix Q — EMERGENCY HOUSING

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