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Chapter 4 — SPECIAL DETAILED REQUIREMENTS BASED

Section 404

California Building Code (Title 24, Part 2) · 2019 edition · updated 2026-09-12 · California

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

404.1 General.

In other than Group H occupancies, and where permitted by Section 712.1.7, the provisions of Sections 404.1 through 404.10 shall apply to buildings or structures containing vertical openings defined as “Atriums.”

404.2 Use.

The floor of the atrium shall not be used for other than low fire hazard uses and only approved materials and decorations in accordance with the California Fire Code shall be used in the atrium space.

Exception: The atrium floor area is permitted to be used for any approved use where the individual space is provided with an automatic sprinkler system in accordance with Section 903.3.1.1.

[F] 404.3 Automatic sprinkler protection. An approved automatic sprinkler system shall be installed throughout the entire building.

Exceptions:

  1. That area of a building adjacent to or above the atrium need not be sprinklered provided that portion of the building is separated from the atrium portion by not less than 2-hour fire barriers constructed in accordance with Section 707 or horizontal assemblies constructed in accordance with Section 711, or both.

  2. Where the ceiling of the atrium is more than 55 feet (16 764 mm) above the floor, sprinkler protection at the ceiling of the atrium is not required.

[F] 404.4 Fire alarm system. A fire alarm system shall be provided in accordance with Section 907.2.13.

404.5 Smoke control.

A smoke control system shall be installed in accordance with Section 909.

Exception: In other than Group I-2, and R-2.1, Condition 2, smoke control is not required for atriums that connect only two stories.

404.6 Enclosure of atriums.

Atrium spaces shall be separated from adjacent spaces by a 1-hour fire barrier constructed in accordance with Section 707 or a horizontal assembly constructed in accordance with Section 711, or both.

Exceptions:

  1. A fire barrier is not required where a glass wall forming a smoke partition is provided. The glass wall shall comply with all of the following:

1.1. Automatic sprinklers are provided along both sides of the separation wall and doors, or on the room side only if there is not a walkway on the atrium side. The sprinklers shall be located between 4 inches and 12

120 2019 CALIFORNIA BUILDING CODE

Copyright © 2019 ICC. ALL RIGHTS RESERVED. Accessed by Kevin Day (kevin.day@dgs.ca.gov), (California Building Standards Commission) Order Number #100735044 on Jul 24, 2019 03:54 PM (PDT) pursuant to License Agreement with ICC. No further reproduction or distribution authorized. Single user only, copying and networking prohibited. 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.

100735044

SPECIAL DETAILED REQUIREMENTS BASED ON OCCUPANCY AND USE

inches (102 mm and 305 mm) away from the glass and at intervals along the glass not greater than 6 feet (1829 mm). The sprinkler system shall be designed so that the entire surface of the glass is wet upon activation of the sprinkler system without obstruction;

1.2. The glass wall shall be installed in a gasketed frame in a manner that the framing system deflects without breaking (loading) the glass before the sprinkler system operates; and

1.3. Where glass doors are provided in the glass wall, they shall be either self-closing or automatic-closing.

  1. A fire barrier is not required where a glass-block wall assembly complying with Section 2110 and having a 3 /4-hour fire protection rating is provided.

  2. In other than Group I and R-2.1 occupancies, a fire barrier is not required between the atrium and the adjoining spaces of up to three floors of the atrium provided that such spaces are accounted for in the design of the smoke control system.

  3. A fire barrier is not required between the atrium and the adjoining spaces where the atrium is not required to be provided with a smoke control system.

[F] 404.7 Standby power. Equipment required to provide smoke control shall be provided with standby power in accordance with Section 909.11.

404.8 Interior finish.

The interior finish of walls and ceilings of the atrium shall be not less than Class B. Sprinkler protection shall not result in a reduction in class.

404.9 Exit access travel distance.

Exit access travel distance for areas open to an atrium shall comply with the requirements of this section.

404.9.1 Egress not through the atrium. Where required access to the exits is not through the atrium, exit access travel distance shall comply with Section 1017.

404.9.2 Exit access travel distance at the level of exit discharge. Where the path of egress travel is through an atrium space, exit access travel distance at the level of exit discharge shall be determined in accordance with Section 1017.

404.9.3 Exit access travel distance at other than the level of exit discharge. Where the path of egress travel is not at the level of exit discharge from the atrium, that portion of the total permitted exit access travel distance that occurs within the atrium shall be not greater than 200 feet (60 960 mm).

404.10 Interior exit stairways.

Not greater than 50 percent of interior exit stairways are permitted to egress through an atrium on the level of exit discharge in accordance with Section 1028.

404.11 Group I and R-2.1 occupancy means of egress.

Required means of egress from sleeping rooms in Group I and R-2.1 occupancies shall not pass through the atrium.

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

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