Running a Dedicated Circuit to Your Garage for EV Charging

Why the route matters as much as the cable

The distance and path from your switchboard to the charger location directly affects both cost and cable sizing. A short, direct run through an accessible wall cavity is straightforward. A longer run, especially one that needs to cross outside the building or go underground to reach a detached garage, adds conduit, potentially trenching, and a larger cable to manage voltage drop over the extra distance.

Common routes for a Parramatta area home

For an attached garage, the most common route runs the new circuit through the roof space or along an internal wall cavity from the switchboard to the garage. For a carport or a garage set slightly apart from the house, the run often goes externally along an eave or wall, protected in conduit, or underground where an overhead run isn't practical or allowed.

What happens when the garage is detached from the house

A fully detached garage or a carport some distance from the main switchboard is the scenario that most affects cost, since the cable run is longer and often needs to go underground or overhead across open ground. This is worth flagging early when you're getting quotes, since a detached structure changes both the price and the installation approach compared to an attached garage. It's also worth checking whether the underground section of the run will cross any existing services, stormwater, gas, or a neighbouring boundary, since this can affect both the approach taken and the total cost.

Weatherproofing and outdoor rated components

Any part of the circuit running externally, conduit, connection points, or the charger itself if it's mounted outdoors rather than in an enclosed garage, needs to be rated for outdoor use and weather exposure. This isn't optional extra protection, it's a compliance requirement for any electrical installation exposed to the elements, and it's factored into the materials cost for an external run.

Getting it right the first time

The circuit needs to be sized for the specific charger you're installing, not just big enough for now, since undersizing it means it can't be safely upgraded later without redoing the run. This is why the electrician needs to know the charger model and its rating before the cable's selected, not after installation's already started. For how that cable size is actually calculated, see our cable sizing guide.