Preparing Your Home for an Electric Vehicle Charger

Why a little groundwork makes a big difference

Fitting a home charge point is rarely complicated, but it does involve more than drilling a box onto the garage wall. A typical domestic installation takes a few hours, yet the jobs that run smoothly almost always have one thing in common: someone spent twenty minutes checking the basics beforehand. Supply capacity, earthing arrangements and the route your cable will take are the three areas that decide whether your installer can crack on, or whether the day ends with a phone call to your network operator and a rearranged visit.

None of this is meant to worry you. Think of it as a pre-flight check. Here is what to look at, in the order most installers would.

Start at the mains: supply capacity and your cut-out

Everything begins at your consumer unit and the main fuse ahead of it. That fuse — the cut-out — is owned by your distribution network operator (DNO), not by you or your supplier, and its rating sets the ceiling on how much power your home can draw. Many older properties still have a 60A fuse, while newer homes generally have 80A or 100A. A modern 7.4kW charge point pulls around 32A on its own, so if you arrive home, the oven goes on and the immersion heater fires up, a 60A supply can get uncomfortably close to its limit.

It is not automatically a problem. Installers can apply load management, which monitors your incoming supply and throttles the charger to keep everything within capacity. But it is worth knowing which situation you are in:

• Single-phase or three-phase? Most UK homes are single-phase. If you have three-phase, you have far more headroom and can consider faster charging.
• Looped supply? Common in terraced streets, where your cable is shared with a neighbour. This usually needs unlooping by the DNO before a charger is fitted.
• Fuse rating and meter position. Note the number on the fuse carrier and where your meter and consumer unit sit relative to where you park.
• Spare ways in the consumer unit. A dedicated circuit is the norm, so a spare slot or a small separate enclosure is handy.

If a supply upgrade is needed, your installer can usually handle the DNO application, but it adds weeks rather than hours to the timeline. Better to know early.

Earthing: the detail that catches people out

Earthing arrangements vary from street to street, and they matter enormously for charge points because the car sits outside, connected to the same metalwork as the house. Most UK properties use a TN-C-S (PME) supply, where the earth is provided by the supply neutral. On these, a fault elsewhere on the network can raise the voltage on the earthing system, which is why charge points installed on PME supplies need PEN fault detection — either built into the unit or added as a separate device that disconnects the supply if something goes wrong.

Other arrangements behave differently. A TN-S supply uses a separate earth conductor from the DNO, and a TT supply relies on an earth electrode — often a rod driven into the ground — with an RCD protecting the circuit. In each case, the requirements differ.

Two more points worth checking:

• RCD protection. Charge points need appropriate residual current protection, typically Type A with DC fault detection, or Type B where that detection is not built in.
• Existing installation condition. If your consumer unit is dated, has no RCDs, or has a mix of old and new circuits, an electrician may recommend an EICR before adding a high-load circuit. It is not bureaucracy for its own sake — it protects the whole installation.

Planning the cable route

The cable run is often the biggest variable in both cost and tidiness. Chargers need a dedicated supply, and the cable size is chosen for the distance and the load, with voltage drop kept within the limits set by BS 7671. A short run from a garage consumer unit might suit 6mm² cable; a longer run across a driveway may need 10mm² or more. Longer, thicker, or more awkward always means more time and more money.

Before your installer arrives, walk the route and note:

• Where the cable can sensibly go. Along a wall, through a garage, under a path, or up and over a doorway. Straight lines are cheaper than creative ones.
• What is in the way. Drains, gas and water pipes, decking, paving, mature shrubs, and anything you would rather not have dug up.
• Buried sections. Armoured cable is normally used outdoors and buried at an appropriate depth, with warning tape above it.
• Insulation. Cable run through loft or cavity insulation must be derated, so tell your electrician if the route passes through it.
• Any future plans. A garden office, an extension, a second charge point for a second car. Laying a slightly larger cable now is far cheaper than digging again later.

Choosing the spot — and thinking ahead

Position matters more than people expect. You want the charger close enough to reach the car's charge port without stretching the cable across a walkway, sheltered from the worst of the weather, and mounted at a sensible height — usually around 1.2 metres — so it is easy to use and read. Avoid positioning it where a car door will swing into it, and keep it clear of any future planting or bin storage.

This is also the moment to think about how you will actually use it. A dynamic load management device lets the charger share your supply rather than fight it. If you have solar panels, choose a unit that can divert surplus generation into the car. Untethered units keep the wall tidy and suit households with mixed connector types; tethered ones save you unpacking a cable every evening. Off-peak tariffs reward overnight charging, and scheduling is usually handled in the charger's app.

What to have ready for your installer

You do not need to be an electrician to make the visit productive. Photographs of your consumer unit, meter, cut-out fuse and the proposed charger location, taken in daylight, will let your installer quote accurately and flag anything that needs the DNO. Have your MPAN number to hand, note anything unusual — a looped supply, an older fuse board, a long driveway — and clear access to the meter cupboard and the route on the day. If you rent or live in a flat with allocated parking, mention it early, as grant funding and permissions work differently.

Do that, and the installation tends to be exactly what it should be: a quiet, tidy half-day's work, followed by years of waking up to a full battery.