Do California Tenant Improvements Require Title 24?

The trigger is alteration of a regulated system, not the project label. Lighting work is the most common trigger in office and retail TIs — new layouts, new fixture types, or reconfigured controls. HVAC work follows close behind: new distribution, changed equipment, or altered control sequences. Envelope work such as new storefront glazing or punched openings counts as well. The 2025 California Energy Code / 2025 Standards, effective January 1, 2026, evaluate each altered system against current requirements, so the compliance scope is drawn system by system.

• Lighting layout, fixture, or controls alterations
• HVAC equipment, distribution, or controls changes
• Envelope alterations such as new glazing or openings
• Service water heating changes serving the TI space

Like-for-like repair is the narrowest exception — replacing a failed component with an equivalent stays closest to repair. Anything beyond repair — changed system type, capacity, layout, or controls — must meet current code, while unaltered existing systems are generally not pulled into compliance by the TI scope. The altered scope is documented with NRCC, NRCI, NRCV, and NRCA documents as applicable.

I start every TI by mapping exactly which systems the work touches and stopping there. The permit set should show the altered lighting, the affected HVAC zones, and any envelope changes — and explicitly identify what is existing and untouched. That boundary is what the plan checker reviews and what the acceptance-test technician verifies. Blurry scope lines are where TIs get into trouble: work the team considered minor gets flagged, or testing gets scheduled for systems nobody documented.

• Inventory every regulated system the TI touches
• Draw the compliance boundary on the permit documents
• Identify existing-untouched systems explicitly
• Align acceptance testing with the documented altered scope

The most expensive mistake is discovering compliance at plan check instead of design — a lighting layout that cannot meet current controls requirements gets redrawn under schedule pressure. Second is the shell/TI split: each side assumes the other handled the common systems, and the gap surfaces during inspection. Third is treating acceptance testing as paperwork; lighting controls and economizer tests fail in the field when nobody commissioned them, and rework inside an occupied building costs multiples of doing it right the first time.

• Discovering compliance requirements at plan check, not design
• Shell and TI scopes each assuming the other covered shared systems
• Skipping functional commissioning before acceptance testing
• Undocumented alterations that surface during inspection