Most homeowners only think about their wiring when something goes wrong, yet electrics have a working life just like a boiler or a roof. If your house was last rewired more than 25 to 30 years ago, or you are planning an extension or major renovation, it is worth knowing what to look for. Here is how to judge whether a rewire is actually needed, and what it involves.
The quickest clue is the age of the installation, not the age of the house. A Victorian terrace rewired in 2010 is fine; a 1970s semi with its original cabling may not be. Rubber-insulated cable (common before the 1960s) and early PVC wiring from the 1960s and 70s degrade over time, and the insulation can crack and expose live conductors.
You can spot older installations without touching anything. Look at the consumer unit: an old fuse box with rewirable fuses or a wooden backboard suggests the wiring predates modern standards. Other giveaways are round-pin sockets, black rubber or fabric-covered cables, sockets mounted on skirting boards, and light switches in bathrooms rather than pull cords.
Some symptoms point to wiring that is failing now rather than simply old. Frequent tripping, fuses that blow repeatedly, flickering or dimming lights when appliances switch on, and a faint fishy or burning smell near sockets all warrant investigation. Scorch marks or discolouration around sockets and switches, or sockets that feel warm, mean you should stop using them and get an electrician in promptly.
A mild tingling sensation when you touch an appliance or switch is a sign of an earthing fault and should be treated as urgent. None of these automatically means a full rewire, but they do mean the installation needs testing rather than guesswork.
The sensible first step is an Electrical Installation Condition Report (EICR), carried out by a qualified electrician. It tests the whole installation and grades any defects: C1 (danger present), C2 (potentially dangerous) and C3 (improvement recommended). Only C1 and C2 findings make the installation unsatisfactory. In London an EICR for a typical three-bedroom house usually costs somewhere between 150 and 300 pounds depending on the size of the property and number of circuits.
An EICR often shows that a partial upgrade is enough: a new consumer unit, extra circuits or replacing a damaged section. A full rewire tends to be justified when the cable insulation itself has degraded throughout, when there is no earth on the lighting circuits, or when the installation simply cannot support modern demands such as electric showers, kitchen appliances and car charging.
If you are extending or renovating, that is by far the best moment to rewire. The messy part of a rewire is chasing cables into walls and lifting floors, so doing it while walls are already open can save a significant share of the cost and avoids redecorating twice. It also lets you plan sockets, lighting circuits and future additions like an EV charger properly rather than bolting them on later.
As a rough guide, a full rewire of a three-bedroom London house typically falls between 4,500 and 9,000 pounds, taking around 5 to 10 days, though it depends on the size of the property, access, and the finish required afterwards. Older solid-wall properties, common across London, often cost more because chasing brick and making good takes longer than working in modern stud walls. Any new circuits must be certified under Part P of the Building Regulations, so always use an electrician registered with a scheme such as NICEIC or NAPIT.
No. Age is a prompt to get the installation tested, not a rule. An EICR will tell you whether the wiring is still safe, needs partial upgrades or genuinely needs replacing.
You can, but expect disruption: floorboards up, power off in sections and dust throughout. Many people rewire room by room or time it to coincide with a renovation, which is usually cheaper and far less disruptive.
There is no legal requirement to rewire before selling, though buyers' surveys often flag old electrics. Landlords in England must have a valid EICR at least every five years and fix any C1 or C2 defects, which sometimes does lead to rewiring work.