Home Charging
Consumer Unit Upgrade for an EV Charger: When and How Much
A consumer unit upgrade for an EV charger isn't always needed. When a spare way is enough, when a new fuse box is required, and typical UK costs explained.
By Evova · Published
Often, no — most homes don’t need a new consumer unit (fuse box) to have an EV charger installed. If your board is reasonably modern and has a spare way — an unused slot — the charger’s dedicated circuit can usually go straight in. Where it can’t, a small separate unit next to the meter is often cheaper than replacing the whole board — trade research (MyJobQuote, 2026) puts a full replacement at £350–£750, while the small unit itself costs only around £30–£40 plus fitting. Either way, the installer you choose will check your supply and consumer unit as part of the quote, so you don’t need to diagnose any of this before you request a quote.
When a spare way is enough — and when it isn’t
A 7kW home charger needs its own dedicated circuit back to the consumer unit — it can’t share with the cooker or a ring of sockets. That circuit draws around 32A, so it gets its own protective device.
For a spare way to work, two things must be true. There has to be physical space in the board, and the circuit must meet the current wiring regulations (BS 7671): every home charging point needs its own 30mA RCD of Type A, F or B. Type A or F is only acceptable where the charger itself detects DC fault currents — which most modern chargers do — and some chargers build the whole RCD in, simplifying the board work further.
Where it falls down is older boards. If your consumer unit is full, or it’s an old rewireable-fuse type with no RCD protection, many installers won’t extend it. That still doesn’t force a full replacement: a common fix is a small separate consumer unit fed directly from the meter position, dedicated to the charger. If your property is older, our guide to EV charger installation in older homes covers the wider picture.
What the work costs
These figures come from published trade cost guides, not our own pricing — Evova doesn’t install chargers or set prices for jobs.
| Option | Typical cost (research) | When it applies |
|---|---|---|
| Spare way in your existing unit | Usually priced within the standard install | Modern board with space and suitable RCD protection |
| Small separate unit for the charger | Around £30–£40 for the unit itself (MyJobQuote, 2026), plus labour and certification | Board full or unsuitable, but otherwise safe |
| Full consumer unit replacement | £350–£750, average around £525 (MyJobQuote, 2026); Checkatrade puts a typical job at around £485 | Old, unsafe or rewireable board |
Last checked July 2026. For context, loveelectric (2026) puts a typical fully installed home charger at £800–£1,200, with a board replacement adding £500–£900 where needed. See our full installation cost guide.
Two things to budget for beyond the headline figure. A full board swap typically takes 4–8 hours, so it turns a normal single-visit 2–4 hour charger install into a longer day. And consumer unit replacement is notifiable work under Part P of the Building Regulations — if your electrician isn’t registered with a competent person scheme, Building Control approval adds roughly £120–£200 (MyJobQuote, 2026). Any competent installer handles the notification; it’s a fair thing to check when comparing quotes from installers near you.
One grant note: if you qualify for the EV chargepoint grant — in 2026 that’s mainly renters and flat owners, not homeowners in houses — it covers 75% of the combined supply and install cost up to £500 per socket (last checked July 2026; see GOV.UK). Substantial board work can push a job well past that cap, so treat it as a discount rather than full cover. Who qualifies is on our grants hub.
Your main fuse: 60A, 80A or 100A
Separate from the consumer unit is the main fuse — the sealed cut-out where the supply enters your home. Most homes have a 60A, 80A or 100A fuse — some older properties smaller — and your installer will check the rating rather than guess.
Under the Energy Networks Association rules, if your home’s maximum demand including the charger is 60A or less, the installer can fit the charger first and notify your distribution network operator (DNO) within 28 days — no advance permission needed. Only where demand would exceed 60A, or the cut-out’s rating, must the DNO approve first. Your installer handles the paperwork; there’s more detail in our DNO notification guide.
If a fuse upgrade is genuinely needed, it’s often painless. UK Power Networks upgrades 30A or 60A fuses to 80A or 100A with a free site visit, targeted within 15 working days (last checked July 2026); other DNOs’ policies vary — often free, but your DNO will confirm. The main complication is a looped supply shared with a neighbour, which has to be re-planned and can add cost and time. And sometimes no upgrade is needed at all: smart chargers can use a CT clamp to throttle charging when the rest of the house is busy, keeping you under the fuse rating.
Surge protection and earth rods
Two regulation points often surface in quotes. Surge protection: under the current wiring regulations, a surge protection device (SPD) should be fitted with a new consumer unit unless the owner declines the protection and accepts the risk — installers are advised to get any refusal in writing. A Type 2 SPD is sufficient for most homes and a modest line on the quote. Earth rods: older EV installs often needed an earth electrode because a PME supply can’t be the sole means of earthing an outdoor charging point, but most modern chargers now build in open-PEN fault protection, satisfying the rule without a rod.
Wiring regulations, DNO processes and typical prices all move over time — the figures here were last checked in July 2026, and GOV.UK is the official source for grant rules. For everything else, a good installer will assess your board and supply as part of a standard quote — find an installer near you, or start with our home charging hub.