Buying a Century Home in Toronto: Electrical Inspection Checklist

A Toronto century home is a wonderful thing to own and a genuinely different thing to buy. The bones are usually solid, but the electrical system has lived through the rise of the refrigerator, the arrival of central air, and every home-improvement trend since. When you're in a conditional offer period, the electrical is one of the areas where a couple of hours of a professional's time can save you tens of thousands — or at least tell you exactly what you're walking into. Here's the checklist we work through, and where a general home inspection stops and a licensed electrical contractor's assessment begins.

Start With the Home Inspection — Then Know Its Limits

A general home inspection is a good first pass and a reasonable condition of your offer. A competent home inspector will flag an obviously ancient panel, a 60-amp service, visible knob-and-tube in the basement, or a scary-looking octopus of extension cords. That's useful. What a home inspection is not is a circuit-level electrical evaluation by a Licensed Electrical Contractor. Home inspectors are generalists working non-destructively, and they'll be the first to write "recommend evaluation by a licensed electrician" the moment they see something they can't fully assess.

That recommendation isn't a formality — it's the signal to bring in someone who does this all day. A Portman electrical safety inspection is a focused contractor assessment: we review the service, open the panel, trace accessible wiring, and test a representative sample of devices, then hand you a written report. It's the difference between "the electrical looked old" and a documented account of what's actually there.

What Neither an Inspector Nor an Electrician Can See

Be realistic about the limits. Any pre-purchase assessment is non-destructive — nobody is opening finished plaster walls in a house you don't own yet. That means wiring concealed behind finished surfaces, splices buried in walls, and the true internal condition of old insulation stay invisible to both a home inspector and to us. We can read a great deal from the panel, the accessible runs in the basement and attic, and the devices we can pull and inspect, but we're honest that a concealed-wiring picture is inferred, not directly observed. Anyone who promises certainty about wiring behind closed walls without opening them is overselling.

Identify the Wiring by Era

The first real diagnostic question in a century home is: what am I looking at, and from when? Most Toronto century homes are a layer cake:

• Knob-and-tube (pre-1950s). Single conductors on ceramic knobs and tubes. Ungrounded, and a red flag for many insurers.
• Cloth-covered cable (mid-century). Early jacketed cable whose insulation gets brittle with age and heat. Usually ungrounded.
• Aluminum branch wiring (~1965–1975). Fine as a conductor, but connections can loosen and overheat if not properly terminated.
• Modern copper (later work). Grounded plastic-jacketed cable from renovations — the seams where it meets old wiring are where mistakes hide.

We go deep on each of these in our guide to the electrical problems common in older Toronto homes. For the two that most affect insurance and cost, see is knob-and-tube dangerous and aluminum wiring inspection and repair.

Check the Service and Panel

Two numbers matter here: the service size feeding the house and the condition of the panel distributing it. Many century homes still have a 60-amp service, sometimes with an old fuse panel. That may be fine for how the current owner lived, but if you're planning central air, a heat pump, an induction range, or an EV charger, 60 amps runs out fast. We assess whether the existing service supports your plans and what an upgrade would involve. If you're weighing it, our guides on 100-amp vs 200-amp service, fuse box vs breaker panel, and panel upgrade cost in Toronto are worth reading before you make an offer. Learning to read your panel helps you understand the report, too.

At the panel we're looking at the service rating, breaker or fuse sizing versus the wire they protect, over-fusing, double-tapped breakers, signs of overheating or scorching, the grounding and bonding, and whether the panel is a make with a known problem history. We also verify grounding on a sample of circuits — because a three-prong outlet doesn't guarantee a real ground, which we explain in why three-prong outlets don't always mean a home is grounded.

Use the Findings to Negotiate

This is where a real assessment pays for itself. A written report from a Licensed Electrical Contractor identifying a 60-amp service, active knob-and-tube, and a handful of open junction boxes is a factual, defensible basis for negotiation. You can ask the seller to reduce the price to reflect the cost of corrective work, ask them to complete specific work before closing, or simply go in with clear eyes about your first-year budget. It's a much stronger position than "the electrical seemed old," and it turns a vague worry into a line item.

Insurance Implications for Buyers

Don't leave insurance to the last minute. Many insurers ask specifically about knob-and-tube, aluminum wiring, fuse panels, and 60-amp services, and some won't bind a policy — which your lender requires to close — until certain issues are addressed. Requirements genuinely vary from one insurer to the next, so confirm with yours early, ideally while your conditions are still open. Our guides on electrical inspections for insurance and knob-and-tube and home insurance walk through what underwriters commonly ask.

Our Assessment vs an ESA Inspection

One clarification buyers always appreciate. A Portman electrical safety inspection is a contractor assessment of your home's visible and accessible electrical components, delivered as a written report. It is not an ESA inspection. An ESA inspection is a separate, provincial review of specific permitted electrical work carried out under the authority of the Electrical Safety Authority. If, after buying, you decide to upgrade the service or rewire, we file the ESA Notification of Work and coordinate the inspection, and ESA — not Portman — issues the Certificate of Acceptance once the work passes. Our ESA inspection guide explains that process, and electrician letter vs ESA certificate clears up which document you actually need.

Common Questions From Century Home Buyers