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Buying an older home in Galt or Preston? What an electrical inspection should cover before you close

A home inspection is not an electrical assessment. ESA's advice to buyers is to have a Licensed Electrical Contractor assess the home's electrical system, and to have your lawyer request a Search of Records from ESA before closing, because by law the buyer takes on any outstanding notifications to correct defects.

Last updated October 24, 2026 · Reviewed by the Cambridge Electricians team

Is a home inspection enough for the electrical?

No. A home inspector looks at the whole house in a few hours and reports what is visible; the Electrical Safety Authority points out that an assessment by a Licensed Electrical Contractor is different from a home inspection because it focuses only on the electrical. In a stone house on Dickson Hill or a brick semi off King Street in Preston, the parts that matter are above plaster ceilings, inside a basement that has three generations of panels on one wall, and in the attic under blown-in insulation. A general inspection will flag a fuse panel and a few open splices. It will not tell you how many circuits are still live on knob-and-tube or whether the house still has a working ground.

Ask ESA for a Search of Records before closing

This is the step most Cambridge buyers do not know about. ESA keeps a record of every electrical notification filed at an address since 2000. Two things in that record matter to a buyer:

• Outstanding notifications. If a previous owner's electrician filed a notification and ESA issued a defect notice that was never cleared, the file is still open. ESA states that by law the buyer assumes responsibility for correcting those defects.
• Work with no notification at all. A finished basement or a new kitchen with nothing on file means the wiring was never reviewed by ESA.

ESA's guidance is to have your lawyer request a Search of Records from ESA as part of the purchase agreement. If you have already closed, the equivalent is an Access to Information request, which reports all electrical work completed with an ESA notification. Both carry a fee. When a seller says the basement was done properly, the Certificate of Acceptance is the document that proves it; ESA says you can ask the contractor who filed the notification for a copy or call ESA to request one.

What the assessment looks at in a Cambridge century home

The contractor we book for Galt, Preston and Hespeler does the assessment ESA describes, which is a review of the home's wiring and devices to identify hazards that could lead to fire or shock. In an older house the checklist runs roughly like this:

1. The service and panel. Fuses or breakers, amperage, how many panels are chained together, heat discolouration, doubled-up breakers, and whether the grounding still works. Many old Cambridge houses were grounded to a lead or galvanized water service that has since been replaced with plastic.
2. What is live on knob-and-tube. Tracing which circuits still run on the original wiring, opening accessible junction points in the attic and basement, and checking for insulation over the conductors and for splices made outside boxes.
3. Aluminum terminations in houses from the mid-1960s to late 1970s, which in Cambridge means Preston Heights, east Galt and north Hespeler.
4. Grounding and GFCI protection at kitchen counters, bathrooms and outdoors, reversed polarity and open grounds on three-prong receptacles.
5. Renovation work with no record at ESA: the basement bathroom, the added kitchen, the extension cord that has become permanent wiring.

You get the findings in writing with photographs and the options priced, which is a document you can take into a negotiation.

Knob-and-tube, aluminum and the insurer

Expect the insurance question before the closing date. ESA says knob-and-tube wiring is safe provided it is properly maintained by a Licensed Electrical Contractor, and in the same guidance that many insurers will not provide or renew coverage on homes with it, and some may require replacement first. On aluminum, ESA says the wiring is safe with proper terminations and approved devices, and that some insurers will not provide or renew coverage without an ESA inspection and may ask for the Certificate of Acceptance. Call your insurer or broker before you waive conditions and ask exactly what they need. The assessment can be written to answer that question.

Fixing what is found

If the assessment turns up deficiencies, ESA says a separate notification of work must be filed by whoever does the repairs, which in a hired job means the Licensed Electrical Contractor. The contractor files it under their licence, ESA reviews the work, and ESA issues the Certificate of Acceptance. The scope ranges from re-terminating aluminum connections through the existing boxes, to a partial rewire of the floor that carries the load, to a full 200-amp service replacing a fuse block. The knob-and-tube and aluminum remediation page describes each.

What this means for your offer

Book the assessment during your inspection period, order the Search of Records through your lawyer, and ask the insurer what they require, all before conditions come off. If the house needs a service upgrade or a partial rewire, the written quote gives you a figure to negotiate with rather than a guess. The Cambridge electrician cost guide explains what moves the number in a century home, and you can send the listing and the inspection report to have the contractor call you back before your deadline.

Sources

• Buying a Renovated Home - Electrical Safety Authority
• Buying a Home - Electrical Safety Authority
• Electrical System Safety Assessment - Electrical Safety Authority
• Knob and Tube Wiring - Electrical Safety Authority
• Aluminum Wiring - Electrical Safety Authority