Planning a home renovation in Ontario: a guide to the electrical side

Start with why you're renovating

Before drawings, quotes or tile samples, be clear about the goal. Are you making a kitchen work for a growing family, finishing a basement for an extra bedroom or a legal second suite, updating a dated bathroom, or getting a house ready to sell? The goal decides what's worth spending on, and it decides a lot about the electrical plan: a rental suite has different requirements from a rec room, and a cook's kitchen needs more circuits than a cosmetic refresh.

Set a realistic budget, with a contingency

Renovations come with surprises, and in older Toronto homes the electrical system is a common one. Opening a wall can reveal knob-and-tube wiring, undersized circuits or connections that aren't up to code. A contingency of 10 to 15 percent of the budget is a sensible cushion, and it's far better to have it and not need it.

The biggest electrical cost to plan for is capacity. If the renovation adds a lot of load (an induction range, a heat pump, an EV charger, a second kitchen), your home may need a panel or service upgrade. Knowing that before you finalize the budget avoids the worst kind of surprise.

Check the panel before you design

A load calculation tells you whether your existing electrical service can handle what you're adding. We look at the size of the service, the panel and what's already connected, then add the new loads. The answer is one of three: there's room; there's room if some loads are managed; or the service needs upgrading. Doing this at the design stage means the electrical plan can shape the project instead of reacting to it. Read more about permits and load calculations.

Permits and inspections: two different things

Ontario renovations often involve two separate approvals, and people mix them up:

• A building permit from your municipality covers structural changes, new rooms, plumbing and second suites. Your designer or general contractor usually handles it.
• An electrical permit (a notification of work) is filed with the Electrical Safety Authority (ESA) by the licensed electrical contractor. ESA inspects the work, usually at rough-in before walls are closed and again at the end, and issues a Certificate of Acceptance when it passes.

Skipping either can mean fines, having to open finished walls for inspection, or problems with insurance or selling the house later. We file the ESA permit and book inspections on every job that needs them.

Choose the right contractor

Look for a Licensed Electrical Contractor with a Master Electrician responsible for the work, a written quote, and a clear explanation of what's included. Check the licence number on ESA's contractor search. If a general contractor is running your project, ask who their electrician is and whether they're licensed. Our guide to hiring a licensed electrician covers what to ask.

When the electrician comes in

Electrical work happens in stages, threaded between the other trades:

1. PlanningLighting layout, outlet locations, appliance circuits and any panel work agreed with you and your designer.
2. Rough-inAfter framing and before insulation: boxes and wiring go in.
3. ESA rough-in inspectionInspected before the walls are closed.
4. Insulation and drywallOther trades close the walls.
5. FinishingFixtures, devices, appliances and final connections.
6. Final inspectionESA final inspection and the Certificate of Acceptance.

The most common delay we see is walls closed before the rough-in inspection. Booking the electrician early, and keeping them in the schedule, avoids it.

Questions to settle before work starts

• Where do you want outlets, switches and lights? Walk through each room imagining furniture and how you'll use it. Moving a box after drywall costs far more than placing it right at rough-in.
• What appliances are going in? Get the model numbers early. Ranges, ovens, cooktops, heat pumps and hot tubs each have specific electrical requirements.
• Will the panel need work? Ask for a load calculation, and get the answer in writing.
• Who files which permit? Agree who handles the building permit and who files the ESA notification.
• What's the inspection schedule? Put the ESA rough-in and final inspections on the project calendar from day one.

Room-by-room electrical checklist

Each kind of renovation has its own electrical questions. Use these as a starting point when you talk to your designer and electrician.

• Kitchen

  Dedicated circuits for the range, dishwasher, microwave and fridge; enough counter outlets with the right protection; under-cabinet and island lighting; and whether an induction range will need more capacity. See kitchen electrical.

• Bathroom

  GFCI protection, an exhaust fan sized for the room and wired to run when needed, vanity and mirror lighting, and in-floor heating if you're adding it. See bathroom electrical.

• Basement

  Lighting layout before the ceiling closes, outlets along every usable wall, a sub-panel if the suite needs its own, and interconnected smoke and carbon monoxide alarms for a second unit. See basements and legal suites.

• Addition

  Extending circuits or adding a sub-panel, exterior lighting and outlets, and checking the service has capacity for the extra space and its heating and cooling.

• Garage

  An EV-ready circuit, lighting you can actually work under, and outlets for tools. See EV chargers.

• Whole home

  Replacing old wiring while walls are open, adding surge protection, and upgrading the panel if the plan calls for it.

Plan for living through it

Even a well-run renovation is noisy and dusty. If you're living at home, ask when power will be off and for how long, especially for panel work, which usually means most of one day without power. Plan where you'll cook during a kitchen renovation, and keep a clear path to the panel. A clear timeline and a single point of contact make the whole thing much less stressful.

When the work is finished, keep the paperwork together: the ESA Certificate of Acceptance, the building permit sign-off if there was one, and any warranty documents for new equipment. You'll want them when you renew insurance, refinance or sell, and they make the next renovation easier for whoever does the work.

Over the years I have used a lot of contractors but these guys are simply the best. Full end to end service, I did not have to worry about a thing. Design, layout, permit, installation, patching, painting, etc. After completion, it was like they never had to run electrical conduits and cables throughout my house.