IEBC Alteration Levels 1, 2, and 3
Summary
Under the work area method, alterations are classified Level 1 (replacement of materials and equipment), Level 2 (reconfiguration of space up to 50 percent of the building), or Level 3 (reconfiguration of 50 percent or more), and each level adds requirements for fire protection, egress, structure, and energy. The level depends on the measured work area, so define the work area early, because crossing 50 percent changes the scope.
Cols
Scope
- Cites the 2024 IEBC Chapters 6 through 9 as carried in the 2025 California Existing Building Code. The detailed requirement text was not available, so this note gives the classification and section structure. Always verify the adopted code edition and local amendments for the project jurisdiction
- Applies to the work area method only; other methods have their own rules
- Change of occupancy and additions are separate chapters, and repairs are in Chapter 4
Terminology
- Work area: the portion of the building where the work occurs, including the area reconfigured or affected
- Level 1 alteration: replacement or covering of existing materials, elements, equipment, or fixtures using new materials for the same purpose
- Level 2 alteration: reconfiguration of space, addition or elimination of doors or windows, and reconfiguration or extension of systems, up to and including 50 percent of the area of the building
- Level 3 alteration: reconfiguration covering 50 percent or more of the aggregate area of the building
- Aggregate area: the total floor area of the building
- Reconfiguration: moving walls, rooms, or systems, not just refinishing
- Compliance with new construction: the requirement that the altered portion meet the current building code
- Maintaining the level of fire protection: the baseline rule for alterations
- Substantial structural alteration: a structural trigger that increases structural requirements
- Work area compliance: the work area meets the section requirements for its level
Requirements
Classification
| Level | Work | Chapter |
|---|---|---|
| Level 1 | Replacement or covering with new materials for the same purpose; no space reconfiguration | 7 |
| Level 2 | Reconfiguration of space, doors and windows, systems; up to and including 50 percent of the building area | 8 |
| Level 3 | Reconfiguration of 50 percent or more of the aggregate area of the building | 9 |
Section structure by level
| Level 1 (Chapter 7) | Level 2 (Chapter 8) | Level 3 (Chapter 9) |
|---|---|---|
| 701 General | 801 General | 901 General |
| 702 Building elements and materials | 802 Building elements and materials | 902 Special use and occupancy |
| 703 Fire protection | 803 Fire protection | 903 Building elements and materials |
| 704 Means of egress | 804 Means of egress | 904 Fire protection |
| 705 Reroofing | 805 Structural | 905 Means of egress |
| 706 Structural | 806 Electrical | 906 Structural |
| 708 Energy conservation | 807 Mechanical | 907 Energy conservation |
| 809 Energy conservation | 908 Emergency responder communications enhancement system coverage |
Fire protection examples
- Level 1, Section 703.1: alterations are done in a manner that maintains the level of fire protection provided
- Level 1, Sections 703.2.1 and 703.2.2: replacement fire alarm devices and equipment are listed and approved; existing fire alarm and detection systems are maintained under IFC Section 901.7
- Level 2, Section 803.1: requirements apply to the work areas, and extend throughout the floor or beyond where specified
- Level 2, Section 803.1.1: where an approved automatic sprinkler system covers the entire story, the required fire-resistance rating of a corridor on that story may be reduced under the building code; the system covers the stairway landings serving the floor and the intermediate landing below
- Level 2, Section 803.2: sprinklers comply with Section 903 of the building and fire codes
- Level 2, Section 803.4: an approved fire alarm system is installed under IFC Sections 907 and 1103.7
- Level 3, Section 908: emergency responder communications enhancement system coverage
Worked examples
Finding the level
An existing 12,000 sq ft office building.
| Case | Work area | Percent of building | Level |
|---|---|---|---|
| Replace carpet, ceilings, and lights | 12,000 sq ft of finish only | No reconfiguration | Level 1 |
| New partitions and doors on one floor | 5,000 sq ft | 5,000 ÷ 12,000 = 42 percent | Level 2 |
| Reconfigure partitions and systems on a larger area | 6,000 sq ft | 6,000 ÷ 12,000 = 50 percent | Level 3 (50 percent or more) |
| Gut renovation | 10,000 sq ft | 83 percent | Level 3 |
Corridor rating reduction
A Level 2 alteration in a fully sprinklered story.
| Step | Check | Result |
|---|---|---|
| Sprinklers | Approved system covers the entire story and the stairway landings | Section 803.1.1 applies |
| Corridor rating | Required fire-resistance rating | May be reduced under the building code |
| Documentation | Sprinkler coverage drawings | Show the stair landings covered |
Level 3 additional item
| Step | Check | Result |
|---|---|---|
| Level 3 alteration | Section 908 | Evaluate emergency responder radio coverage and provide the system if coverage is inadequate |
Coordination
- Area calculation: document the work area in a diagram with a table of floors and percentages
- Phasing: confirm with the building official how phased work is counted before splitting a project to stay under 50 percent
- Sprinklers: adding sprinklers can earn corridor rating relief and reduce construction
- Accessibility: alterations trigger accessible features and path of travel under federal law
- Fire alarm and radio coverage: Level 3 may trigger responder radio coverage
- Systems: mechanical, electrical, and energy upgrades follow their sections for the level
Common issues
- Miscounting the work area: system and ceiling work extend the area
- Assuming Level 1: moving a single wall makes it Level 2
- Forgetting energy and structure: each level includes structural and energy sections
- Fire alarm triggers: replacing a panel or devices follows listed and approved rules
- Using new-building tables for the whole building: the requirements apply to the work area, with exceptions
Standards
- IEBC Chapters 6 through 9: classification and alteration requirements
- IBC 2024, Section 903: sprinkler requirements referenced by Level 2
- IFC Sections 907 and 901.7: fire alarm installation and maintenance
Sources
- GoCodebook: 2025 California Existing Building Code, Chapter 6 classification of work, https://gocodebook.com/library/us/ca/ca-existing-building-code/chapter-6-classification-of-work
- GoCodebook: 2025 California Existing Building Code, Chapter 7 alterations level 1, https://gocodebook.com/library/us/ca/ca-existing-building-code/chapter-7-alterations-level-1
- GoCodebook: 2025 California Existing Building Code, Chapter 8 alterations level 2, https://gocodebook.com/library/us/ca/ca-existing-building-code/chapter-8-alterations-level-2
- GoCodebook: 2025 California Existing Building Code, Chapter 9 alterations level 3, https://gocodebook.com/library/us/ca/ca-existing-building-code/chapter-9-alterations-level-3