Skip to content

Chapter 9 — ALTERATIONS—LEVEL 3

2025 California Existing Building Code (Title 24, Part 10) · 2025 edition · updated 2026-07-29 · California

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

User notes:

About this chapter : Chapter 9 provides the technical requirements for those existing buildings that undergo Level 3 alterations. The purpose of this chapter is to provide detailed requirements and provisions to identify the required improvements in the existing building elements, building spaces and building structural system. This chapter is distinguished from Chapters 7 and 8 by involving alterations that cover 50 percent or more of the aggregate area of the building. In contrast, Level 1 alterations do not involve space reconfiguration, and Level 2 alterations involve extensive space reconfiguration that does not exceed 50 percent of the building area. Depending on the nature of alteration work, its location within the building, and whether it encompasses one or more tenants, improvements and upgrades could be required for the open floor penetrations, sprinkler system or the installation of additional means of egress such as stairs or fire escapes. At times and under certain situations, this chapter also is intended to improve the safety of certain building features beyond the work area and in other parts of the building where no alteration work might be taking place.

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

Ask AI about this code
▸ Contents — 2025 California Existing Building Code (Title 24, Part 10)
2025 California Existing Building Code (Title 24, Part 10)
  1. Chapter 1 — ADMINISTRATION
  2. Chapter 2 — DEFINITIONS
  3. Chapter 3 — PROVISIONS FOR ALL COMPLIANCE METHODS
  4. Chapter 3A — PROVISIONS FOR ALL COMPLIANCE METHODS
  5. Chapter 4 — REPAIRS
  6. Chapter 4A — REPAIRS
  7. Chapter 5 — PRESCRIPTIVE COMPLIANCE METHOD
  8. Chapter 5A — PRESCRIPTIVE COMPLIANCE METHOD
  9. Chapter 6 — CLASSIFICATION OF WORK
  10. Chapter 7 — ALTERATIONS—LEVEL 1
  11. Chapter 8 — ALTERATIONS—LEVEL 2
  12. ▸ Chapter 9 — ALTERATIONS—LEVEL 3
    Overview
    1. Section 901 — GENERAL
    2. Section 902 — SPECIAL USE AND OCCUPANCY
    3. Section 903 — BUILDING ELEMENTS AND MATERIALS
    4. Section 904 — FIRE PROTECTION
    5. Section 905 — MEANS OF EGRESS
    6. Section 906 — STRUCTURAL
    7. Section 907 — ENERGY CONSERVATION
    8. Section 908 — EMERGENCY RESPONDER COMMUNICATIONS ENHANCEMENT S…
  13. Chapter 10 — CHANGE OF OCCUPANCY
  14. Chapter 11 — ADDITIONS
  15. Chapter 12 — HISTORIC BUILDINGS
  16. Chapter 13 — PERFORMANCE COMPLIANCE METHODS
  17. Chapter 14 — RELOCATED OR MOVED BUILDINGS
  18. Chapter 15 — CONSTRUCTION SAFEGUARDS
  19. Chapter 16 — REFERENCED STANDARDS
  20. Appendix A — GUIDELINES FOR THE SEISMIC RETROFIT OF EXISTING B…
  21. Appendix B — SUPPLEMENTARY ACCESSIBILITY REQUIREMENTS FOR EXIS…
  22. Appendix C — GUIDELINES FOR THE WIND RETROFIT OF EXISTING BUIL…
  23. Appendix D — BOARD OF APPEALS
  24. Appendix E — TEMPORARY EMERGENCY USES
  25. Appendix A — GUIDELINES ON FIRE RATINGS OF ARCHAIC MATERIALS A…

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.