Permits and load calculations · Toronto & GTA
Electrical permits and load calculations in Toronto and the GTA
The paperwork behind good electrical work: ESA permits filed correctly, load calculations that size the service properly, and the drawings and panel schedules builders and designers need.
Why the paperwork matters
Permits protect you, not just the contractor
In Ontario, most electrical work needs to be reported to the Electrical Safety Authority before it starts, and inspected when it's done. When you hire a contractor, that contractor must be licensed, and they file the notification of work. When the work passes, you receive a Certificate of Acceptance.
That certificate matters later. Insurers ask about it after claims and renewals, buyers' lawyers and home inspectors ask about it when you sell, and municipal inspectors look for it on renovations with a building permit. Work done without a permit can mean opening finished walls for inspection years later.
Two different permits
Electrical permits come from ESA. Building permits come from your municipality, such as the City of Toronto, Mississauga, Vaughan or Richmond Hill, and cover structure, fire separation and layout. Many renovations, and every legal basement suite, need both.
ESA permits for homeowners' projects
Most home projects that add or change wiring need an ESA notification: a new circuit, pot lights, an EV charger, a basement finish or a panel upgrade. When you hire us, the permit is part of our job and part of the written price. There's nothing for you to file.
If you're doing the work on your own home, ESA's homeowner rules apply, and the responsibility for the work is yours. Our guide to ESA permits in Ontario explains what needs one and how the process runs.
Know which permit
ESA permit and building permit compared
| ESA electrical permit | Municipal building permit | |
|---|---|---|
| Issued by | Electrical Safety Authority | Your municipality, such as the City of Toronto |
| Covers | Electrical installation work | Structure, fire safety, layout, plumbing and more |
| Who files | The Licensed Electrical Contractor (or a homeowner doing their own work) | The owner, designer or general contractor |
| Inspection | ESA inspector, rough-in and final as needed | Municipal building inspector at set stages |
| At the end | Certificate of Acceptance | Permit closed after final inspection |
Sizing the service
Load calculations, done properly
A load calculation answers a simple question: how much power will this home or building need? The answer decides the service size, the panel and the main breaker. Too small and breakers trip, or you can't add the EV charger or heat pump you planned. Too large and you've spent money on capacity you'll never use.
We calculate from real inputs: floor area, heating and cooling equipment, cooking appliances, laundry, water heating, EV chargers, pools, hot tubs and suites. It's the basis for every panel upgrade we quote, and for the service on every new build we wire.
Drawings and documentation
Builders and designers often need more than a number. We prepare electrical layouts, panel schedules and single-line diagrams for permit sets and for the site, and work with certified electrical engineers where a project requires sealed drawings. For commercial projects and multi-unit buildings, engineering is more often part of the scope.
Adding an EV charger
Will the existing service carry it, or is an upgrade or load management needed?
Planning a basement suite
Two households on one service need to be calculated together.
Switching to a heat pump
Electric heating and cooling can change the picture significantly.
Building new
The service is sized once, for the life of the house.
How it works
How we handle the paperwork
Review the scope
Drawings, appliance lists or a site visit.
Load calculation
Service and panel sized to the real load.
Drawings if needed
Layouts, panel schedules, single-line diagrams, with engineers where required.
Permit
ESA notification filed before work starts.
Inspections and certificate
ESA inspections booked, and the Certificate of Acceptance at the end.
Questions
Permits and load calculations: common questions
Can a homeowner take out their own electrical permit?
In Ontario, homeowners can do some electrical work on their own home and take out the permit themselves, with conditions. When you hire someone, they must be a Licensed Electrical Contractor, and the contractor files the permit. That's what we do on every job that needs one.
What is a load calculation?
It's a calculation, following the method in the electrical code, that estimates how much power a home or building needs based on its size and what's connected: heating, cooling, cooking, an EV charger, a hot tub. It tells you what size service and panel you need.
Do I need an engineer for my project?
Most houses and renovations don't. Larger or more complex projects, and some commercial work, require drawings sealed by a professional engineer. We work with certified electrical engineers when a project calls for it.
Can you help with a load calculation for a basement suite or EV charger?
Yes, these are among the most common reasons we do one. The calculation shows whether the existing service can take the new load or whether an upgrade or load management is needed.
Do you take out the ESA permit?
Yes. In Ontario, the licensed contractor files the notification of work with the Electrical Safety Authority (ESA) and books the inspection. We handle it on every job that needs one, and you get the ESA Certificate of Acceptance when the work passes. Keep it: insurers and home buyers often ask for it.
Where we work
Permits and load calculations across the GTA
We serve homeowners, builders and businesses across Toronto and the GTA.
- North York
- Toronto
- Forest Hill
- Etobicoke
- Scarborough
- Mississauga
- Vaughan
- Richmond Hill
- Oakville
- Caledon
- King
- Barrie
- Markham
- Aurora
- Newmarket
- Brampton
- Alliston
- Wasaga Beach
- Collingwood