The honest answer is: less often than you’d be told by someone selling upgrades, and more often than most homeowners assume.
Here’s how to work out which side of that you’re on.
First, find out what you have
Open your electrical panel door — the door, not the cover — and look at the main breaker at the top. The number printed on it is your service size. Common numbers in Calgary homes are 60, 100 and 200.
If there’s no main breaker in the panel, or you can’t find a number, don’t go looking further. Call someone.
Rough guide by era:
- 60 amps — typically pre-1960s and long overdue. Almost any modern use case exceeds it.
- 100 amps — the standard for decades, and still the most common service we see in homes built from the 1970s through the early 2000s. Adequate for a house being used the way it was in 1995.
- 200 amps — standard in newer construction and the usual target for an upgrade.
What actually triggers an upgrade
Age alone isn’t a reason. A 100-amp service running a modest house with gas heat, gas hot water and no air conditioning may be entirely fine indefinitely.
What changes the answer is adding load. In rough order of how often we see it:
EV charging. A Level 2 charger draws continuously for hours, and the code requires it to be calculated as a continuous load. This is now the single most common reason Calgary homes outgrow their service.
Air conditioning. More Calgary homes are adding it than used to, and it lands on a service that never anticipated it.
Hot tubs. A dedicated circuit plus heating load, often on a house that also finished its basement last year.
Basement development. Lighting, outlets, sometimes a bathroom, sometimes a kitchenette. Individually small, collectively significant.
A secondary suite. Suites carry their own requirements, and capacity is usually the first thing examined.
Electric heat, a workshop, a garage with real equipment.
The signs your service is already at its limit
- Lights dim noticeably every time the furnace or air conditioner starts
- Breakers that trip under normal use — not once, but as a pattern
- You’ve started planning around the electrical: not running the dryer while the oven is on
- The panel is full, with no space for another breaker
- The panel is warm, humming, or shows rust or scorching
That last one isn’t a capacity issue. That’s a call-today issue.
What an upgrade actually involves
More than swapping a box. A service upgrade usually means a new panel, new breakers, updated grounding and bonding, frequently a new service mast and meter base, and coordination with your utility to disconnect and reconnect the service.
It’s permitted, inspected work, and it typically takes most of a working day with the power off for part of it.
→ Full detail: Panel Upgrades & Surge Protection
What you might be able to do instead
A subpanel adds circuit spaces. It does not add capacity. If you’ve simply run out of physical breaker slots but your service has headroom, a subpanel may be the cheaper right answer.
Load management for EV charging monitors total household demand and throttles or pauses the charger at peak. This often allows a charger on a service that couldn’t otherwise take one, at a fraction of the cost of an upgrade.
Nothing. Sometimes the load calculation comes back fine and the answer is that you’re worrying about a problem you don’t have. That happens more often than you’d expect.
How to actually decide
Get a load calculation. It considers your home’s size, heating type, appliances, and what you’re planning to add — and it produces a number rather than an opinion.
We do this before quoting any charger or hot tub circuit, because installing first and discovering the capacity problem afterwards is the expensive order to do things in.
Want to know where you stand? Call (403) 690-3994.