A wallbox in a new build: what to prepare during construction

The short answer

Even if you don't have the car yet, have the builders run the cable, or at least a conduit, from the consumer unit to where the car will park, and reserve space in the consumer unit. The wallbox then just gets mounted and connected.

1. A cable to the parking spot

The most expensive part of a later installation is usually the cable route — drilling, chasing, trunking or a trench across the garden. During construction it's a few extra metres of cable.

• For an 11 kW wallbox the usual choice is a five-core cable with a 6 mm² cross-section. The electrician sets the exact size by route length — longer runs need a heavier cable.
• If you don't want to run the cable yet, at least lay a conduit of sufficient diameter. The cable can be pulled through later without any demolition.
• End it where the wallbox will be: on the garage wall, by the driveway, or at the spot where a pedestal will stand.

2. Space in the consumer unit

A wallbox needs its own circuit breaker and residual current device. Leave free slots in the consumer unit so it doesn't have to be extended or replaced later.

Think about dynamic load management too: the wallbox then measures the whole house on the main supply. It helps to have room for that metering in advance.

3. The right main breaker from day one

For a new build you apply to the grid operator for a connection and choose the main breaker rating anyway. That's the best moment to account for an EV — upgrading later means another request and another fee.

For an 11 kW wallbox alone, 3×25 A is usually enough, especially with load management. If you're also planning a heat pump or an induction hob, have it calculated. More in is a 3×25 A main breaker enough?

4. Internet connection

Smart wallboxes run through an app, can charge from solar surplus and track consumption. They need Wi-Fi or a network cable. Wi-Fi is often weak in a garage — a data cable in the same conduit costs next to nothing.

5. Solar panels

If you're building with solar, plan it together with the wallbox. Charging from surplus is the cheapest electricity your car will ever get. More in wallbox and solar.

How we do it

If you're still building, we're happy to look at the electrical plans or visit the site and tell you where to run the cable and what to leave ready. We then install the wallbox once you have the car.