Installing an EV charger at a house: what to plan for

Does your consumer unit have room for the extra load

A home charger typically draws between 3.7 kW and 22 kW depending on the unit and the supply available. Before anything else, look at what else is already on your consumer unit: electric heating, a sauna, a heat pump, an induction hob. Adding a charger on top of a board that is already working hard is the most common reason installations get delayed or need extra work.

Older houses in Harju county, especially those wired decades ago, often have a consumer unit sized for the appliances of that era, not for a modern all-electric household plus a charger. If the board is full, has no free circuit space, or the incoming fuse rating looks marginal, that needs sorting before the charger goes in, not after.

This is also the point to check the physical age and state of the board itself. A scorched terminal, a mix of old and new circuit breakers, or a fuse box with no earth leakage protection are signs the board needs attention regardless of the charger. Replacing a consumer unit is a fixed-price job for us, from 350 €, and it is often cheaper to do this once, properly, than to keep adding circuits to a board that is not up to it.

Do you need a three-phase supply

Single-phase supply charges at up to about 7.4 kW; three-phase allows considerably faster charging, commonly up to 11 or 22 kW depending on the charger and your network operator's connection limit. Whether you need three-phase depends on how much charging speed matters to you and what your car can actually accept — many electric cars cap their onboard charger below 11 kW regardless of what the wallbox can deliver.

If your house already has a three-phase connection, the decision is simpler: use it. If you currently have single-phase only, upgrading is a separate, larger piece of work involving the network operator, not just an internal electrical job, and it is worth confirming your daily driving and charging pattern actually needs the extra speed before going down that route.

For most households charging overnight, single-phase at 7.4 kW is enough to fully charge a typical car battery in one night. Three-phase matters more if you have two electric cars sharing one charger, or genuinely need a fast top-up during the day.

Planning the cable route from the board to the parking spot

Once capacity is settled, map the physical route the cable will take. The shortest, most direct path is usually best, but it has to avoid other services, stay accessible for future maintenance, and respect the building's structure. This is not a job for load-bearing walls, and if the route would need to pass through one, that is a stop-and-rethink point, not a drilling point.

Measure the actual distance from the consumer unit to where the charger will be mounted, including any vertical runs up or down a wall, and add a reasonable margin, since cable always needs more slack at corners and terminations than the straight-line distance suggests. Longer runs may need a larger cable cross-section to avoid voltage drop, which is a calculation worth having an electrician check rather than guessing.

Decide early whether the cable will run inside conduit in the wall, in trunking on the surface, or buried underground if it crosses open garden between the house and a detached parking area. Each choice has a different cost and a different amount of disruption, and it is easier to decide before the charger arrives than to work around a fixed mounting point afterwards.

Wall-mounted or pedestal-mounted charger

A wall-mounted charger is the simpler and cheaper option if you have a suitable wall within reach of the parking spot: house wall, garage wall, or a boundary wall close enough that the cable to the car isn't a stretch. It needs less material and less groundwork.

A pedestal or post-mounted charger makes sense when the parking spot is away from any building, for example a driveway with no adjacent wall, or when you want the charging point positioned to serve two cars parked side by side. It costs more, since it needs a footing, a post, and usually a longer cable run, but it gives more flexibility in where the car actually stands.

Either way, check the mounting height and clearance the charger manufacturer specifies, and make sure the final position leaves room to open the car's charging flap and handle the cable without it dragging on the ground or across a path where it becomes a trip hazard.

When to do it yourself and when to call an electrician

You can reasonably do the planning yourself: measuring the route, deciding on wall or pedestal mounting, checking what's on your consumer unit, and choosing the charger model. Marking out the cable route, digging a trench for an underground run, or mounting the pedestal footing are also fine to do yourself if you're comfortable with the physical work.

The connection to the consumer unit, the new circuit breaker and any earth leakage protection it needs, and the final connection at the charger itself is qualified electrician's work, done to be signed off safely. This is not a place to improvise, both because a wrongly wired charging circuit is a genuine fire and shock risk, and because getting it inspected and documented properly matters if you ever sell the house.

Our electrical work starts from 49 € per hour, with a call-out charge in Tallinn that's deducted from the bill if the job goes ahead. For anything beyond a straightforward hook-up — a consumer unit replacement, an uncertain cable run, or three-phase considerations — it's worth sending us a description or photos for a fixed quote rather than guessing at cost.

Protecting the cable outdoors and against weather

Most home charger installations involve at least some length of cable outdoors, and this is where corners get cut. Any cable run outside needs to be rated for outdoor use and protected against UV, moisture and mechanical damage — a cable simply clipped along an exterior wall without conduit will degrade faster than one properly protected, particularly through an Estonian winter of frost, thaw and road salt spray near a driveway.

Underground runs need a cable rated for direct burial or one run through purpose-made ducting, laid at a sensible depth and marked so that nobody digs into it later planting a hedge or fixing a fence post. Where the cable surfaces from the ground to reach the charger, that transition point needs sealing against water ingress.

The charger enclosure itself should carry a rating suitable for outdoor mounting, and the isolator or connection box at the consumer unit end of an external run needs similarly weatherproof housing if it sits outside. These details are inexpensive to get right at installation and troublesome to fix once the cable is buried or the charger is bolted to the wall.

• Confirm what else is on the consumer unit before adding a charger circuit
• Check whether your car and your driving pattern actually need three-phase speed
• Measure the cable route including vertical runs, and avoid load-bearing walls
• Choose wall or pedestal mounting based on where the car actually parks
• Use outdoor-rated cable and conduit, and seal any point where cable meets weather
• Leave the consumer unit connection and final wiring to a qualified electrician