When Does a House Need to Be Rewired in Calgary?

Frequent breaker trips or blown fuses

Occasional trips are normal. Frequent trips on the same circuit — especially under normal loads — indicate the wiring is undersized, damaged, or overloaded. This is a fire risk.

Flickering or dimming lights

Lights that flicker when appliances turn on, or dim and brighten on their own, suggest loose connections, undersized wiring, or a failing neutral connection. Loose connections are a leading cause of electrical fires.

Burning smell or discoloured outlets

A burning smell from outlets or switches, or outlets that are warm to the touch, discoloured, or show scorch marks, indicate arcing or overheating. This requires immediate attention.

Two-prong (ungrounded) outlets throughout the home

Homes with only two-prong outlets have ungrounded wiring. This is a safety issue and limits your ability to use modern appliances safely. Upgrading to grounded outlets typically requires rewiring.

Aluminum branch circuit wiring (1965–1975 homes)

Many Calgary homes built between 1965 and 1975 used aluminum wiring for branch circuits. Aluminum expands and contracts more than copper, causing connections to loosen over time. This is a known fire hazard. Options include full rewiring or installing CO/ALR-rated devices at every connection point.

Knob-and-tube wiring (pre-1950 homes)

Knob-and-tube wiring has no ground conductor, cannot support modern electrical loads, and the insulation degrades over time. Most insurers will not cover homes with active knob-and-tube wiring.

Home is 40+ years old with no electrical updates

Wiring insulation degrades over decades. A home that has never had electrical work done since the 1970s or earlier should be inspected by a licensed electrician.