How much does it cost to rewire a house, and do I actually need one?

Rewiring is disruptive, expensive and often unnecessary. The single most useful thing you can do before deciding is to get an EICR, because the insulation resistance results tell you whether the cable is actually failing or whether the installation simply has an old board and some accumulated poor alterations.

Step by step

1. Establish the age and type of the cable, not the board.PVC twin-and-earth in red and black, from roughly the 1960s onward, commonly tests well and has decades left. Rubber insulated cable, typically pre-1960s, perishes and cracks. Cloth-covered or lead-sheathed cable is older again and is at end of life. That distinction decides the whole question.
2. Get an EICR before getting rewire quotes.The insulation resistance figures on the schedule of test results are the evidence. Circuits testing above the required value are healthy. Multiple circuits testing low is the case for a rewire. Without that data, a rewire quote is a guess.
3. Know the genuine indicators.Rubber or fabric insulation. Lead-sheathed cable. No earth conductor on lighting circuits throughout. Round-pin sockets still in use. Multiple circuits failing insulation resistance. Widespread deterioration rather than one bad circuit.
4. Know the false indicators.An old fuse box on its own — that is a board change. Red and black cable in good condition. One faulty circuit. Not enough sockets. All of these have cheaper answers than a rewire.
5. Understand what a full rewire involves.Every circuit replaced from the consumer unit outward. Floorboards up, walls chased, ceilings drilled, a new consumer unit, new accessories throughout, then full testing and certification. Then plastering, decorating and floor coverings. Typically one to two weeks of electrical work in an empty house, longer if occupied.
6. Consider a partial rewire.Where testing shows some circuits sound and others not, replacing only the failing circuits is legitimate and much cheaper. It is a common and sensible outcome and a good electrician will suggest it where the evidence supports it.
7. Budget in two parts.Electrical work for a typical three-bedroom house is broadly £3,500 to £7,000, with London and larger or awkward properties higher. Making good — plastering, decorating, floor coverings — is a separate cost and is often underestimated; allow meaningfully for it.
8. Sequence it with other work.A rewire is dramatically cheaper in an empty house, before floors are laid, and alongside replastering. Doing it during a kitchen or bathroom refit, or between tenancies or before moving in, saves a great deal of the making-good cost.
9. Specify what you want while it is open.Socket positions and quantities, outside sockets, a garden or shed supply, network cabling, positions for wall lights, an EV chargepoint circuit. All of these are cheap while the walls are open and expensive afterwards. Walk the house room by room before work starts.
10. Get the certification.A full or partial rewire produces an Electrical Installation Certificate with a full schedule of test results, plus building control notification. Keep it permanently.

Tips

• Get three quotes and compare what is included — making good and decoration are the items that vary most between them.
• Ask what happens to the existing cables. Removing dead cable is tidier and avoids confusion at future work; leaving it buried is cheaper.
• If you are on a tight budget, a consumer unit replacement plus targeted remedials often delivers most of the safety benefit at a fraction of the cost. Ask the electrician to price that option too.

Common mistakes

• Rewiring because the fuse box is old — A board replacement addresses the protection. The cable's condition is a separate question and is answered by testing, not by the age of the board.
• Rewiring an occupied house to save moving out — It costs more, takes far longer, and the living-with-it cost is high. If there is any way to do it empty, do it empty.
• Not deciding socket positions before work starts — Adding a socket after the plastering is done costs many times what it costs while the walls are open.

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