Most building owners know California requires EV charging in new buildings. Fewer know a remodel can trigger it too. Under the 2025 California Green Building Standards Code (CALGreen), in effect since January 1, 2026, an interior project that upgrades your electrical panel can pull your parking lot into EV requirements. That can mean new conduit, panel capacity and chargers that weren’t in the budget. Here’s how the rules work, and how to spot the trigger before plan check does.
When CALGreen applies to your project
CALGreen’s nonresidential rules cover new buildings. They also cover existing buildings when the work is big enough. Under Section 301.3, that means either:
- An addition of 1,000 square feet or more.
- An alteration with a permit valuation of $200,000 or more.
Many tenant improvements and HVAC or electrical upgrades clear $200,000 easily. And as you’ll see below, parking lot work and solar carports can trigger the EV rules on their own.
The three EV triggers
The EV rules for existing buildings are in Section 5.106.5.4. They apply when any one of these happens:
| Trigger | What it looks like |
|---|---|
| A parking facility is added or altered, and the work increases power to an electric panel | Restriping or expanding a lot along with new electrical service for lighting or equipment |
| A new solar system is installed over existing parking | Solar carports |
| An addition or alteration that meets the 301.3 thresholds also increases power to an electric panel | An interior remodel or tenant improvement with a panel or service upgrade |
The third one is the one owners miss. You may never touch the parking lot. But if the project is over the threshold and adds electrical capacity, the parking can come into scope.
Exceptions worth knowing
The code lists several exceptions. They include:
- Case-by-case review by your city.
- Remote parking.
- Lighting upgrades without trenching. A parking-lot LED lighting retrofit that doesn’t involve trenching is listed as an exception.
- Emergency repairs.
That lighting exception is good news for owners planning an LED upgrade in the lot. Still, confirm it with your city before you rely on it.
What you’d have to build
Two terms come up again and again:
- EV capable. The groundwork is done so a charger can be added later: panel capacity, conduit and a planned circuit.
- EV charging station (EVCS). An actual charger, installed and working.
When the rules are triggered, the numbers apply to the parking spaces being added or altered, not the whole site. They come from the same table used for new buildings. Here are some examples:
| Parking spaces | EV capable (other than office and retail) | Chargers installed (other than office and retail) | Chargers installed (office and retail) |
|---|---|---|---|
| 10-25 | 4 | 2 | 3 |
| 26-50 | 8 | 4 | 6 |
| 51-75 | 13 | 6 | 8 |
| 76-100 | 17 | 8 | 13 |
| 101-150 | 25 | 12 | 19 |
| 151-200 | 35 | 19 | 26 |
| 201+ | 20% of spaces | 50% of EV capable | 75% of EV capable |
A few rules go with the table:
- Round up. Fractions always go to the next whole space.
- Chargers count toward EV capable. Each installed charger also counts toward the EV capable total.
- Mix charger types. Chargers can be Level 2 or DC fast, but at least one must be Level 2. Each DC fast charger reduces the required EV capable count by five.
- Build on what you have. If the lot already has some EV capable spaces, they count. You add more only if the altered area needs more than exists.
There’s also an alternative “power allocation” method. Instead of counting spaces, it sizes the requirement by total electrical capacity. That lets you choose any mix of chargers that fits the capacity.
EV spaces also have to meet accessibility rules (CBC 11B-228.3 and 11B-812), plus signage or pavement markings. Plan for them in your layout from the start.
Load management keeps panel upgrades smaller
The code allows automatic load management. This software shares available power among the cars plugged in, so each space needs less dedicated capacity. In practice, that can mean a smaller panel upgrade, or none at all.
It matters twice over here. The panel upgrade is often what triggers the EV rules. And the EV rules then add load to that same panel. Sizing both together, with load management, keeps the electrical work and the cost in check.
Other cases to know about
- Loading docks. New warehouses, grocery stores, retail, offices and manufacturing buildings with planned loading docks must also be designed for future medium- and heavy-duty truck charging. That means spare conduit and transformer or panel capacity.
- Public schools and community colleges. These projects are reviewed by the Division of the State Architect (DSA), which applies its own version of these rules. Confirm the requirements with your DSA reviewer.
- Residential. California’s AB 130 (2025) froze changes to residential building standards from October 1, 2025 to June 1, 2031. Multifamily has its own EV rules. The commercial rules above are not frozen.
Red flags that your project may trigger EV requirements
- Permit valuation at or above $200,000, or an addition of 1,000 square feet or more.
- A new panel, bigger service or new transformer anywhere in the scope.
- Any parking lot work beyond simple repairs, like expansion, reconfiguration or new electrical.
- Solar carports over existing spaces.
- Trenching in the lot for lighting, power or anything else.
- A city with a local “reach code.” Some cities adopt stricter EV rules than the state.
If you check one or more of these, raise EV charging with your design team now, not after plan check comments come back.
Who makes the final call
This article is a plain-language overview, not legal advice. The city, as the authority having jurisdiction, decides whether your project triggers the EV rules and what counts as compliance. Local reach codes can be stricter than CALGreen. Ask your building department early, especially if you’re counting on an exception.
Where to start
The best time to deal with EV requirements is before you submit for permit. EverWatt plans the panel upgrade and the parking-lot scope together, so there are no surprises at plan check. We size the system with load management to avoid service upgrades where we can, and we handle the utility applications. Utilities may cover infrastructure on their side of the meter, which can cut your cost.
Paying for it doesn’t have to be a hurdle either. If the project includes efficiency work like LED lighting or HVAC, EV chargers can ride along on PG&E On-Bill Financing.
Talk to an engineer about your remodel before it goes to permit, or read more about our EV charging services.