Title 24 & Lighting Retrofits: When an Upgrade Triggers Code

Title 24 & Lighting Retrofits: When a Lighting Upgrade Triggers Code

Plenty of contractors get surprised at permit: a "simple" lighting retrofit can pull the whole space into California's Title 24 control requirements. The good news is the rules are knowable, there are real exemptions, and wireless controls make compliance far less painful than it used to be. Here's how it works.

When a lighting retrofit triggers Title 24

Title 24, Part 6 handles lighting alterations in Section 141.0(b)2I (Altered Indoor Lighting Systems). The trigger is a percentage:

Alterations that include 10% or more of the luminaires serving an enclosed space must meet the alteration requirements.

So touch fewer than 10% of the luminaires in a space and you generally don't trip the section. Hit 10% or more, and you choose one of the compliance paths below.

The three compliance paths

When a lighting alteration triggers the section, it must comply with one of these:

  1. Meet current lighting power (Section 140.6) plus the lighting controls in Table 141.0-F.
  2. Beat lighting power by 20% — i.e., not exceed 80% of the Section 140.6 power allowance — plus the controls in Table 141.0-F.
  3. One-for-one retrofit path: a one-for-one luminaire alteration in a building or tenant space of 5,000 sq ft or less, where the altered luminaires' total wattage is at least 40% lower than before, plus the controls in Table 141.0-F.

In all three, lighting controls come along for the ride — that's the part contractors miss.

Exemptions worth knowing

Several exemptions can keep a small job out of the full requirements:

  • Single-luminaire spaces — an enclosed space with only one luminaire is exempt.
  • One-for-one, up to 50 luminaires per complete floor of the building, or per complete tenant space, per year — a practical exemption for phased or small retrofits.
  • Controls-only or lamp/ballast/driver swaps — an alteration limited to adding lighting controls, or to replacing lamps, ballasts, or drivers, is exempt from the section.
  • Acceptance testing isn't required when controls are added to 20 or fewer luminaires (the alteration may still apply — this exemption is for the testing step only).

These are the levers that decide whether your retrofit is a quick swap or a controls project — so scope the luminaire count and area early.

What controls get triggered

When the section applies, the required controls live in Table 141.0-F, and they track the same mandatory controls Title 24 requires for new work in Section 130.1 — generally manual control, multilevel/continuous dimming, automatic shutoff (occupancy or time-switch), and daylight-responsive controls where applicable. (For the detail on those control types, see our guide: California Title 24 Lighting Controls: What the 2025 Code Requires.)

You also can't go backward: alterations can't disable existing required controls or strip out functions required by Section 130.1.

Why wireless wins for retrofits

Here's the practical problem: adding occupancy sensors, daylight response, and dimming to an existing, occupied building usually means new control wiring — disruptive and expensive. Wireless lighting controls solve that:

  • Lutron Vive and Legrand Wattstopper DLM add code-required occupancy, daylight, and dimming controls without pulling new control wiring.
  • Wireless occupancy/daylight sensors (e.g., Lutron Radio Powr Savr) mount without wiring and are rated for a 10-year battery life.

That's why wireless is the default answer for Title 24 retrofits. (New to Vive? See our overview: Lutron Vive: Wireless Lighting Control for Commercial Buildings.)

Get the retrofit parts — and pro pricing

Rock Lighting & Electric is an authorized Lutron and Wattstopper dealer and distributor. We stock the wireless sensors, room controllers, dimmers, and fixtures contractors use to bring retrofits up to Title 24 — and we can help you spec the lightest-touch compliant approach. Send us the space details (luminaire count, area, what you're changing) and we'll quote it with contractor pricing.

FAQ

Does a lighting retrofit trigger Title 24?
It can. Under Section 141.0(b)2I, altering 10% or more of the luminaires serving an enclosed space triggers the alteration requirements, which include lighting controls.
What is the one-for-one luminaire alteration path?
A compliance path for one-for-one luminaire swaps in a building or tenant space of 5,000 sq ft or less, where the new luminaires' total wattage is at least 40% lower than before, plus the required controls.
Is there a small-job exemption?
Yes — a one-for-one alteration of up to 50 luminaires per complete floor or per complete tenant space, per year, is exempt, as are single-luminaire spaces and alterations limited to controls or lamp/ballast/driver replacement.
What controls does a triggered retrofit require?
The controls in Table 141.0-F, which align with Title 24's mandatory controls: manual control, multilevel/continuous dimming, automatic shutoff, and daylight-responsive controls where applicable.
How do I add controls without rewiring?
Wireless systems like Lutron Vive or Wattstopper DLM, with wireless occupancy/daylight sensors, add compliant controls without new control wiring — ideal for retrofits. Rock Lighting stocks both.

Contractor pricing and project help: create your Rock contractor account for trade pricing and online ordering, or request a quote on your retrofit. Related guides: wired vs wireless controls, Title 24 daylighting requirements, and value engineering your lighting package.

General guidance, not a compliance determination. Thresholds reflect Title 24, Part 6, Section 141.0; the 2025 code is in effect for permits filed on or after January 1, 2026. Confirm exact requirements and current thresholds for your project with a Title 24 professional and the governing code text.

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