Title 24 commercial lighting: requirements that matter.
California Title 24 Part 6 (Energy Code) governs commercial lighting design — power density limits, mandatory controls, acceptance testing.
By Steven Lockhart · Reviewed by Alex Towery, C-10 #989290
Updated 2026-06-16
Title 24 commercial lighting requirements for new and substantially-retrofitted lighting: Lighting Power Density (LPD) limits per space type (office ~0.75 W/sq ft, retail 0.9-1.5 W/sq ft, restaurant ~1.0 W/sq ft), mandatory occupancy/vacancy sensors in most spaces, daylight harvesting in spaces with qualifying window exposure, automatic shut-off for unoccupied periods, acceptance testing verifying controls function. Non-compliance fails inspection; properly-designed lighting passes first time.
01What Title 24 actually requires.
LPD limits: maximum allowed lighting power per square foot per space type. Modern LED easily meets limits in most spaces; high-design retail or specialty spaces sometimes push limits. Calculation done at design phase; verified at acceptance testing. Controls requirements: vacancy or occupancy sensors in most enclosed spaces, daylight harvesting in spaces with qualifying daylight, automatic shut-off for unoccupied buildings. Implementation via standalone sensors (smaller spaces) or networked control (larger spaces).
Acceptance testing: post-install verification that controls function as designed. Required for permit closure on most TI lighting work. Common acceptance test failures: occupancy sensor timing wrong, daylight harvesting not actually dimming, manual override missing. Quality control programming prevents these issues.
02Three areas where Title 24 compliance most often fails.
Occupancy sensor timing
Title 24 specifies sensor delay times (typically 5-15 minutes maximum before lights turn off after motion stops). Default sensor settings often outside compliance. Acceptance testing verifies delays match code.
Daylight harvesting in qualifying spaces
Spaces with adequate window exposure (specific criteria) require daylight harvesting — automatic dimming when natural light is sufficient. Often overlooked in design or implementation. Acceptance testing verifies dimming actually happens with natural light.
Multi-level switching or manual override
Title 24 requires occupant ability to override automatic controls. Specific implementation varies by space type. Common oversight; clarified during design and verified at acceptance test.
03How we handle Title 24 on projects.
Pre-construction: review architectural drawings for Title 24 implications, calculate LPD compliance for proposed lighting design, identify control requirements per space type, document compliance approach in project quote. Some projects require Title 24 documentation from licensed energy consultant; we coordinate when required.
Execution: install per Title 24-compliant design, configure controls per code requirements, document compliance throughout. Acceptance testing at project completion: walk through with AHJ inspector (or third-party acceptance testing provider in some jurisdictions), demonstrate controls functioning per code. First-pass acceptance test rate 95%+ in our project history through systematic compliance approach.
Common questions.
Does Title 24 apply to retrofit?
Depends on scope. Like-for-like lamp replacement: generally exempt. Substantial retrofit (>10% of space lighting power changed, or fixture replacement) triggers full Title 24 compliance including LPD limits, controls, acceptance testing. Most meaningful retrofit projects trigger compliance.
What's acceptance testing?
Post-install verification that lighting controls function per Title 24 requirements. Tests: sensor activation and timing, daylight harvesting dimming, manual override functionality, automatic shut-off operation. Required for permit closure on most commercial lighting work. We coordinate testing as project scope.
Who can do Title 24 acceptance testing?
AHJ inspectors in some jurisdictions; third-party Title 24 acceptance test providers in others. Some jurisdictions accept contractor self-certification with documentation. We handle the appropriate path for each jurisdiction.
How do you handle pricing — flat fee or hourly?
Both, depending on scope. Routine service calls and predictable scope (panel replacement, EV charger install, transfer switch install, fixture replacement) are flat-fee quoted up front. Diagnostic visits and emergency scope are hourly because we don't know what we'll find. Either way, you get a written quote before work starts on anything significant, and we don't proceed beyond the quote without your sign-off.
How quickly can you schedule?
Depends on scope and season. Emergency dispatch: same-day across Marin County (1-3 hours business hours, 1-4 hours after-hours). Same-day standard service: 3-6 hours from call when capacity allows; otherwise next business day. Scheduled service work: 1-3 weeks typical. Larger projects requiring permits and PG&E coordination: 4-12 weeks depending on scope. We're upfront about timeline at the quote stage.
What warranty do you offer on work?
Our standard residential warranty: 2 years on labor, manufacturer warranty on parts (varies by product — typically 1-10 years). Major installs (panels, generators, EV chargers) often have longer manufacturer warranties (5-10 years). If there's an issue with our work in the warranty period, we come back and fix it at no cost. We also stand behind work past warranty — repeat customers and referrals matter more than a transactional fix.
Are you licensed and insured?
Yes. California State License Board C-10 Electrical Contractor #989290, in good standing. Carry general liability insurance and workers' compensation insurance as required by California law. Bondable on projects requiring it. Happy to provide proof of insurance to clients or property managers on request. License lookup: cslb.ca.gov.
Talk to a licensed electrician in Marin.
Family-run, C-10 #989290, 20+ years in the trade. Honest scoping, fair pricing, work that lasts.