Permits and load calculations for EV chargers

Why EV chargers are a permit-and-paperwork job

An EV charger install looks like a simple circuit. In practice it is often the largest continuous load in the house, added to a panel that may already carry a heat pump, an electric range and a dryer. DOE's guidance for homeowners says Level 2 charging uses 240-volt equipment, that appropriate permits may be required from local building and permitting authorities, and that installations must comply with local and state codes^[1]. It also recommends safety-certified equipment installed by a certified electrical contractor^[1].

For an electrical contractor, that means three pieces of work before the install: the permit, the load calculation and the conversation about utility programs. Get them right and the job is profitable and repeatable. Skip them and you risk a failed inspection, a tripping main breaker in January or a customer who learns later that they missed an incentive.

Where the demand is

EV ownership is very uneven across the country. At the end of 2023, California had 1,256,646 registered light-duty electric vehicles, followed by Florida with 254,878 and Texas with 230,125^[2]. If you work in one of the higher-registration states, EV charging can be a steady line of work; elsewhere it is an occasional job that still deserves a standard process.

The trade is growing too. US electrical contractors employed 1,174,900 people in September 2026, up 4.5% on a year earlier^[3]. Most states require electricians to be licensed^[4], which is one reason homeowners who buy a charger online still call a contractor.

When a permit is triggered

Rules are local, but a few patterns hold across most jurisdictions. Ask your building department, and assume a permit is needed when any of these apply:

• A new branch circuit is added for the charger, which covers nearly every hard-wired Level 2 unit and most new 240-volt receptacles.
• The panel is replaced or the service size is increased.
• A subpanel is added in a garage or detached structure.
• Trenching or outdoor wiring runs to a driveway pedestal.
• A load management device or energy management system is added to keep the total load within the service rating.

Article 625 of the National Electrical Code covers electric vehicle charging equipment, and inspectors will look at it alongside the general rules for branch circuits, grounding and outdoor or garage locations. Charging is treated as a continuous load in the code, which affects how you size the breaker and conductors; check the adopted edition for the exact rule.

Running the load calculation

1. 01

   Record the service and panel

   Service size, main breaker, panel rating, available spaces and condition. Photograph the panel label and the meter.

2. 02

   List the existing loads

   Heating and cooling, water heater, range, dryer, pool or hot tub, well pump and any other large appliances. Ask about anything planned, such as a heat pump conversion.

3. 03

   Calculate the existing demand

   Use the standard dwelling calculation method from your adopted code, or, where the code allows, measured peak demand from the utility's recent history.

4. 04

   Add the charger at its intended setting

   Many Level 2 chargers can be set to a lower maximum current. The setting you configure is the load you add.

5. 05

   Compare with the service rating

   If the total stays within the rating with margin, a dedicated circuit is enough. If not, look at the options below before quoting a service upgrade.

6. 06

   Document it

   Attach the calculation to the permit application and the job file. Inspectors and future electricians will thank you.

Options when the service is tight

A load management device often saves the customer a service upgrade and gets the charger working sooner. Explain the trade-off honestly: the car may charge more slowly when the heat pump and range are running at the same time.

Utility notification and programs

Many utilities want to know about service upgrades, and some offer rebates or special rates for EV charging. DOE notes that state and utility incentives may help offset the cost of charging equipment and that some utilities offer residential time-of-use rates or other rate incentives^[1]. Check the customer's utility program page before the estimate, and keep a one-page summary for each utility you serve with program names, eligibility rules and any pre-approval steps. Some programs require approval before the install or a qualified charger model, so the order of steps matters.

Questions to ask on the first call

1. What vehicle do you have, and have you already bought a charger? Which model?
2. Where is the electrical panel, and where do you park? Roughly how far apart are they?
3. Garage, carport or driveway? Is the charger indoors or outdoors?
4. Do you have electric heat, a heat pump, an electric range, a hot tub or a pool?
5. Who is your electric utility, and are you interested in its EV programs or rates?
6. Is there a homeowners association or landlord that needs to approve the work?
7. Can you send photos of the panel with the door open and the label visible?

Panel photos before the visit let you spot a full or outdated panel and quote the right options on the first trip. If your office misses calls during install days, an AI Employee such as Ava can ask these questions and book the site visit, then pass the answers to the estimator.

Inspection-day checklist

Failed inspections on EV jobs tend to come from the same short list. Walk it before you call for inspection:

• Charger is a listed unit, and its installation manual is on site for the inspector.
• Breaker and conductor sizes match the charger's configured setting and the manufacturer's instructions.
• The charger's current setting is documented, with a photo of the switch or app screen.
• Outdoor equipment and fittings are rated for wet locations, and conduit is supported and sealed.
• Any load management device is installed per its instructions and labeled at the panel.
• The panel directory is updated with the new circuit.
• The load calculation is attached to the permit file.

Handover and follow-up

The job is not finished when the inspector leaves. Spend ten minutes with the customer and make the next call easy:

1. Show them the breaker for the charger and how to reset it.
2. Explain the current setting and what happens to charging speed if you used load management.
3. Help them set charging to start in the utility's off-peak window if they chose a time-of-use rate.
4. Leave the permit card, the panel photo and the charger manual with the job invoice.
5. Note in your records the vehicle and charger models, so you can follow up when they buy a second EV or add a heat pump.

A second EV is a common reason for a return call, and the load calculation you saved makes that quote fast.

Example: a tight 100-amp service

Example: a fictional homeowner with a 100-amp service, a gas furnace, central AC and an electric dryer buys a Level 2 charger online. The contractor's load calculation shows that adding the charger at its full setting would push the calculated demand past the service rating. Instead of a service upgrade, the contractor proposes setting the charger to a lower current and adding a listed load management device that pauses charging when the AC and dryer run together. The permit is approved, the inspection passes on the first visit and the car still charges fully overnight. The estimate also notes the utility's time-of-use rate, which the customer signs up for.