Title 24 Compliance: Retrofit Lighting Controls for Warehouses – Hyperlite

Bringing an older California facility up to current Title 24, Part 6 lighting requirements almost always comes down to one thing: controls. Swapping in efficient LED fixtures helps, but you do not pass inspection unless the controls strategy matches the code. This guide focuses on retrofitting existing spaces with 0–10 V dimming and sensor-ready luminaires so contractors, facility managers, and engineers can hit Title 24 targets without ripping out every circuit.

UFO LED High Bay and shop lights illuminating a high-ceiling wood-trussed garage/workshop

1. What Title 24 Really Expects From a Retrofit

California’s Title 24, Part 6 is performance-driven. For lighting retrofits, most pain points are not about lumens or fixture counts, but about how lights turn on, off, and dim.

According to the California Energy Commission’s Title 24 2022 resources, the code’s goals are:

Reduce lighting power density (LPD) through high‑efficacy luminaires
Require automatic shutoff when spaces are vacant
Capture daylight savings whenever feasible
Ensure controllability (multi‑level or continuous dimming)

In practice, that translates into four control pillars on most projects:

Occupancy/vacancy sensing
Daylight‑responsive dimming near fenestration
Multi‑level or continuous dimming (0–10 V or digital)
Automatic shutoff / scheduling for larger zones

For warehouses and industrial spaces, Title 24 pairs these with specific application guidance. The 2022 Lighting Controls Application Resource Guide for Title 24 notes that high‑bay zones typically require automatic shutoff plus multi‑level dimming and, in many cases, daylighting in perimeter aisles. These are exactly the spaces where UFO and linear high bays dominate, so control compatibility becomes a make‑or‑break specification.

If you work primarily on warehouses, you can pair this guide with the dedicated deep dive on zoning and dimming logic in How to Zone UFO High Bay Dimming Controls.

2. Retrofit Strategy: Start With the Control “Map”

2.1 Inventory Before You Touch a Fixture

Every successful Title 24 control retrofit starts on paper, not on the lift. Before ordering a single sensor, capture:

Space types and areas (warehouse aisles, loading docks, mezzanines, offices)
Mounting heights by zone
Existing circuiting and panel schedules
Existing control devices (time clocks, photocells, legacy occupancy sensors)
Planned luminaire types (UFO high bays vs linear high bays, wall packs, troffers)

Tie each area back to applicable Title 24 requirements using the 2022 Lighting Controls Reference Guide from 16500.com. It provides space‑by‑space tables clarifying where vacancy sensors are mandatory, what counts as multi‑level control, and when partial‑OFF is required. Use these tables to mark up a one‑line diagram with control intents for each circuit.

2.2 Decide Where You Will Re‑Use vs Replace Controls

On real projects, replacing every control is rarely viable. A practical retrofit map usually falls into three buckets:

Keep and integrate: Existing time clocks or BMS schedules that you can treat as the top‑level “on” signal
Upgrade in place: Replacing outdated line‑voltage sensors with line‑voltage‑plus‑0–10 V models so you gain dimming capability
Add new: 0–10 V sensor nodes at the fixture or row level in areas that never had automatic control

The DOE’s Wireless Occupancy Sensors applications guide shows how federal facilities routinely layer wireless sensors over existing circuits instead of rewiring entire buildings. That same principle works for Title 24 retrofits: use existing switched legs as enable lines and overlay wireless or low‑voltage networks to achieve code‑grade control granularity.

2.3 Control Strategy Snapshot Table

Use a simple table like this early in design to align the whole team:

Space type	Mounting height	Required controls (typical Title 24)	Retrofit approach
Warehouse aisles	25–35 ft	Occupancy + multi‑level + partial‑OFF	High‑bay sensors on 0–10 V drivers, grouped by 2–4 bays
Open warehouse floor	20–25 ft	Occupancy + multi‑level, daylight near skylights	Row sensors + daylight sensors for perimeter rows
Loading docks	15–20 ft	Occupancy/vacancy + partial‑OFF	Line‑voltage wall sensors + 0–10 V dimming
Mezzanines/stairs	10–14 ft	Vacancy + partial‑OFF	Wall‑box vacancy sensors + multi‑level switches
Offices/support rooms	8–10 ft	Vacancy + multi‑level dimming	Wall‑box dimmers with 0–10 V output

This chart is not the code itself, but a field‑tested starting point; always confirm exact triggers and exceptions with the current Title 24 guidance and local amendments.

LED High Bay fixtures lighting a high-ceiling industrial warehouse assembly floor

3. Choosing Sensor‑Ready Fixtures and 0–10 V Drivers

3.1 Why 0–10 V Is the Retrofit Workhorse

For existing buildings, 0–10 V analog dimming remains the most reliable path to Title 24 multi‑level or continuous dimming. The NEMA Lighting Controls Association’s resources on control basics, summarized in their Education Express courses, emphasize that 0–10 V offers:

Broad driver support in commercial luminaires
Predictable behavior with stand‑alone sensors and wall controls
Simple point‑to‑point wiring that most electricians already understand

Digital protocols and networked lighting controls (NLC) unlock additional savings and advanced features, but they also demand commissioning expertise and usually a different budget level. For many small to mid‑size Title 24 projects, a robust 0–10 V backbone with a few wireless bridges hits the practical sweet spot.

3.2 Driver Compatibility: Sinking vs Sourcing

A critical lesson from retrofit field work: not all “dimmable” fixtures behave with every control. Some proprietary drivers source current on the 0–10 V leads instead of sinking, or they expect a limited range of control voltages.

Practical process that saves projects:

Order one sample luminaire for each driver family.
Bench‑test it with the exact sensors or wall controls planned for the job.
Verify that:
- The fixture reliably turns fully off or to at least 10% output.
- There is no flicker or drop‑out at low levels.
- The fade behavior (ramp up/down) meets owner expectations.

Retrofit teams routinely avoid callbacks by catching these issues in the shop instead of 30 ft in the air.

3.3 Sensor Ports, Plugs, and “Sensor‑Ready” Really Mean Wiring Flexibility

“Sensor‑ready” should not just be a marketing term. When you are evaluating fixtures for a Title 24 retrofit, focus on three concrete features:

Dedicated low‑voltage chamber or port separate from line‑voltage conductors
Clearly labeled 0–10 V terminals or leads, color‑coded per NEC and manufacturer docs
Mounting provisions for integral or plug‑in sensors (knockouts, receptacles, brackets)

These details directly affect labor. Luminaires with pre‑terminated low‑voltage leads and mechanical accommodations for sensor heads let crews trim several minutes per fixture. Across a 200‑fixture warehouse, that often saves an entire day of lift time.

The DOE’s High‑Efficiency Troffer Performance Specification highlights dimming and control integration as key selection criteria even for indoor panel fixtures. Apply that same logic to high bays and wall packs: drivers and housings must welcome controls, not fight them.

4. Wiring 0–10 V and Sensors for Code and Reliability

4.1 Treat 0–10 V as Class 1 vs Class 2 Correctly

The NEC (NFPA 70) defines how low‑voltage control circuits must be installed and separated from power conductors. The overview from NFPA 70 documentation makes one thing clear: you cannot assume the purple and gray leads can be run any way you like.

Key field rules that align with NEC concepts and manufacturer instructions:

Verify whether the 0–10 V circuit is Class 1 or Class 2 per the driver datasheet.
Do not mix Class 2 control conductors in the same raceway as line‑voltage conductors unless both insulation ratings and code allow it.
Terminate all low‑voltage splices in rated enclosures; avoid loose in‑canopy wire nuts on long daisy chains.

This is an area where inspectors often focus once they realize 0–10 V is present. Clean segregation and documentation defuse most questions.

4.2 Keep Control Runs Short and Clean

0–10 V is analog and susceptible to noise and voltage drop. For stable dimming across a zone:

Use 18–22 AWG twisted pair for low‑voltage runs.
Keep total control run length under roughly 100 ft per zone when feasible.
Route low‑voltage conductors away from high‑voltage feeders to reduce induced noise.

In the field, keeping zones compact typically improves dimming consistency by 10–20% compared to sprawling control loops that bounce through 200–300 ft of conduit and multiple junction points.

4.3 Sensor Selection vs Mounting Height

Choosing the wrong sensor for the mounting height is one of the fastest ways to fail both Title 24 intent and occupant expectations.

Below ~15 ft: Ceiling‑mount passive infrared (PIR) sensors perform well and give tight coverage.
20–30+ ft: Standard PIR patterns collapse; coverage donuts do not reach the floor reliably.
High bays: Use sensors rated for high mounting heights—microwave or dual‑technology units with defined patterns at 30–40 ft.

The DOE’s wireless occupancy sensor guide documents how undersized sensors in high‑bay applications cause both nuisance shutoff and dead zones. For Title 24 projects, specify sensors with published mounting height limits and pattern diagrams, and match them to the as‑built dimensions.

UFO LED High Bay shop lights illuminating a timber-framed pole barn warehouse

4.4 Commission to a Safe Minimum Dim Level

Title 24 wants energy savings, but egress safety and usability always come first. A field‑tested approach:

Set occupied light level to meet or exceed recommended illuminance from guides such as ANSI/IES RP‑7 for industrial facilities.
Set unoccupied level to 10–20% for high bays rather than complete OFF, unless the owner explicitly accepts full shutoff.
Verify that the lowest setpoint does not introduce flicker or drop‑out in any fixture in the zone.

Document the resulting dim curve and time delays in an as‑built schedule. Inspectors appreciate clear evidence that the system both saves energy and respects safety.

5. Layering Controls to Satisfy Title 24 Without Conflicts

5.1 Establish a Clear Control Hierarchy

Many existing buildings already have photocells, time clocks, or BMS commands. Title 24 often adds occupancy and daylighting layers on top. Without a hierarchy, these can fight each other—for example, a photocell forces lights on at dusk while a sensor tries to turn them off due to vacancy.

A practical hierarchy that aligns with Title 24’s intent:

Enable layer: Time clock or BMS decides when a zone is allowed to operate (e.g., during business hours).
Daylight layer: Photocell or indoor daylight sensor trims output when daylight is available.
Occupancy layer: Local sensors bring zones from low to high output when people enter and drop back after a timeout.

In this stack, no single control is trying to override all others. The top layer grants permission, daylight optimizes watts during that window, and occupancy decides when full task levels are required.

5.2 Myth to Avoid: “Any Sensor Is Better Than None”

A common misconception is that simply adding occupancy sensors automatically makes a retrofit compliant and efficient. In reality:

Poorly placed sensors in high‑bay aisles often miss forklifts in end aisles or shadows.
Over‑sensitive microwave sensors near dock doors can trigger constantly from outside motion or wind‑blown materials.
Mixed sensor types without a clear hierarchy can lead to lights cycling, which is both annoying and hard on drivers.

Experience on retrofit projects shows that misapplied sensors can erase 30–40% of the anticipated savings and generate occupant complaints that put the whole upgrade under scrutiny. Proper device selection, aiming, and commissioning matter as much as the sensor count.

5.3 Timeouts, Partial‑OFF, and Sweep Controls

Title 24 requires specific behaviors like partial‑OFF in many commercial spaces. Use a standard configuration template per space type to avoid ad‑hoc settings in the field:

Space type	Occupancy timeout	Unoccupied level	Notes
Warehouse aisles	15–20 minutes	10–20%	Longer timeout to avoid nuisance for forklift activity
Open warehouse	10–15 minutes	10–20%	Coordinate with safety and egress requirements
Offices	10 minutes	OFF or 10%	Vacancy sensors often required; confirm with Title 24 doc
Restrooms	5–10 minutes	OFF	Use vacancy or partial‑ON where required

Use a nightly or weekly “sweep‑off” from a time clock or BMS as a backstop. Title 24 expects automatic shutoff; an end‑of‑day sweep guarantees that no stuck sensor leaves a zone fully on overnight.

6. Documentation, Testing, and Passing Inspection

6.1 Build a Controls Submittal That Answers the Inspector’s Questions

Inspectors are looking for three things:

Does the design meet the letter of Title 24 for each space type?
Can the owner actually operate and maintain the system?
Are safety and code compliance for wiring and egress addressed?

A strong controls submittal typically includes:

Updated one‑line diagrams showing control devices, 0–10 V loops, and panel feeds
A space‑by‑space matrix listing:
- Space type and area
- Code‑required controls
- Actual devices and settings (timeout, partial‑OFF level, daylight thresholds)
Cut sheets for sensors, dimmers, and drivers demonstrating:
- 0–10 V capability
- Mounting height suitability
- Any relevant certifications (UL/ETL listing, FCC Part 15 compliance)

From a safety perspective, referencing the NEC role described in the NFPA 70 overview reassures inspectors that the low‑voltage control wiring has been designed with national electrical safety standards in mind.

6.2 Field Verification Checklist

Use a repeatable process when you commission and test each zone. A simple on‑site checklist:

Verify fixture counts and types per plan.
Confirm sensor locations and orientations match the layout.
Test occupancy behavior:
- Walk through each zone and confirm lights ramp from low to high.
- Confirm they return to the programmed unoccupied level after the timeout.
Test daylight response in perimeter/daylit zones:
- Artificially increase sensor illuminance (flashlight test) and confirm dimming response.
Test time‑of‑day behaviors:
- Verify sweep‑off sequences.
- Verify any after‑hours overrides function and time out per code.
Document final setpoints and record them in the O&M package.

On many retrofit projects, this level of documentation alone reduces inspection re‑visits by 50% or more, because inspectors can see exactly how the installed system aligns with Title 24 requirements.

6.3 Coordinate With Rebate and ROI Documentation

If your project is also targeting utility rebates, your controls design and documentation pull double duty. Most commercial programs look for:

DLC‑listed fixtures where required (verify in the DesignLights Consortium QPL)
LM‑79 and LM‑80/TM‑21 data for luminaires and LED packages
Evidence of automatic controls in line with energy‑code intent

The DSIRE database at dsireusa.org shows that a majority of U.S. commercial lighting incentives pay more for projects that combine high‑efficacy luminaires with controls. In California service territories, that often turns a control‑heavy Title 24 retrofit into a 2–4 year simple payback instead of 5–7 years.

For additional help connecting lumens and controls to safety and ROI in industrial spaces, see the layout guidance in Designing a High Bay Layout for Warehouse Safety and the lumen‑planning benchmarks in the Warehouse Lumens Guide for UFO High Bay Lights.

7. Industry Case Study: Title 24 Retrofit in a 30‑ft Warehouse

Consider a 60,000 ft² distribution warehouse in California with 30‑ft mounting height, previously lit by 400 W metal halide high bays on simple switch legs. The owner wants to cut energy bills and must meet Title 24 for a permit‑triggering retrofit.

Existing condition:

150 metal halide fixtures at ~450 W input each ≈ 67.5 kW connected load
No automatic shutoff; lights left on ~14 hours/day
Annual lighting energy ≈ 345,000 kWh

Retrofit design:

150 high‑efficacy LED high bays at ~200 W each ≈ 30 kW connected load
Four fixture groups per aisle, each controlled by a high‑bay sensor with 0–10 V dimming
Unoccupied level set to 15% output; 15‑minute timeout
Daylight sensors on two skylit perimeter rows
Nightly sweep‑off via existing time clock

Performance analysis:

Wattage reduction from source efficiency: ~55%
Additional savings from occupancy and daylighting: typically 20–30% based on observed run‑time reductions
Resulting annual energy use: ≈ 170,000–190,000 kWh
Overall savings vs baseline: in the 45–50% range

These values align with case studies in the DOE’s Interior Lighting Campaign final results, which report similar combined savings when high‑efficacy luminaires are paired with thoughtful controls.

From a Title 24 standpoint, this design also:

Provides multi‑level control via 0–10 V dimming
Implements occupancy‑based partial‑OFF in high‑bay zones
Captures perimeter daylight savings
Keeps a clear enable hierarchy via the time clock

All requirements are satisfied without replacing every panel or installing a full NLC platform.

8. Pro Tips and Expert Warnings for Smooth Title 24 Retrofits

Pro Tip: Use Layout Tools to Right‑Size Controls and Lumens Together

Oversizing fixtures and then dimming aggressively wastes capital budget and can create glare issues. Use photometric layout software (for example, AGi32, which relies on standard IES files per IES LM‑63) to verify light levels and beam distributions before you finalize fixture counts and control zones.

When you combine a good layout with smart zoning, you often reduce fixture counts by 10–15% and still meet both RP‑7 illuminance recommendations and Title 24 control rules.

Expert Warning: “Plug‑and‑Play” Sensors Are Not Always Plug‑and‑Play

A frequent field failure looks like this:

Contractor swaps non‑dimming LED high bays for selectable‑wattage versions.
To save time, they reuse existing line‑voltage sensors marketed as “LED‑ready.”
After energizing, fixtures either ignore the sensors, flicker at low levels, or never reach full output.

Root causes usually include:

Sensors switching line voltage only, with no 0–10 V control connection
Sensor output wiring that does not match the driver’s sinking/sourcing expectations
Selectable‑wattage drivers whose low‑end behavior is unstable with certain sensor electronics

Avoid this by:

Confirming your sensor is rated for 0–10 V dimming control and not just on/off switching.
Checking wiring diagrams carefully—some sensors need separate line‑ and low‑voltage connections.
Testing sensor + driver combinations on the bench, including low‑end dimming and power‑up behavior.

A few hours of pre‑testing routinely prevent days of troubleshooting at height and keep Title 24 inspection timelines intact.

9. Key Takeaways for California Title 24 Control Retrofits

Title 24 compliance in existing buildings hinges on controls, not just fixture efficiency.
Map space types, circuits, and control intents first; then select sensor‑ready fixtures and 0–10 V drivers that support that strategy.
Follow NEC principles for low‑voltage wiring, keep control runs short, and match sensor technology to mounting height.
Establish a clear control hierarchy so time clocks, photocells, and occupancy sensors work together, not against each other.
Commission unoccupied dim levels thoughtfully (often 10–20%) to balance savings with safety and comfort.
Build strong documentation—one‑lines, space matrices, and settings tables—to streamline Title 24 inspections and utility rebate reviews.
Use photometric and ROI tools to right‑size both lumens and controls so projects deliver predictable savings and a pragmatic payback period.

Safety & Code Compliance Disclaimer
This article is for informational purposes only and does not constitute professional engineering, electrical, or legal advice. Always consult the current California Title 24, Part 6 text, the National Electrical Code (NFPA 70), local building officials, and qualified design professionals before designing or modifying any electrical or lighting control system. Installation and commissioning should be performed by licensed electrical contractors familiar with applicable codes and standards.

Sources

Retrofitting Controls for Title 24 Compliance