Warehouse and industrial electrical work in Ontario and the Inland Empire

Why warehouses are their own kind of electrical job

Ontario sits in the middle of the Inland Empire logistics belt. A building here can be hundreds of thousands of square feet with a few big electrical needs: a large service, a lot of lighting overhead, doors and docks that run on motors, and a growing need to charge trucks, yard tractors and forklifts. Each one runs through a different approver, so the order of the calls matters.

For the city itself, including fire alarm fees and fee tables, read the Ontario commercial page. This page covers the warehouse work that sits behind those permits.

Start with the utility

SCE supplies power in Ontario, and the utility sets the service before the building plan is final. SCE publishes an Electrical Service Requirements (ESR) manual for electrical contractors, engineers and architects. It covers the service connection equipment and wiring. Rule 16 says that, beyond the point where SCE delivers service, the applicant plans, installs, owns and maintains the facilities, and it points to Rule 2 for available voltages.

Rule 2 lists 277/480 volts among SCE’s standard distribution voltages. The voltage and size you can get depend on the lines and equipment at that address, so a given site may not offer every option. That is why the first call goes to an SCE service planner, with a load estimate and a site address. The panel and service upgrades page explains how the estimate is built.

Do not order switchgear before the utility confirms the service. A change in the service voltage or size changes the design.

High-bay LED and Title 24 controls

LED high-bay fixtures are the most common warehouse retrofit. Whether the work triggers Title 24 depends on how much of a space you change. The LED retrofit page lists the triggers and the exemptions.

When controls apply, warehouses get specific treatment. The 2025 Energy Commission compliance manual says aisle ways and open areas in warehouses need occupancy sensors that cut lighting power by at least 50 percent when the area is empty, and that each aisle must be its own control zone. Daylight controls can also apply where skylights let in enough light.

The 2025 Energy Code took effect on January 1, 2026, and the manual above is the 2025 edition. Ask the designer which edition the city is applying to your permit. Ask who signs the compliance forms.

Dock, door and equipment loads

Dock levelers, overhead door operators, dock fans and battery chargers for forklifts are many small loads that add up. They are also easy to leave off an early plan. Ask the tenant or operator for an equipment list with each item’s voltage, amps and whether it runs together with others. The load calculation uses that list. A missing item shows up later as a panel with no spare space.

Truck and fleet charging readiness

For new warehouses, CALGreen has a rule about future heavy-duty charging. Section 5.106.5.5 in the 2025 code, as summarized by the City of Santa Clarita’s checklist, requires construction that makes later installation of medium-duty and heavy-duty charging possible for new warehouses, grocery stores, retail stores, office buildings and manufacturing facilities with planned off-street loading spaces. It calls for spare raceways or busway and capacity for transformers, service panels and subpanels, sized by building size and the number of loading spaces. The goal is to avoid tearing out finished work later.

For a retrofit or tenant, charging is a separate project. SCE’s Rule 29 is an option for separately metered EV service. SCE designs, installs, owns and maintains the equipment between its distribution connection and the meter, and the applicant pays for everything on the customer side. SCE’s list of conditions includes separate metering, an EV time-of-use rate, and operating the charging equipment for at least five years. SCE offers a no-cost EV Readiness Study. Rule 29 is an alternative to Rule 16 and has no customer allowance. The commercial EV charging page covers load management and incentives.

Permits and the city counter

The City of Ontario Building Department reviews plans and inspects the work. Its page says submittals go through its online Citizen Portal Access, and the city’s resources page links an electronic submittal guide. Building permit fees are based on project valuation, and a plan review fee equal to 80 percent of the permit fee is collected when you submit. For commercial and industrial permits, the first extension request is free, and each added extension carries a $300 fee, per the city’s page. The Building Department lists 909-395-2023 for plan check and counter services.

A certificate of occupancy is issued by the city after an inspector confirms the building matches its permit and intended use, according to its FAQ. A new use or a new tenant often needs one, so put it on the schedule.

Emergency lighting and exits

A warehouse with a larger floor area and tall racks still needs exit signs and path lighting that work during an outage. The tests and the records are the owner’s job. See exit and emergency lighting for the code and the test schedule, and maintenance agreements for how owners schedule it.

What to send

Commercial electrical work in Ontario is available through the partner electrician. Send the building address and size, say if you are the tenant, owner or property manager, the existing service size if you know it, the equipment list, and what you plan to change. A photo of the main switchgear and the meter helps. Start from the commercial hub or the San Bernardino County overview.

Yard and truck court lights fall under the outdoor lighting controls on the parking lot lighting page, and sites that cannot lose power can read the commercial standby generator page. In Orange County, the Orange County commercial page lists each city’s utility and permit office.