Adding a subpanel to a garage gives you expanded electrical capacity for workshops, EV chargers, lighting, and dedicated circuits — without overloading your main panel. Here is what garage subpanel installation costs in Ontario and what the project involves.
Installing a subpanel in a garage in Ontario starts at $600. The ESA permit and inspection are additional. The final cost depends on the panel size (amps), the distance from the main panel to the garage, and whether the wiring runs overhead, underground, or through finished spaces.
A subpanel (also called a secondary panel or distribution panel) is a smaller electrical panel fed by a circuit from the main panel. It distributes power locally — in this case, inside the garage — allowing you to add multiple circuits without running individual wires back to the house panel for each one.
Common reasons to add a garage subpanel include:
Subpanels are typically sized at 60, 100, or 125 amps depending on the planned load. A larger panel requires heavier feeder wire and a larger main breaker — increasing material and labour cost. Your licensed electrician will recommend a size based on what you plan to run in the garage now and in the future.
The distance from the main panel in the house to the garage determines how much feeder wire is needed. Wiring can run through the attic, underground in conduit, or along the exterior of the house — each route has different labour and material requirements. Underground runs through a driveway or landscaped area add trenching cost.
Adding a subpanel requires a spare double-pole breaker slot in the main panel to accommodate the feeder breaker. If the main panel is full or has insufficient capacity for the additional load, a panel upgrade may be required before the subpanel can be installed — quoted separately.
Yes. Installing a subpanel involves regulated electrical work under the Ontario Electrical Safety Code (OESC) and requires an ESA permit. The Electrical Safety Authority will inspect the feeder wiring and panel installation after the work is complete.
Only a licensed electrical contractor can legally pull the ESA permit and perform the work. In Ontario, all residential electrical work — including subpanel installation — must be done by a licensed electrical contractor or master electrician.
EZSMART installs subpanels for garages and detached structures across Ontario. We assess the main panel capacity, planned garage load, and feeder route before providing a complete price. ESA permit and inspection are coordinated as part of the installation.
Contact us today to get a quote for your garage subpanel project.
Electrician Since 2008 Journeyman Electrician Designated Master Electrician at EZSMART Corp