What to gather before a home EV charging assessment

Why the panel label cannot answer the whole question

The number on a panel does not tell you how much capacity is available for an additional load. The electrician needs to assess the electrical service supplying the home, the loads already connected and the proposed charging equipment together.

BC Hydro’s electrical-capacity guidance explains how a load calculation considers a home’s existing electricity needs against its service capacity. It also describes energy management as a possible alternative to a service upgrade. That is background on assessment principles; its utility-data process and BC requirements should not be assumed to apply in Calgary.

The City of Calgary’s electrical guidance addresses capacity checks when adding EV charging and describes energy management systems that control electrical loads. Shared services can add another constraint. An assessment needs to establish what applies to your property before recommending equipment or changes.

Your preparation checklist

Make a short note with the items below. Leave anything you cannot identify as unknown. Take photos only from safely accessible positions; keep covers in place and leave electrical inspection and measurements to the electrician.

1. Vehicle and charger details

   Record the vehicle make, model and year, including any second EV you expect to charge. If you already own or are considering a charger, save its exact model and manufacturer’s product information. Say whether it is purchased or still a possibility.

   Include your usual daily driving and the hours the car is normally parked at home. Ask the electrician how the proposed charging arrangement fits that routine before settling on equipment.

2. Parking and possible cable route

   Photograph the parking space, the vehicle’s charging-port position and the wall where you would like the charger. Include a wider view showing doors, walkways and storage that could affect placement.

   Note whether the garage is attached or detached. Photos of accessible spaces between the panel area and parking spot help explain the layout. Mark finished walls and any planned renovations; let the electrician determine a suitable wiring route. BC Hydro’s installation overview also identifies charger location near parking as a planning decision.

3. Panel identification

   Take a photo of the closed panel and its surroundings. Record any manufacturer or model information readable without removing a cover, along with the panel’s location. Mention a separate garage panel if you know one exists. Existing electrical drawings or past installation paperwork may also be useful.

   If a label is hidden or unclear, leave it for the visit. A photo helps identify equipment; it cannot confirm that the installation is suitable for a new charger.

4. Existing and anticipated loads

   List major equipment such as electric heating, a heat pump, air conditioning, a range, dryer, water heater or hot tub. Include model details from paperwork if available. Note plans for another EV, a suite, workshop equipment, solar or battery storage, with an approximate sequence if known.

   Separate equipment already installed from future ideas. Ask which information the electrician needs for the assessment and whether any utility records would help; do not try to calculate spare capacity yourself.

Questions to bring to the assessment

• What limits charging at this property: the service, existing loads, equipment or installation route?
• Is the proposed charger suitable, and what still needs checking?
• If capacity is constrained, is energy management appropriate, or is other electrical work needed?
• How would any proposed load control affect charging while other equipment runs?
• Who will confirm the applicable permits, inspections and any utility or property approvals?

Tell the electrician if you rent, have shared parking or live in a condominium or rowhouse. Calgary’s guidance distinguishes shared electrical services from individual services. Ask what building information or owner involvement is needed before agreeing to the work.