In Old Southwest, Grandin Village, Wasena and Raleigh Court, the garage sits at the back of the lot off the alley. It is usually 60 to 100 feet from the house panel, and in most of these properties the only power out there is one lighting circuit somebody ran decades ago on cable that was undersized then and is worse now.

That circuit was built for two bulbs and a door opener. A Level 2 charger is a continuous load pulling 32, 40, or 48 amps for hours at a time, and the conductor feeding it has to be sized for that load across the whole run. The old wire does not qualify.

Start With What Is Actually Out There

We start by finding out what is already there. We open the garage box, open the house panel, and follow the wire. What turns up is usually 14 or 12 gauge cable on a 15 or 20 amp breaker, sometimes direct buried with no conduit, sometimes spliced in a weathered box. The breaker feeding it tells you most of the story. None of it is capacity you can build a charger on, but it tells us whether the existing path can be reused.

One Circuit, or a Sub-Panel

You can run a single dedicated circuit out to the charger. It is legal and it is the smaller job. The trouble arrives two years later when you want a compressor, a welder receptacle, a mini split for the shop, or a second car, and you are paying to open the same trench twice. One properly sized feeder into a small sub-panel gives you breaker space at the garage for everything after the charger, plus a disconnect out there instead of a walk back to the house.

Voltage Drop Over Distance

Electricity loses pressure as it travels. Push current down 90 feet of conductor and the voltage arriving at the garage is lower than what left the panel. Size the wire for the amp load alone and ignore the distance, and the charger sees sagging voltage and runs warm for as long as you own it.

The fix is just wire. We calculate the drop over your measured run and step the conductor up until the loss lands in a comfortable range. On a 90 foot pull to a Wasena garage that often means a size or two above what the breaker alone would call for. Heavier wire is the cheapest insurance in the job.

Trench or Overhead, and What the Alley Allows

An overhead span across the back yard is ugly, carries clearance rules over the drive lane, and sits one limb away from a bad night. Most of these jobs go underground. That means a trench at the depth the burial method requires, and conduit rather than direct burial cable, so you can pull new conductors later without digging again.

The alley sets the routing. We keep the run on your property, not under the public alley surface, which is a separate permission and a separate repair. Gas, water, and the sewer lateral get located first. On these tight lots the clean path usually follows the fence line and enters the garage at the back corner, not the shortest line across the yard.

When There Is a Tree in the Way

A mature oak between the house and the garage costs you options. You cannot trench through a root plate without hurting the tree, and on the old trees in Old Southwest and Raleigh Court most owners will not make that trade. So the route goes around the drip line, which adds feet, which loops back to voltage drop and a heavier conductor. Sometimes we bore under the roots instead. Either way it is a call made in the yard, before anyone quotes the job.

Whether the House Service Can Carry It

None of this matters if the house service has nothing left to give. That is a load calculation, not a glance at the panel for two open slots. We add up heating and cooling, water heating, range, dryer, and general lighting and receptacle load, then measure what headroom is left. Plenty of these houses run 100 amp service, and a charger plus a shop sub-panel is a real ask of it.

Sometimes the service is fine and we pull the feeder. Sometimes the honest answer is that a panel upgrade comes first, and you hear that before you have spent anything on the garage. The charger side of the work is laid out on our Roanoke EV charger page.

Permits and Inspection Through the City

The City of Roanoke permits its own electrical work, separate from the county, and a garage feeder is permitted work. The trench gets inspected open, before backfill, which puts a hold point in the schedule worth planning around. Grounding and bonding at a detached building carry their own requirements, and that is what an unpermitted run gets wrong. We pull the permit, meet the inspector, and leave the work documented for whoever owns the house next.

Do the Feeder Once

The expensive parts of this job are the trench and the labor, not the wire. While the ditch is open, upsizing the conduit and conductors is a small share of the total, and it decides whether you get a garage that takes a charger today or a garage that also takes a shop panel, a heat source, and a second EV five years from now. We size the feeder for where you are headed.

Josh walks the run, does the load calculation, and pulls the wire himself. The person sitting across the table from you at the free quote is the person standing in the trench. Six years in, that is still how it works here.

Roanoke Garage Power FAQ

Can I use the circuit already out at the garage?

Almost never. Those runs are typically 14 or 12 gauge on a 15 or 20 amp breaker, sized for a light and an opener. A Level 2 charger needs its own circuit sized for a continuous load over the full distance to the garage.

Sub-panel or a single dedicated circuit?

If the trench is already coming out, the sub-panel is the better buy. One feeder, breaker space at the garage, and no second dig when you add lighting, a compressor, or a second car.

How deep does the trench have to be?

It depends on what you bury and what protects it. Conduit is permitted shallower than direct burial cable, and the depth also changes where vehicles cross the route. The trench is inspected open before backfill.

Does the run have to cross the alley?

We keep it on your property wherever possible. Working under a public alley surface is a separate permission with its own repair obligation, so the practical route runs along your fence line into the back corner.

Will 100 amp service handle a charger out back?

Maybe. It comes down to a load calculation against your actual heating, cooling, and appliance demand. Some houses have the headroom, some need a service upgrade first. We run the numbers before we quote the feeder.

Roanoke service area · More posts · Get pricing