Does your house need rewiring? Signs to look for

Age is a clue, not a verdict

Electrical Safety First is clear that there are no set guidelines for when a property should be rewired, and that old wiring is not unsafe just because it is old. A 1980s installation that has been looked after may be fine; a 1990s one that has been extended by amateurs may not. Condition decides it, and an EICR is how you find out.

Warning signs you can see or hear

• Heat marks or discolouring on plugs, sockets or switches
• Buzzing or crackling from sockets, switches or the board
• Fuses that blow or breakers that trip regularly
• A fuse box with rewireable fuses
• Round-pin sockets, or sockets mounted on skirting boards
• Lights that flicker when appliances switch on

Electrical Safety First advises getting a registered electrician to check the wiring promptly if you notice the first three.

Old cable types

Rubber-insulated cable, black or dull red and sometimes in a braided cover, was in general use until the early 1950s, according to the IET. It is now usually hardened and brittle, and some cable of this type may contain asbestos. Some PVC cable made between 1968 and 1975 has also been found to degrade, leaving green residue at the terminals. Neither can be made good; they need replacing.

Metro-land homes

Harrow was called the capital of Metro-land, the suburbs the Metropolitan Railway promoted from 1915, and much of Harrow, Wembley and Stanmore was built between the wars. Those houses were wired with rubber cable when new. Most have been rewired since, but the IET notes that concealed wiring often survives several upgrades while sockets and switches are changed, so a modern socket is no proof of modern cable.

What an EICR tells you

The insulation resistance test on each circuit shows how well the cable is holding the current in. Low readings across many circuits point to cable at the end of its life. The observations show whether problems are scattered, which repairs can fix, or everywhere, which points to a rewire. A home EICR is the right first step before anyone quotes for a rewire.