Many London homes — particularly Victorian and Edwardian terraces built before 1940 — have electrical wiring that is reaching the end of its useful life or has already well exceeded it. Knowing the signs can prevent a serious electrical incident.
Signs you may need a rewire
Rubber-insulated wiring
Properties built before around 1970 may have rubber-insulated wiring (also called VIR — vulcanised india rubber). Rubber insulation deteriorates over time, becoming brittle and cracking. Old rubber wiring is identifiable by its distinctive cloth-braided outer sheath, typically in black or brown. If you see this type of wiring in your property, it should be replaced as a priority.
Aluminium wiring
During the 1960s and 1970s, aluminium wiring was sometimes used as a cheaper alternative to copper. Aluminium wiring presents a significant fire risk as the connections oxidise and loosen over time. It is identifiable by its silver-grey colour rather than the orange-red of copper. Aluminium wiring requires specialist treatment and should be addressed urgently.
Fuse box rather than consumer unit
If your property still has an old fuse box (with rewirable or cartridge fuses rather than modern MCBs and RCDs), this is a strong indicator that the installation has not been updated in decades. A modern consumer unit provides significantly better protection and is a requirement under current Building Regulations for new installations.
Frequent tripping of circuits
If circuit breakers trip frequently without apparent cause — particularly if this happens across multiple circuits — this can indicate deteriorating insulation or connections that are causing excessive earth leakage. This should be investigated promptly.
Burning smells from sockets or switches
A burning or hot plastic smell from an electrical fitting is an immediate warning sign. This indicates a poor connection or overloaded circuit that could lead to a fire. Switch off the affected circuit and call an electrician immediately.
Discoloured sockets and switches
Brown or black discolouration around a socket or switch face plate indicates that it has overheated. Even if there is no current smell, this should be investigated and the fitting replaced.
Sockets without earthing
Two-pin (non-earthed) sockets are a clear sign of very old wiring that predates the UK's adoption of three-wire earthed circuits. These should be replaced as part of a full rewire.
What does a full rewire involve?
A full house rewire replaces all the electrical wiring, the consumer unit, and all sockets, switches and light fittings in the property. It is a disruptive but straightforward job that typically takes 2–5 days depending on property size.
Our engineers chase cables into walls and sometimes lift floorboards to run new cable through the floor. All chasing is made good and left ready for a decorator. At the end of the job, you receive a Part P Building Regulations certificate confirming the new installation is compliant.
Rewire costs in London
| Property size | Typical cost |
|---|---|
| 2 bedroom flat / house | £2,000–£2,500 |
| 3 bedroom house | £2,500–£3,500 |
| 4 bedroom house | £3,200–£4,500 |
| 5+ bedroom house | £4,500–£6,500+ |
Not sure if you need a rewire? An EICR will identify whether your electrical installation needs partial or full replacement. Book an EICR from £99 →