Plan EV charger installation before you order the building, not after the slab is poured. Where the car parks, where the electrical panel lives, and how far a conduit run has to travel all change the layout, and settling those details on paper avoids reopening a finished garage later.
This is written for anyone planning a detached garage or shop who wants charging built in from day one, not bolted on later. For the full range of garage sizes, see our garage and workshop building page.
Decide where the car parks before you decide where the panel goes
Distance between the electrical panel and the charger affects conductor size, voltage drop, conduit routing and installation work more than the charger itself does. A charger mounted a few feet from the panel is a short, simple run. A charger on the far wall of a detached building, fed from a panel across the yard, is a different job. That could require a long conduit run, trenching and additional electrical design. Decide which bay the car parks in and where the panel will sit relative to it before you finalize the floor plan. Keep that run as short and as straight as you reasonably can.
Level 1 or Level 2, in plain words
Level 1 charging uses a standard household outlet and adds range slowly, often overnight for a modest amount of driving. Level 2 charging is what most buyers actually want. It uses a dedicated 240-volt circuit, similar to an electric dryer or range, and adds range several times faster. If you are building a garage specifically to charge an EV, plan for Level 2 from the start. A dedicated circuit belongs in the electrical plan, not tacked on after the panel is already full.
What to figure out before you call anyone
A little homework before the first call saves a lot of back-and-forth later. Walk your site and answer these before you talk to an electrician or an estimator:
- Which bay or spot the car parks in, and whether that could change if you add a second vehicle
- Where your electrical panel is, or will be, relative to that spot
- Whether the space will be heated, and if not, how cold it realistically gets in a hard winter
- Whether a second EV is a real possibility within the next several years
- Whether solar is planned now or later, so an electrician can design separate or compatible conduit pathways that meet code
Bring these answers to your electrician and your estimator at the same time. The building side and the electrical side depend on the same decisions, and coordinating them once is easier than adjusting one after the other is already locked in.
Does your electrical service have room for it?
A dedicated 240-volt circuit is a real load on your electrical service. Whether your panel has room for it is a question for a licensed electrician, not a guess. If your service is already close to capacity, the electrician may need to talk to your utility before a charger circuit can go in. Ask this question early. Finding out your service needs an upgrade after the garage is finished adds a step nobody wants to repeat.
An older main panel that is already full of circuits is the most common reason this gets complicated. Sometimes the fix is a small subpanel dedicated to the garage; sometimes it is a larger service upgrade at the meter. Either is a normal, solvable problem, but it is your electrician's call to make after looking at your actual panel, not something to assume your way past.
Plan the conduit path and the wall opening with the building
A steel building's wall panels and framing are engineered before the shell goes up. The wall opening and conduit path for a charger need to be part of that plan, not a hole cut into a finished wall later. Tell your estimator you are planning for EV charging before your drawings are finalized, and show your electrician where the charger and the conduit run will go. That way the path is settled on paper, not cut into a finished wall after the fact.
While you are at it, think past the first charger. Planning approved conduit pathways for a second EV, or for a future solar connection, before the wall is closed can avoid opening finished construction later to add them.
Cold weather slows charging down
Batteries charge more slowly in cold temperatures, and charging speed depends mainly on the vehicle's own battery temperature and thermal-management system, not just the charger. Check the vehicle and charging-equipment specifications for cold-weather operation. Ask your electrician and the vehicle manufacturer whether conditioning the space would make a meaningful difference before you plan insulation and heat around it. Our insulation options guide covers what makes sense for a space you condition only part of the year.
Charger location: wall-mounted inside, or a post outside?
Most buyers mount the charger on an interior wall near where the car parks. It protects the unit from weather and keeps the run short when the panel is inside the same building. An outdoor pedestal or wall mount works too. It can make sense if the car parks outside or the panel sits on an exterior wall, but it needs a fixture rated for outdoor use and real protection from the weather. Settle this before the wall framing is finalized, since the mounting point and the conduit run both depend on it.
One more decision worth making early: a plug-in outlet or a hardwired connection. A dedicated outlet is more flexible if you change chargers or vehicles down the road. A hardwired unit is a cleaner, more permanent installation with one less connection point to fail. Either is a reasonable choice; ask your electrician which one fits your equipment and your plans.
Permits and who actually does the work
Adding a dedicated circuit and a charger is electrical work, and most jurisdictions treat it that way: a permit, an inspection, and a licensed electrician doing the wiring. Do not skip this step because the building itself is already permitted separately. Our permit guide covers the building side; the electrical permit for the charger circuit is a separate approval, usually pulled by your electrician as part of the job.
Frequently asked questions
Can I put a Level 2 charger in a detached garage?
Yes, and a detached garage is actually a common place for one. The main question is the distance from your electrical panel, since that run drives the complexity of the job. Tell your electrician where the panel sits relative to the garage before you assume the answer either way.
Do I need a permit to add an EV charger?
In most areas, yes. A dedicated circuit and a charger are electrical work, and most jurisdictions require a permit and an inspection, pulled by a licensed electrician. Check with your local building department before work begins.
How far can the charger be from the electrical panel?
There is no fixed limit, but longer runs require the electrician to evaluate conductor size, voltage drop and routing. A run under about 25 to 30 feet is generally straightforward to wire. Well beyond that, the wire and conduit sizing gets more involved, and an electrician may compare a nearby subpanel against a longer branch circuit and pick the design that fits. Those are typical, not exact figures, so ask your electrician to evaluate your actual distance. If you are building a new garage, planning the panel and the parking bay close together from the start keeps the run simple.
Does cold weather affect charging in an unheated garage?
Cold temperatures can slow charging, since speed depends mainly on the vehicle's own battery temperature and thermal-management system. An unheated garage doesn't heat the battery, so check your vehicle and charging-equipment specifications for cold-weather performance, and ask your electrician whether conditioning the space would make a meaningful difference for your equipment.
Should I plan for two EVs?
If there is any real chance of it, yes. Planning an approved conduit pathway to a second parking spot while the wall is open can avoid reopening a finished wall later. Tell your estimator now, even if the second charger itself is years away.
Tell us where the car will park, where your electrical panel sits, and whether charging starts now or down the road. Get a customized quote and an estimator will help plan the building around it, instead of working around the building later.