What does an RCD do?
A residual current device cuts power within milliseconds if it detects current leaking to earth — the main protection against electric shock from a faulty appliance or damaged cable. Modern consumer units have RCD protection built in across multiple circuits (RCBOs); older ones may only protect part of the property.
Red flags in a cheap electrical quote
A quote significantly below the others is worth asking about before accepting — check it includes a proper consumer unit (not a budget one that doesn't meet current standards), covers making good afterwards, and includes the certificate you're entitled to for notifiable work. Cash-only, no fixed address, and no registration number are all worth asking about directly.
How long does electrical work take?
A socket or switch swap is usually under an hour. A consumer unit replacement is typically a full day, often with the power off for several hours. A full rewire in an occupied property commonly takes 5 to 10 days depending on size and access, plus time afterwards for plastering and redecorating that isn't part of the electrical work itself.
Do I need an electrical certificate to sell my house?
There's no legal requirement to provide one, but conveyancing solicitors routinely ask whether any electrical work done during your ownership was certified, and a missing certificate for notifiable work (a rewire, a consumer unit change, a kitchen or bathroom circuit) can hold up or complicate a sale. Keep any Electrical Installation or Building Regulations certificates with your house paperwork.
Electrics in kitchens — circuits for appliances
A kitchen refit usually means new dedicated circuits for higher-draw appliances (oven, hob, dishwasher) rather than sharing a single ring main, plus RCD protection for anywhere near a sink. If you're changing the kitchen layout, plan socket and circuit positions before the units go in — moving them afterwards means lifting worktops or units again.
First fix and second fix, explained
On a rewire or new build, "first fix" is running cables through walls and floors before they're closed up; "second fix" is fitting sockets, switches and light fittings once decorating is done. Getting the timing right with other trades on site avoids cables being covered before they're tested.
What affects the cost
Cost depends on the scope of the job, how much of the property needs to be accessed, the age and condition of the existing wiring, and whether the consumer unit needs upgrading. A single socket replacement is quick and low-cost; a full rewire in an older property takes longer, partly because of the making-good work afterwards.
Single phase vs three phase supply
Most UK homes run on a single-phase electricity supply, which is enough for typical household use. Larger properties, workshops, or homes adding multiple EV chargers or heavy machinery sometimes need a three-phase supply instead — this is arranged with the network operator, not just your electrician, and can take weeks.