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Rewiring a house: when it’s needed
Rewiring a whole house is rarely necessary. When it is, and when a more targeted fix is enough, depending on the type of wiring.
In short
This guide answers the question: does the whole house need to be rewired?
- Almost never: a full rewire is a whole other job, and it’s rarely needed.
- Rewiring is justified if the wiring is damaged, if the walls are already open, or as part of a major renovation.
- An old installation isn’t dangerous just because of its age: the danger comes from overload, wear and poorly made connections.
- In Québec, this work is reserved for electrical contractors.
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Almost never the whole house
A new panel replaces the distribution point; the circuits coming out of it stay in place. Anything non-compliant is corrected at the connection, but rewiring everything is a separate job, rarely needed.
When it’s needed
Rewiring is justified in three cases:
- the wiring is damaged;
- the walls are already open;
- a major renovation is under way.
A damaged circuit, however, is rewired.
By type of wiring
| Wiring | What we do with it | The guide |
|---|---|---|
| Aluminum (mostly homes from 1965 to 1975) | The connections are what weaken: we treat them, for much less than a rewire | Aluminum wiring |
| Knob and tube | Almost never all at once: we go zone by zone, starting with what’s covered by insulation and the most heavily loaded circuits | Knob and tube |
| Fuse panel | The panel changes; the condition of the wiring affects the bill | Fuse box replacement |
These approaches are detailed in our guides, each with its sources.
A period home rarely has 100% knob and tube anyway: successive renovations have often replaced a good part of it.
Old wiring to assess?
You get in writing what stays, what gets corrected and what gets replaced. The exact price is in the quote.
Send my quote requestHow it’s decided
At the visit, we look at the circuits your project touches, then tell you in writing which stay as they are, which need a correction and which would be worth replacing during the work.
Your insurer requires a certificate? Each one has its own requirements; once the work is done, you get a report detailing what we inspected and treated.
Selling? See Selling your house: electrical checklist.
What we do
Old wiring and troubleshooting are part of our general electrical work.
In Québec, this work is reserved for electrical contractors, even for an outlet.
The quote is written and free. If we find something when we open up, we call you before going further.
Frequently asked questions
Does an old house need to be completely rewired?
Almost never. The danger comes from overload, wear and poorly made connections, not from age alone; wiring is redone when it is damaged, when the walls are open or during a big renovation.
Does the house need rewiring when the panel is replaced?
Almost never: the new panel replaces the distribution point, and the circuits stay.
Does aluminum wiring have to be replaced?
Not necessarily: the weak point is the connections, and treating them costs a fraction of a rewire.
How much does it cost to rewire a house?
It depends on the job, the number of points and the access; the exact price is written in the quote, before the work.
Old wiring to assess?
You’ll know in writing what to keep and what to correct; the exact price is in the quote.
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Sources
The facts in this guide come from our guides linked above, each with its sources, and from the CMEQ. Consulted on October 30, 2026.