ImmoMulti — a direct buyer of plexes and income properties on the North Shore — regularly sees one obstacle derail the sale of an older triplex: outdated electrical wiring. Knob-and-tube wiring, ungrounded two-wire circuits, a fuse panel — these installations from another era are now an insurability problem. Many insurers hesitate to cover or refuse outright, and without insurance the buyer cannot finance. The result: a deal that collapses or a price negotiated down. The good news: this is a manageable problem — and it is best handled before you list.
How do you recognize outdated wiring in an older plex?
Three classic signs in an older plex: knob-and-tube wiring (wires on visible porcelain knobs in the basement or attic), two-prong outlets without grounding, and a fuse panel with screw-in glass capsules rather than breakers. All three predate the 1960s and are red flags for an insurer.
Knob-and-tube wiring was mostly installed from the early 1900s through the 1950s. It is no longer used in Canada because it no longer meets current standards or today's electrical needs. You recognize it by its individual wires strung on small porcelain knobs and threaded through ceramic tubes, often still visible in the attic or basement of a century-old plex.
Ungrounded two-wire wiring is a step newer but just as problematic: the missing ground wire increases shock risk and prevents the safe use of many modern appliances. Finally, the fuse panel — recognizable by its screw-in glass capsules — is the third major sign of an installation that was never upgraded.
According to CAA-Québec, you should check the type of wiring (copper, aluminum, etc.), especially if the building predates 1980, because this type of wiring can become dangerous as it degrades.
Source: CAA-Québec — preparing for a home insurance quote.
Why do insurers refuse to cover a plex with outdated wiring?
Because outdated wiring is associated with a higher risk of overheating and fire. Many insurers hesitate to cover a knob-and-tube property or refuse outright; others impose higher premiums and require regular inspection by a certified electrician. For a fuse panel, insurers frequently recommend replacement with a breaker panel.
The issue is first and foremost about fire safety. Because knob-and-tube wiring poses risks, many insurance companies hesitate to cover a home that has it — or refuse outright. Getting, and even renewing, home insurance then becomes much harder. When coverage is offered anyway, you will likely pay higher premiums, and the insurer may require you to have the system inspected regularly by a certified electrician as part of the contract.
The denied-claim trap
An insurance contract assumes a compliant installation. If a fire or shock occurs and the system is deemed non-compliant, the claim can be denied. In other words, even when "insured," a plex owner with outdated wiring can end up with no payout on the day it matters most.
The fuse panel follows the same logic. According to CAA-Québec, these older systems are outdated, and many insurers recommend replacing them with a breaker panel to reduce overheating and fire risks. And when the wiring is very old — the kind that runs through porcelain knobs and tubes — the insurer may outright require that a master electrician produce a certificate attesting to the general good condition of the installation.
"When the wiring is very old, such as that passing through porcelain knobs and tubes, the insurer may request that a master electrician produce a certificate attesting to the general good condition of the electrical system."
— CAA-Québec, guide to preparing for a home insurance quoteSources: YouSet — "Does insurance cover a house with knob-and-tube wiring?"; CAA-Québec.
How does outdated wiring derail financing and the sale?
A mortgage almost always requires an active home insurance policy. If the buyer of your plex cannot get coverage because of knob-and-tube wiring or a fuse panel, their financing is blocked. The deal then often collapses late in the process, or the buyer demands a price cut to cover the upgrade.
This is the domino effect income-property sellers dread. A building inspector flags the fuse box or knob-and-tube wiring during the pre-purchase inspection. The buyer's insurer then refuses to cover until the installation is upgraded. Because home insurance is mandatory with a mortgage, the lender blocks financing. The electrical upgrade becomes a condition of the transaction — negotiated under pressure, often to the seller's disadvantage.
This scenario happens often on the North Shore, where many duplexes and triplexes in established areas like Saint-Jérôme, Terrebonne or Sainte-Thérèse were built before current standards. The problem is not insurmountable — but discovered mid-sale, it costs dearly in time, negotiation and peace of mind.
What unaddressed old wiring can cost you at closing
- A narrower buyer pool (financed buyers hesitate)
- Offers conditional on the upgrade, negotiated downward
- A real risk the offer collapses for lack of insurance
- Longer timelines while your carrying costs keep running
How much does an electrical upgrade for a plex cost?
In Québec, a complete rewire of a home generally costs between $8,000 and $15,000 or more. Replacing an electrical panel (a 100 A to 200 A upgrade) runs $1,950 to $4,500 depending on complexity, with a median price of about $2,650 in 2026. For a plex, each additional unit raises the bill.
Figures vary with the scope of work, wall access and the number of units. As a guide:
| Work | Price range (QC) | Notes |
|---|---|---|
| Complete rewire | $8,000 to $15,000+ | Depends on wall access and home size |
| Panel replacement (100 A → 200 A) | $1,950 to $2,950 | Standard case; median observed ≈ $2,650 (2026) |
| Panel — complex case (FPE, aluminum, meter relocation) | $2,950 to $4,500 | Federal Pacific/Zinsco panels, aluminum service |
These amounts come from Québec renovation quote networks and serve as an order of magnitude: always get written quotes from master electricians for your specific building. Important reminder: in Québec, all residential electrical work must be performed by a holder of an RBQ electrical licence, a member of the Corporation des maîtres électriciens du Québec. Modifying a panel, adding a circuit or running a new cable into the building are not DIY jobs.
Sources: BranchéQC — electrical panel upgrade cost (2026); Soumission Rénovation — electrical renovation costs. Indicative prices; obtain quotes for your building.
Do I have to disclose outdated wiring to the buyer of my plex?
Yes. According to Éducaloi, the seller must inform the buyer of any known defect that could affect the value or use of the property, notably so the buyer can assess repair costs. Known outdated wiring must appear in the Seller's Declaration. Concealing it exposes you to a latent-defect claim after the sale.
The legal warranty of quality protects the buyer against latent defects. Wiring whose age you are aware of is not "hidden" if you disclose it — but it becomes so in the eyes of the law if you choose to stay silent. The seller must inform the buyer of defects, among other reasons so the buyer can assess the cost of renovations or repairs. Transparency is not just an obligation: it is also your best legal protection.
In practice, that means clearly stating the condition of the electrical installation in the Seller's Declaration, and keeping proof of any work done (master electrician invoices, certificate, RBQ work declaration). These documents reassure the buyer, their insurer and their lender all at once.
Source: Éducaloi — latent defects in a building.
How do you handle the electrical before selling your North Shore plex?
Two paths for the seller: have the upgrade done by a master electrician before listing (to widen the pool of financed buyers and avoid renegotiations), or sell the plex as-is to a specialized buyer who takes on the work. The right choice depends on your budget, timeline and risk tolerance.
The first option — fix it before you sell — is often the most profitable when you target the traditional market. A plex whose wiring has been upgraded, breaker panel in place and a master electrician's certificate in hand, insures without friction. The buyer gets financing, the inspection holds no nasty surprises, and you avoid the last-minute renegotiation. It is also the moment to have your electrician declare the work to the RBQ, as the regulation requires for covered installations.
The second option exists for owners who do not want — or cannot — spend $10,000 or more before a sale. ImmoMulti buys North Shore plexes and income properties in their current condition, outdated wiring included. You do not have to finance the upgrade or manage electricians: we make a direct offer that reflects the building's real condition, with no broker and no commission.
Whether you choose to renovate or sell as-is, the point is the same: do not let outdated wiring ambush you mid-transaction. Anticipated, it is a simple line item; discovered at inspection, it is a bargaining chip in the buyer's hands.
To go further, see our guide on insuring a North Shore plex in 2026 and on the pre-sale inspection of an income property.
Informational content · Does not constitute legal or tax advice. Consult a master electrician, your insurer and a notary for your specific situation.