Question 1

Do I need an ESA permit to rewire a room in my house?

Accepted Answer

Yes, an ESA permit is required any time you add, extend, or replace electrical wiring in Ontario — including rewiring a single room. This isn't optional or a suggestion; it's a legal requirement under Ontario's Electricity Act, and skipping the permit creates serious problems for your home's insurability and resale value.

When your electrician rewires a room, they're running new NMD90 cable from the panel to new or existing outlet and switch locations, installing new electrical boxes, and makin

Question 2

How do electricians run new wires through finished walls without tearing everything apart?

Accepted Answer

Experienced electricians use a combination of fish tapes, flex drill bits, access holes at strategic points, and creative routing through attics and basements to run new wire through finished walls with minimal damage. It's one of the skills that separates a seasoned residential electrician from someone who learned on new construction, and it's especially important in Toronto's older housing stock where plaster walls and complex framing make the job more challenging.

The basic technique starts

Question 3

What are the costs and benefits of upgrading from 60 amp to 200 amp service when rewiring?

Accepted Answer

Upgrading from 60A to 200A service during a rewire is one of the best investments you can make in an older GTA home, typically adding $3,500 to $5,000 to the rewiring cost but future-proofing your electrical system for decades. If you're already paying for a rewire, bundling the service upgrade saves money compared to doing it as a separate project later.

A 60A service was adequate when your home was built — when the heaviest electrical loads were a refrigerator, a few light bulbs, and maybe a

Question 4

Is it safe to live in my house while the wiring is being replaced?

Accepted Answer

Yes, most GTA homeowners stay in their homes during a rewire, and a good electrician will stage the work so you always have power to essential areas like the kitchen, bathroom, and at least one bedroom. That said, there's real disruption involved, and understanding what to expect helps you decide whether to stay or temporarily relocate.

During a rewire, your electrician works through the home section by section, turning off power to one area at a time while running new NMD90 cable and installin

Question 5

What's the difference between upgrading my panel and rewiring my whole house?

Accepted Answer

A panel upgrade replaces your electrical panel (the breaker box) with a higher-capacity one, while a rewire replaces the actual wires running through your walls — they're two completely different projects that address different problems, though they're often done together. Understanding the distinction helps you avoid paying for work you don't need, or worse, skipping work that you do.

A panel upgrade is about capacity and safety at the distribution point. If you have a 60A or 100A panel and ne

Question 6

Can I get home insurance with knob-and-tube wiring in Toronto?

Accepted Answer

Getting home insurance with active knob-and-tube wiring in Toronto is increasingly difficult, and many major insurers will either decline coverage entirely or charge significantly higher premiums with restricted terms. If you're buying a century home in neighbourhoods like the Annex, Cabbagetown, Riverdale, or High Park, the insurance question is something you need to address early in the process.

Most mainstream Ontario insurers — the ones you see advertised on television — have tightened thei

Question 7

Is it more cost-effective to rewire my entire house or just upgrade specific circuits during a renovation?

Accepted Answer

Whether to do a full rewire or targeted circuit upgrades depends on the age and condition of your existing wiring, the scope of your renovation, and your budget — but if your home still has knob-and-tube or aluminum wiring, a full rewire during a major renovation is almost always the smarter long-term investment. Walls are already open during renovation, which dramatically reduces the labour cost of rewiring compared to doing it as a standalone project.

If your home was built before 1945 and ha

Question 8

What is NMD90 wire and why does my electrician keep mentioning it?

Accepted Answer

NMD90 is the standard residential electrical cable used in Ontario homes, and your electrician mentions it because it's the wire going into your walls for virtually every circuit in a modern Canadian home. The name stands for Non-Metallic Dry 90°C — meaning it has a non-metallic (plastic) outer sheath, is rated for dry locations, and the conductor insulation can handle temperatures up to 90 degrees Celsius.

Inside that plastic outer jacket, NMD90 contains two or three insulated copper conductor

Question 9

What does a whole-home rewire actually involve and how long does it take?

Accepted Answer

A whole-home rewire involves replacing all existing electrical wiring, outlets, switches, and often the panel with modern code-compliant materials, and typically takes one to two weeks for an average GTA home. The scope depends on your home's size, number of circuits, wall accessibility, and whether you're keeping the existing panel or upgrading it as part of the project.

The process generally starts with your electrician performing a thorough assessment of the existing wiring — identifying wha

Question 10

How much does aluminum wiring remediation cost in the GTA and is it worth it?

Accepted Answer

Aluminum wiring remediation in the GTA typically costs between $3,000 and $12,000 depending on the method used and the size of your home, and yes, it is absolutely worth it for both safety and insurance reasons. The two main approaches — AlumiConn connectors and COPALUM connectors — differ significantly in cost, and the right choice depends on your budget and long-term plans for the home.

AlumiConn connectors are the more affordable option, generally running $3,000 to $8,000 for a typical Scarb

Wiring & Rewiring