Solid aluminum wiring used for branch circuits (the outlets and switches) in many homes built roughly 1965 to 1973, when copper prices spiked. Aluminum expands, contracts, and oxidizes differently than copper, so terminations can loosen and overheat over time. (This is about branch wiring; large-gauge aluminum service entrance and feeder cable is normal and not the same concern.)
$50 to $100 per connection; $2,000 to $5,000 typical whole-home pigtail (full rewire $8,000 to $15,000+)Address before purchaseElectrical
The quick answer
Solid aluminum branch wiring was used in homes built roughly 1965 to 1973 and can loosen and overheat at the connections, a recognized fire risk, and sometimes an insurance flag. The good news: it rarely needs a full rewire. Fixing the connections (pigtailing, COPALUM, or AlumiConn) usually costs about $2,000 to $5,000 for a whole-home pigtail ($50 to $100 per connection). Have a qualified electrician assess and remediate it before you buy.
You are reading the aluminum branch wiring page. Type the year the house was built and I will tell you what else tends to be true at that age, what it costs, and what to ask. One number, ten seconds.
Free. No account. Educational and impartial, not a home inspection.
Why it matters
It's a recognized fire risk at the connections. A U.S. Consumer Product Safety Commission-funded study found homes wired with aluminum before 1972 were about 55 times more likely to have a connection reach "fire-hazard conditions" than copper-wired homes, and aluminum terminations have been known to fail without any prior warning signs. It can also be an insurance flag. The good news: it rarely needs a full rewire, properly done remediation makes it acceptable. In Ontario, ESA's position is that aluminum wiring meets code when connected and terminated to the Electrical Safety Code and the device manufacturer's instructions.
How to spot it
A 1965 to 1973 build; "AL" or "ALUMINUM" stamped on the cable sheathing at the panel or in the attic/basement; warm or discoloured switch/outlet cover plates; flickering lights not traced to a fixture or appliance; a faint burning-plastic smell at a device.
What it costs
Copper pigtailing runs about $50 to $100 per connection point; a typical 3-bedroom home has 40 to 60 points, so a whole-home remediation lands around $2,000 to $5,000 including the ESA permit and inspection. A full rewire, rarely necessary, is $8,000 to $15,000+.
What to do
Address before purchase. ESA recommends a Licensed Electrical Contractor familiar with aluminum-wiring techniques assess it, do the repairs, and have the work inspected, and not to wait for signs of overheating, since failures can be silent. Confirm coverage with your insurer/broker before removing conditions.
Education and triage, not a home inspection. Casaroo flags aluminum-wiring risk from the era and visible cable markings, a licensed electrician confirms the connections and remediates them.
Common questions
Will insurance cover a house with aluminum wiring?
Many Canadian insurers will, but they commonly want to know it has been professionally remediated, and some will ask for proof before binding a policy. Ask your broker about the specific address before your conditions come off, not after.
Do I have to rewire the whole house?
Usually not. Copper pigtailing at each connection is the standard remediation, about $50 to $100 per connection point and roughly $2,000 to $5,000 for a whole home including the ESA permit and inspection. A full rewire is rarely necessary. A licensed electrician scopes which one your house needs.
Is aluminum wiring a reason to walk away from a house?
Not on its own. It is a known, priceable remediation, which makes it a negotiation item more often than a dealbreaker. It becomes a bigger problem when the seller will not budge on price and your insurer will not bind coverage without the work done first.
Can I do the pigtailing myself?
No. Aluminum terminations need specific connectors and techniques, the work is done under an ESA permit in Ontario, and an insurer will want it done by a licensed electrical contractor. This is not a DIY item.
A licensed electrician confirms and repairs; Casaroo flags, it does not inspect.
Last reviewed 2026-07-10.
This guide is general education, not a home inspection and not advice for your specific property. Always
consult the appropriate licensed professional, and get a licensed home inspection before you remove conditions
or buy. Cost ranges are 2026 estimates that vary by region, size, and access; confirm specifics with a
qualified professional.