Title 24 & ASHRAE 90.1-2026: Mandatory Lighting Controls for Every Commercial Square Foot

Brandon Waldrop

Infographic showing mandatory lighting control requirements under Title 24 and ASHRAE 90.1-2026, including occupancy sensing, daylight harvesting, multi-level dimming, and time scheduling in commercial spaces.

Why Lighting Controls Are No Longer Optional

In most commercial projects, lighting controls are no longer a discretionary design choice. Current energy codes require specific control functions to be shown on the plans and verified in the field, including automatic shutoff, occupancy or vacancy sensing where applicable, and daylight-responsive control in designated daylit zones.

With adoption of ASHRAE 90.1-2026 and continued enforcement of Title 24, compliance is determined not just by installation but by documented commissioning that confirms the controls operate as intended. Systems that are installed but not programmed, tested, or verified can fail inspection despite meeting equipment requirements.

Failure to install required controls can result in failed inspections, permit delays, denied certificates of occupancy, and costly post-install retrofits.

Buying guide reference: If you need a complete interior ceiling-system workflow that ties controls into fixture selection, zoning, retrofit strategy, and inspection-ready documentation, reference the Commercial Ceiling Lighting Buying Guide. For exterior control logic (photocells, schedules, curfews, and survivability variables), use the Commercial Site Lighting Buying Guide.

How Title 24 and ASHRAE 90.1-2026 Work Together

ASHRAE 90.1 serves as the national energy standard adopted or referenced by most U.S. states. Title 24 (California Energy Code) builds on ASHRAE with stricter, more granular requirements.

For practical purposes:

ASHRAE 90.1-2026 establishes the baseline nationwide
Title 24 generally exceeds ASHRAE requirements
Compliance is evaluated by space type, not fixture type

If a project meets Title 24, it will typically exceed ASHRAE 90.1-2026.

Practical note: Always confirm the enforced edition and local amendments with the AHJ (Authority Having Jurisdiction) and your energy compliance documentation set—codes are enforced by jurisdiction and adoption timelines can vary.

Areas Where Occupancy Sensors Are Mandatory

Occupancy or vacancy sensors are now required in most enclosed and intermittently used spaces.

Space Type	Sensor Requirement	Notes
Private offices	Occupancy or vacancy sensor	Auto-off required
Conference rooms	Occupancy sensor	All lighting controlled
Restrooms	Occupancy sensor	No manual bypass
Storage rooms	Occupancy sensor	Including closets
Break rooms	Occupancy sensor	Partial-on allowed

Manual wall switches alone do not satisfy these requirements.

Where Automatic Shutoff Is Legally Required

Both codes mandate automatic shutoff of lighting during unoccupied periods.

Area	Shutoff Requirement	Maximum Time Allowed
Interior spaces	Automatic shutoff	30 minutes after vacancy
Whole building	Scheduled shutoff	Based on business hours
Exterior lighting	Time-based or photocell	Sunrise/sunset or curfew

Timeclocks must be programmable and tamper-resistant.

Daylighting and Zone Control Requirements

ASHRAE 90.1-2026 expands daylight-responsive control requirements.

Automatic dimming in daylight zones
Separate control zones within daylit areas
Continuous dimming preferred over stepped control

Daylight Source	Control Required	Applies When
Windows	Daylight dimming	Within daylight zone
Skylights	Daylight dimming	Primary sidelit areas
Clerestories	Independent zone control	Large open spaces

Binary on/off photocells do not meet 2026 daylighting intent.

Controls Checklist for 2026 Compliance

This checklist reflects minimum requirements—not best practices.

Control Type	Required	Applies To
Occupancy sensors	Yes	Most enclosed spaces
Automatic shutoff	Yes	All interior lighting
Daylight dimming	Yes	Daylit zones
Exterior controls	Yes	All outdoor fixtures
Manual overrides	Limited	Time-restricted

Projects that treat controls as accessories rather than code requirements risk enforcement action.

Inspection-Proof Spec Notes That Prevent Failed Inspections

These spec notes reduce “we installed controls, but it still failed” outcomes by making intent enforceable.

Spec Note	Why It Matters
Provide automatic shutoff for all interior lighting with documented settings	Inspection is about function, not just device presence
Occupancy/vacancy sensors shall control all general lighting in required spaces	Prevents “sensor only controls one circuit” shortcuts
Daylight zones shall be separately controlled with dimming (not on/off only)	Avoids noncompliant photocell-only behavior
Commissioning deliverables required: zone schedule, sensor coverage map, and control narrative	Creates an inspection-ready paper trail and reduces rework
Lock or password-protect time schedules and trim limits after commissioning	Prevents “someone changed it” failures at final inspection

FAQ: Lighting Controls Compliance

Do controls matter if I’m already under the lighting power density limit?

Yes. LPD compliance and control compliance are separate checks. Many projects fail because controls were treated as optional add-ons instead of required functions.

Can I meet requirements with manual switches plus a timeclock?

Sometimes for certain areas, but many spaces still require occupancy-based control and daylight-responsive behavior where applicable. Plans should show which spaces get which control type.

What is the most common reason controls fail inspection?

Controls are installed but not commissioned: wrong sensor coverage, incorrect time schedules, daylight zones not separated, or manual overrides left unlimited.

Under Title 24 and ASHRAE 90.1-2026, lighting controls are no longer a design preference—they are a code-enforced requirement tied to occupancy, daylight availability, and operating hours for virtually every commercial square foot.

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