Start with the real question
The question is not "how many amps is my panel?" It is "how much of my service is actually being used?" Those are different questions, and confusing them is why some homeowners are quoted a service upgrade they do not need.
A 100-amp service in a home with gas heat, a gas water heater, a gas range and a gas dryer is carrying far less load than a 100-amp service in an all-electric home. The panel label is the same. The available headroom is not remotely the same.
How Ontario decides
Home EV charging is governed by the Ontario Electrical Safety Code, currently the 2024 edition (29th), in effect since 1 May 2025. Section 8 of the Code governs load calculations and Section 86 governs electric vehicle charging systems specifically.
There are three routes to a compliant installation, and only one of them is a service upgrade.
Route 1 — the standard calculated load
The contractor runs the conventional calculation for your home: floor area, heating type, range, water heater, and so on, plus the charger as a continuous load. If the total fits inside your service rating, you are done. Nothing needs upgrading and the job is a straightforward install.
For a great many gas-heated GTA homes on 100 amps, this is the outcome — and it is why we always ask before assuming.
Route 2 — demonstrated actual load
The Code permits the installer to determine whether a service can accept EV charging equipment based on your home's demonstrated or measured actual load rather than the default calculation, which tends to be conservative. In practice this can mean reviewing your real consumption data or metering the service.
This route rescues a meaningful number of homes that fail the default calculation on paper but have obvious real-world headroom.
Route 3 — an EVEMS (load management)
This is the one most homeowners have never heard of, and it is often the cheapest good answer.
An Electric Vehicle Energy Management System monitors your electrical load and automatically throttles or pauses the charger when the rest of the house is drawing heavily. Because the charger can no longer contribute an uncontrolled peak, the Code treats its demand differently: where an EVEMS limits the charger, the demand load is limited to what the EVEMS allows, and where the EVEMS monitors the service and feeders, the charger's load need not be counted in the calculation at all.
The practical effect is that a device costing a few hundred dollars can replace a service upgrade costing several thousand. The trade-off is real but usually minor: on the rare evening when your dryer, oven and air conditioner are all running, the car charges more slowly for a while. Most people never notice, because most people charge overnight when the house is asleep.
Ask about this specifically. If a contractor tells you a service upgrade is the only option, it is entirely fair to ask whether an EVEMS or a demonstrated-load calculation has been considered. Whether either applies to your home is a judgement only a licensed electrical contractor can make and sign off on — but you are entitled to have the question asked.
When you genuinely do need an upgrade
Sometimes the answer really is a service upgrade, and pretending otherwise wastes everyone's time. The usual cases:
- The home is all-electric — electric furnace or baseboards, electric water heater, electric range — and is already close to capacity
- The existing panel is physically full, with no space for new breakers and no room for a subpanel
- The panel is an obsolete or recalled type that no longer accepts new breakers safely
- The service entrance, mast or meter base is deteriorated and needs attention regardless of the charger
- You are stacking several new electrical loads at once — a charger plus a heat pump plus an induction range, for example
That last case is worth thinking about strategically. If a heat pump is anywhere in your plans, doing the service upgrade once, now, is usually cheaper than doing two separate projects two years apart.
What a service upgrade involves
More than swapping a box. Typically: a new panel, a new service entrance cable, a new meter base, coordination with your local distribution company to disconnect and reconnect, an ESA notification of work, and inspection. It is a day or more of work with a power interruption in the middle.
Your distributor depends on where you live, which matters because they control the disconnect and reconnect scheduling:
| Area | Local distribution company |
|---|---|
| Toronto — including North York, Scarborough, Etobicoke | Toronto Hydro |
| Mississauga, Brampton, Vaughan, Markham, Richmond Hill | Alectra Utilities |
| Oakville | Oakville Hydro |
| Burlington | Burlington Hydro |
| Ajax, Pickering, Whitby | Elexicon Energy |
A small number of properties near municipal boundaries are served by Hydro One instead, so it is worth confirming rather than assuming.
The paperwork, and why it matters
For any of these routes, a notification of work is filed with the Electrical Safety Authority before the work begins. When the installation passes review, ESA issues a Certificate of Acceptance to whoever filed the notification.
Keep it. It is the document that answers the insurer's question after any electrical incident, and the buyer's lawyer's question when you sell. An unpermitted panel change is a genuine problem to inherit, and it is the kind of thing that surfaces at the worst possible moment.
Common questions
How do I find out what my panel can take without paying for a survey?
Two things you can check yourself in a minute. Look at the main breaker at the top of your panel — it will be stamped 60, 100, 125, 200 or 400. Then take stock of what in your home runs on electricity rather than gas: heat, water heater, range, dryer. A 200-amp service is very likely fine. A 100-amp service with mostly gas appliances is often fine. A 100-amp service running electric heat is the case that needs a real calculation.
Is a subpanel a cheaper alternative to a service upgrade?
A subpanel solves a space problem, not a capacity problem. If your panel is physically full but your service has headroom, a subpanel is a sensible and economical fix. If your service itself is maxed out, adding a subpanel changes nothing about the underlying limit.
Will load management make my car charge too slowly to be useful?
Almost certainly not. A Level 2 charger typically adds somewhere in the range of 30 to 50 kilometres of range per hour, and a car plugged in overnight has eight or more hours available. Even with the charger throttled during the evening peak, most drivers wake up to a full battery. The people for whom this is genuinely tight are high-mileage drivers with a short charging window — and that is a conversation to have before choosing the approach, not after.
Can I upgrade the panel now and add the charger later?
Yes, and if you are already renovating or already have the walls open, the timing argument is strong. Just be aware that a panel upgrade on its own attracts no rebate in Ontario, so there is no incentive-driven reason to rush it.
About this page. Oryn coordinates home EV charger installations across the Greater Toronto Area, Hamilton, Niagara and elsewhere in Ontario. The electrical work is performed and certified by independent, ECRA/ESA-licensed electrical contractors — Oryn is not itself an electrical contractor. Prices described here are general market ranges for orientation only, not a quote, and not an offer. Your own price depends on your home and is confirmed in writing before any work starts. The charger installation — the wiring from your panel to the charger, and the charger itself — is quoted as a fixed price. Electrical panel or service work, where it is needed, is quoted separately as an estimate with a stated ceiling that you approve before anything begins.