Lighting and controls
Commercial LED Lighting Retrofit
What actually drives payback, when a lamp swap is honest work, and why a Phoenix retrofit carries different controls scope than the same job in Chandler or Glendale.
An LED retrofit is three jobs sold as one: a fixture swap, a controls installation, and a branch-circuit repair nobody priced. The fixture swap is the cheap part. In Phoenix there is a fourth variable, because the city amended the 2024 IECC on the way in and deleted provisions that a straight-adoption jurisdiction still enforces. The same fixture package carries different scope on either side of a city line.
What actually drives the payback
Payback is burn hours times watts removed times what the utility charges, and most disappointing retrofits got the first number wrong. A 24-hour distribution center and a 50-hour-a-week office can carry the identical fixture and land years apart on payback. Count hours by space, not fixtures by building.
Climate is the second driver. Phoenix sits in ASHRAE and IECC Climate Zone 2B, with a cooling design dry bulb around 110°F. Every watt of interior lighting is a watt of heat the mechanical plant then has to remove, so interior reductions pay twice — once at the fixture, once at the cooling plant. Exterior lighting pays once. Split them out rather than averaging.
Third, in any space with intermittent occupancy the control is worth more than the lamp. A fixture that is off saves everything; a fixture that went from 59 W to 32 W saves less than half, and only while it runs. Warehouse aisles, stockrooms, restrooms and stairwells are where sensing and dimming carry the project.
Fourth is access. Reaching a fixture at 32 feet in an occupied warehouse, at night, on a lift, moves the number more than the fixture price does. Mounting heights, rack layout and shutdown windows belong in the estimate before anyone quotes a fixture.
Where a retrofit is the wrong call
- The lighting is already LED and only a few years old. The arithmetic rarely closes, though controls alone may still pay.
- The space is being re-tenanted inside a year. Retrofit the ceiling you will keep.
- A handful of dead ballasts in one area. That is maintenance, not a capital project.
- Lamp-only swaps into original ballasts. You will be back in the same ceiling twice.
Lamp, retrofit kit, or whole fixture
There are four honest ways to put LED into an existing commercial fixture, and they are not interchangeable. Which one is right depends on the housing, whether the lampholders are reachable, and whether the ceiling is being opened anyway.
| Method | What it is | Works where | Fails where |
|---|---|---|---|
| Ballast-compatible lamp | LED lamp runs off the existing ballast; nothing in the fixture changes | Fast relamp, no ceiling work, occupied space with no shutdown window | You keep the ballast's remaining life and its parasitic draw, and you are back in that ceiling when it fails |
| Ballast-bypass lamp | Ballast removed, lampholders re-wired, fixture relabeled as modified | Open strips and high bays where the lampholders are reachable | Single-ended and double-ended wiring must match the lamp exactly, and the fixture is now a modified assembly that has to be labeled as one |
| Listed retrofit kit | A listed driver-and-board or tube kit installed inside the existing housing | Troffers with sound housings, intact lenses and a ceiling opening worth keeping | The kit listing has to cover that specific housing, and you keep the old optics and the old distribution |
| Full luminaire replacement | New fixture, housing and all | Layout changes, ceiling already open, one warranty and one control interface wanted | Grid support and tie-off have to be right, and the new fixture count may no longer match the existing circuiting |
Two rules apply to all four. Anything that changes the fixture's internal wiring makes it a modified assembly, and it has to be labeled as one. And egress lighting and exit signs share the ceiling but are a separate scope with separate listings — count them separately and do not assume a kit covers them.
Controls, C405, and the sections Phoenix deleted
Phoenix adopted the 2024 IECC as part of the 2024 Phoenix Building Construction Code, effective 1 August 2025 under Ordinance G-7397 — and amended it on the way in. Three sections are marked Reserved and deleted in their entirety: C405.12 Automatic receptacle control, C405.13 Energy monitoring, and C405.15 Renewable energy systems. The monitoring deletion also strikes ASHRAE 90.1 Section 8.4.3; the renewable deletion also strikes ASHRAE 90.1 Section 10.5.1. Phoenix then amended C401.2.1 so the prescriptive path still lists Sections C402 through C406 and C408, and added an exception stating that compliance with C408 is optional — the justification being that commissioning happens after the certificate of occupancy issues.
In scope terms: no controlled-receptacle circuitry riding along with the lighting controls; no end-use metering package, so no submeter current transformers, no data acquisition and no reporting dashboard; no on-site renewable obligation, where base C405.15 would have called for at least 0.75 W per square foot of conditioned floor area; and no mandatory functional testing or commissioning report on the controls. Everything else in C405 still applies, in whichever edition your jurisdiction adopted.
Deleted from the code is not deleted from the job. An owner's specification, a lease, a green-building target or a rebate program can each require commissioning, metering or controlled receptacles the Phoenix code no longer asks for. We carry them when the documents call for them, and say so on the bid rather than at submittal.
| Jurisdiction | Energy code adopted | Effect on retrofit scope |
|---|---|---|
| Phoenix | 2024 IECC, effective 1 Aug 2025 (Ord. G-7397) | C405.12, C405.13 and C405.15 deleted; C408 commissioning optional |
| Chandler | 2024 IECC, Ord. 5108, plans submitted on or after 1 Jul 2025 | Adopted the 2024 text. We have not verified any C405 deletions, so assume the base requirements apply |
| Glendale | 2024 IECC, effective 9 Jan 2026 | Assume base requirements. Glendale also amends NEC 410.36(B) on tying fixtures off in a suspended ceiling |
| Mesa | 2024 I-Codes, effective 8 Jan 2026 | Base 2024 text. Downtown Mesa may also sit outside both utility rebate programs — see below |
| Scottsdale | 2021 IECC (energy provisions effective 7 Jan 2023) plus the 2021 IGCC, mandatory since 1 Jul 2023 | Older IECC text with different numbering, plus a green code almost nobody else here carries. Exterior lighting also goes to the Development Review Board |
| Unincorporated Maricopa County | 2018 IECC, adopted as optional | The energy code is not mandatory. Controls scope is driven by the owner's spec or the rebate program, not the inspector |
| Gilbert, Peoria, Tempe | Not verified from a primary source | Confirm the current edition with that city's building department before design. We will not name an edition we have not read in the ordinance |
Arizona has no statewide building or electrical code. A.R.S. Title 9 lets cities adopt codes by reference and A.R.S. §11-861 lets a county do the same, which is why two buildings across a street can be held to different editions. On a multi-site retrofit, the controls package is often not one package.
Permit, inspection and the price of night work
Electrical is a separate trade permit in Phoenix, and a retrofit almost always files as Minor commercial work — under 5,000 square feet or under $350,000 in valuation. Minor is currently the slow lane: the city's July 2026 turnaround report puts it at a 25-day goal against a 33-day average, while Major commercial averaged 30 days against a 45-day goal. Small projects are running slower than large ones. Build the schedule on 33 days.
Submittals go through SHAPE PHX, which took on commercial plan review and inspections on 27 April 2026. Plan review is 80 percent of the permit fee once valuation passes $50,000. For a small, well-defined retrofit, ask about Permits By Appointment and Permits By Inspection; for a campus with continuous work, about the Annual Facilities Program.
Night work costs more than the labor rate suggests. A Phoenix inspection within two hours either side of normal inspection hours runs $195 per hour on a two-hour minimum, so $390; outside that window, or on a weekend or holiday, the minimum is three hours, so $585. The initial inspection and the first correction re-inspection sit inside the permit fee; after that it is $195 each, including a no-access. On an occupied building, no-access is a real line item.
A.R.S. § 9-835 is worth knowing before you accept a slow review: every Arizona municipality must publish its review time frames, and the city gets one comprehensive correction request — not a running series of them.
In unincorporated Maricopa County the AHJ is county Planning & Development, working through its own Permit Center portal — and the county is two NEC cycles behind Phoenix, on the 2017 NEC.
APS and SRP rebates start with knowing who serves the building
Both APS and SRP run business energy-efficiency rebate programs, and commercial lighting is squarely what they are built for. We do not quote a rebate figure in a bid: the utility decides it, terms change with the program year, and a number the program later declines is worse than no number.
Start by establishing which utility serves the building, because the address does not tell you. SRP's own city list describes each city as served "all or in part," and APS serves parts of the same cities — Phoenix, Scottsdale, Glendale, Peoria and Avondale appear on both sides. The boundary runs through neighborhoods and in places through individual streets. Read the utility name off an existing bill, or call APS at 602-371-7171 or SRP at 602-236-8888.
One trap: the City of Mesa runs its own municipal electric utility across roughly 5.5 square miles centered on downtown Mesa, serving more than 18,000 customers. A building inside that footprint is neither an APS nor an SRP customer, and neither program applies.
After that it is paperwork discipline. SRP's published business program manual runs a May 1 to April 30 program year, with preapproval thresholds and per-site and per-customer caps written into it, so the manual you read in April is not the one governing in May. Both utilities generally want the application approved before work starts and before fixtures are ordered. We carry the fixture schedule, the wattage and quantity data and the before-and-after counts in the format asked for.
Two things we will not do: bid a rebate as a deduction from the contract price, or start a retrofit ahead of preapproval on the assumption it will come through. Both put the owner's money at risk to save a couple of weeks. To have a retrofit scoped properly first, get in touch.
Frequently asked questions
Does a commercial LED retrofit need a permit in Phoenix?
Electrical work is a separate trade permit in Phoenix, and a retrofit that changes fixture wiring, adds controls or touches branch circuits is permitted electrical work. A pure relamp where nothing but the lamp changes is generally maintenance. The practical dividing line is whether anything inside the fixture or the circuit is altered. Because retrofits usually land in the Minor commercial tier, which is currently running about 33 days against a 25-day goal, the permit is often the longest item on the schedule rather than the installation.
What did Phoenix delete from the 2024 IECC, and why does it matter for lighting?
Phoenix adopted the 2024 IECC effective 1 August 2025 under Ordinance G-7397 and deleted three sections outright: C405.12 automatic receptacle control, C405.13 energy monitoring, and C405.15 renewable energy systems. It also amended C401.2.1 to add an exception making Section C408 commissioning optional. For a lighting job, that removes the controlled-receptacle circuitry, the end-use metering and reporting package, and the mandatory functional testing and commissioning report. The rest of Section C405, including the interior and exterior lighting control requirements and the lighting power allowances, still applies.
Is a lamp-only swap ever the right answer?
Yes, in narrow cases. Where the existing ballasts are recent, the space has no available shutdown window, and the owner needs light levels improved without a capital project, a ballast-compatible lamp is honest work. What it is not is a substitute for a retrofit, because you keep the ballast's remaining life and its parasitic draw, and you will be back in that ceiling when it fails. If the ballasts are original, we would rather bypass or replace than relamp twice.
Will an APS or SRP rebate cover the job?
Both utilities run business energy-efficiency rebate programs that commercial lighting qualifies for, but neither is a blank check and we do not put a rebate number in a bid. Program terms, caps and preapproval thresholds change with the program year, and the utility makes the determination, not the contractor. Establish which utility serves the building first, because Phoenix addresses sit in both territories, then get the application approved before work starts and before fixtures are ordered.
Does a retrofit trigger the Phoenix equipment grounding conductor amendment?
It can, and this is the item that most often costs money nobody budgeted. Phoenix, unincorporated Maricopa County and Glendale all amend NEC 250.118 item 4 so that electrical metallic tubing counts as an equipment grounding path only with an additional equipment grounding conductor. Older commercial lighting circuits in the Valley frequently have no wire-type EGC pulled. Once you are working in that circuit and landing new whips, the inspector is looking at it. We check a representative sample of circuits during the walk rather than finding out at the first inspection.
Is the energy code the same across the Valley?
No, and this is the most useful thing to know before designing a multi-site retrofit. Arizona has no statewide building or electrical code, so each city and the county adopt and amend independently. Phoenix is on the 2024 IECC with three sections deleted. Chandler, Glendale and Mesa are on 2024 adoptions we have not verified as carrying those deletions. Scottsdale is on the 2021 IECC plus a mandatory green code, and unincorporated Maricopa County adopted the 2018 IECC as optional. Gilbert, Peoria and Tempe should be confirmed with each city's building department before design.
Can the work be done at night in an occupied building?
Yes, and for most retail, warehouse and healthcare spaces it is the only way to do it. Price the access honestly, because it is usually the largest cost driver. In Phoenix an inspection within two hours either side of normal inspection hours runs 195 dollars an hour with a two-hour minimum, and outside that window or on a weekend the minimum is three hours. Our posted hours are Monday to Thursday 6:00 AM to 3:00 PM and Friday 6:00 AM to 2:00 PM, so off-hours phasing is arranged as part of the schedule rather than assumed.
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