Types

• IEBC Additions
  IEBC Chapter 11 rules for additions, covering height and area limits, fire protection, and structural thresholds for existing gravity and lateral elements.
• IEBC Alteration Levels 1, 2, and 3
  IEBC work area method classifying alterations as Level 1, 2, or 3 by how much of the building is reconfigured, and what each triggers.
• IEBC Change of Occupancy
  IEBC Chapter 10 rules for changing the use of an existing building, ranking relative hazard to set egress, area, and fire protection upgrades.
• IEBC Compliance Methods
  The three IEBC compliance methods for existing buildings, prescriptive, work area, and performance, and how to choose one for a renovation.
• IEBC Historic Buildings
  IEBC Chapter 12 provisions giving designated historic buildings alternative, less restrictive ways to meet code for repairs, fire safety, alterations, and change of use.

Scope and application

• Covers existing buildings and structures undergoing repair, alteration, addition, change of occupancy, or relocation; new construction follows the IBC
• Gives reduced, proportionate requirements so that work on an old building does not require a full upgrade to new-building standards
• The IBC and IFC still apply where the IEBC refers to them; many IEBC sections cite the building code for the requirement that applies to the changed area
• Historic buildings have their own chapter with added flexibility
• Provisions in other I-Codes on repairs, alterations, additions, relocation, and changes of occupancy must still be addressed unless they conflict with the IEBC, in which case the IEBC governs
• The NFPA 101 Life Safety Code also covers existing buildings and is an alternative framework where adopted

Editions and adoption

Always verify the adopted code edition and local amendments for the project jurisdiction.

Governing editions

• The 2024 IEBC is reported to increase the building official's authority to determine compliance and to bar combustible exterior wall coverings without a sprinkler system; one draft summary lists these among its changes
• The IEBC text could not be read directly; the provisions here come from the California Existing Building Code (Title 24, Part 10, effective January 1, 2026) and from secondary summaries
• California did not adopt the historic buildings chapter or the performance compliance chapter; model code jurisdictions generally do
• States and local jurisdictions adopt the IEBC with amendments; adoption can lag the IBC

Enforcement and administration

• The building official enforces the IEBC through permit review and inspection of the work and the affected areas
• The design team documents the compliance method, the work area, and the classification of work in the permit set
• Alternative means and equivalencies are approved by the building official
• Appeals go to a board of appeals (the model code includes an appendix for a board of appeals)

How the code is organized

Using the code

The path through an existing building review:

1. Choose the compliance method under IEBC Compliance Methods
2. Classify the work and the work area under IEBC Alteration Levels 1, 2, and 3
3. If the building enlarges, apply IEBC Additions
4. If the use changes, apply IEBC Change of Occupancy
5. If the building is a designated historic building, consider IEBC Historic Buildings and the local review in Overlay Districts and Historic Review
6. Check accessibility, smoke alarms, and structure that apply to all methods

Referenced standards

Sources

• GoCodebook: 2025 California Existing Building Code (follows the 2024 IEBC structure), https://gocodebook.com/library/us/ca/ca-existing-building-code
• Westwood, KS: 2024 International Codes significant changes, draft, https://mccmeetingspublic.blob.core.usgovcloudapi.net/westwoodks-meet-30e095f58d814b9c88565f2f3285e5af/ITEM-Attachment-001-f129eed3ff9e4b44a00ef260958d6d62.pdf