The honest answer first: you do not run this cable yourself. A new feed from the house panel to a separate building is designed, permitted electrical work, installed and signed off by a licensed electrician under your local code. What you control is the route the job takes — the decisions below, in the order they come up. This article deliberately contains no trenching depths, cable sizes or connection steps; those are the design itself, and they belong to the professional doing it.
Key Takeaways
- A detached-garage feed is designed, permitted work for a licensed electrician — not a homeowner cable run.
- The job runs in order: survey and load calculation, end-state decision, route design, permit, install, inspection.
- Choose the end-state — single circuit or subpanel — before the route is priced, not after.
- An existing garage outlet may remove the need for a run, once an electrician confirms its capacity and condition.
The Job in Order
| Stage | What happens | What you decide or provide |
|---|---|---|
| Survey and load calculation | The electrician checks the house panel’s spare capacity and the garage’s existing supply, if any | The charger you intend to fit, and whether more loads are coming |
| End-state decision | One dedicated circuit for the charger, or a subpanel in the garage feeding the charger and future loads | Whether the garage will ever want a second charger, lighting or workshop power |
| Route design | The electrician designs the path between the buildings to the local code | Which surfaces the route may cross, and what gets restored afterwards |
| Permit | The work is permitted where your area requires it — new feeds and subpanels typically are | Nothing, beyond keeping the paperwork |
| Installation and inspection | The run and the garage end are installed, then inspected and signed off | Access to both buildings on the day |
Two stages do the heavy lifting. The load calculation decides whether the house panel can carry the new load at all — the same assessment described in what size charger your panel can support. And the end-state decision comes before the route is priced, because a subpanel feed and a single circuit are different runs: decide the destination first, then pay for the journey once.
The Two Route Families
| Route | What it means at planning level | What shapes the job |
|---|---|---|
| Underground run | The supply crosses the yard below ground in protective conduit, as the local code specifies | What the route crosses — open lawn is a different job from paving or concrete — and who restores the surface |
| Overhead run | An aerial span between the buildings, where the local rules allow one | Clearances, attachment points and the buildings’ structure — all code matters the designer settles |
Neither route is a method a homeowner follows from an article. The electrician chooses between them from the site, the code and the buildings, and prices the surface work into the quote — the cost anatomy is in why EV charger installation is expensive and how much a home EV charger costs.
The Case Where No Run Is Needed
Some detached garages already have a 240 V outlet or a subpanel with spare capacity from earlier work. If yours does, a plug-in portable may serve with no new run at all — after an electrician confirms the existing circuit’s capacity and condition for continuous EV duty, because an old outlet’s presence says nothing about either. The EV-ACS4005T (9.6 kW, NEMA 14-50P, adjustable 16/24/32/40 A, IP66) fits that case: its current can be set to what the confirmed circuit supports. Where a new fixed installation is the answer, the EV-ACT5006T (up to 48 A, hard-wired or 14-50P, NACS, 25 ft, IP65/IP66) mounts at the garage end of whichever run is designed. Our residential charging page covers the range.
Frequently Asked Questions
Can I dig the trench myself to bring the price down?
Ask the electrician before assuming. Some are happy for the homeowner to do agreed digging to their specification; others will only sign off work they controlled end to end. Either way the design — depth, protection, materials — is theirs, and this article does not state it.
Can one run also power lights and tools in the garage?
Only if it is designed as one. A single charger circuit serves the charger; lights, outlets and a future second charger are what the subpanel end-state is for. That is why the end-state is decided before the route is designed.
Does the charger have to be inside the garage?
No — chargers in this class are rated for outdoor mounting (the EV-ACT5006T is IP65/IP66), so the unit can sit on the garage’s outer wall nearest the parking spot if that shortens the cable’s job. The position questions are in where to install a home EV charger.
Related Reading
- How Much Does a Home EV Charger Cost?
- Why Is EV Charger Installation Expensive?
- Where Should You Install a Home EV Charger?
- What Size EV Charger Can I Have at Home? Panel Capacity Explained
