1. Consumer unit upgrades (£180–£850)
The single biggest source of "surprise" costs. Your home EV charger needs its own dedicated RCBO (a combined RCD and circuit breaker) on the consumer unit. If your fuse board is pre-2018, plastic, or doesn't have a spare way, the installer has three options:
- Add a small enclosure next to the existing board (£180–£280)
- Swap individual breakers for RCBOs (£250–£400)
- Replace the whole consumer unit (£450–£850)
A good installer will photograph your board during the video survey and quote the right option upfront. A cheap quote that goes silent on this is almost always going to add it later.
2. Earthing arrangements (£120–£220)
Most UK homes use PME (Protective Multiple Earthing) — the earth comes through the supply cable. For EV chargers, PME has a rare but real hazard: if the supplier's neutral fails, the car's chassis can become live. Two solutions:
- A charger with a built-in PEN fault detection device (most modern smart chargers — Hypervolt, Ohme, Zappi — have this)
- Install a TT earth rod (£120–£220) — a copper rod driven into the ground next to the property
Older properties on TN-S earthing may also need a rod if the existing earth path is unreliable. The surveyor decides.
3. Cable runs over 5m (£15–£25 per metre)
Every install includes the first 5m of armoured cable from the consumer unit to the charger location. After that:
- Surface-mounted on a wall: ~£15/m
- Clipped or in trunking: ~£20/m
- Buried in conduit across a garden: ~£35–£60/m
See the detailed cable run pricing guide for examples.
4. Groundwork and pavement permits (£250–£600+)
If the cable has to cross your driveway, garden or — for properties without off-street parking — the pavement itself, you're paying for digging, ducting and reinstatement. Cross-pavement cable gullies are now permitted by some councils (Oxford, Edinburgh, Brighton) but require a permit that takes 4–8 weeks. Other councils still don't allow them.
5. Survey fees (£0–£75)
Most reputable installers do a free video survey — you walk around your house on a video call showing the fuse board, parking spot and route. Some installers, particularly for complex jobs or distant locations, charge £45–£75 for an on-site survey that's refunded against the install.
Avoid installers who quote a final price without any survey at all. That quote will change.
How to avoid the surprises
- Always do a video survey before signing.
- Ask explicitly: "Does this include consumer unit work and earth rod if needed?"
- Measure your cable run yourself before the call.
- Get at least two quotes — variation under £100 means both are honest.