Signs You Need a Rewire and What a Rewire Involves
The main signs you need a rewire are rubber, lead or fabric-covered cables, an old fuse box with rewireable fuses, no RCD protection, scorch marks or burning smells, and circuits that keep tripping. Wiring more than about 25 to 30 years old should be checked. An EICR confirms whether a full or partial rewire is needed.
Sam Ward Electrical, NAPIT registered (membership 63406). Last reviewed:
At a glance
- Key warning signs
- Old cable types, rewireable fuses, no RCDs, scorch marks, frequent tripping
- Get it checked
- Every 10 years in a home you own; every 5 years in a rental
- Best test
- An EICR
- Typical duration
- Around five to ten working days for a three-bedroom house
- Paperwork
- Electrical Installation Certificate and Building Regulations compliance certificate
What are the signs you need a rewire?
These ten signs you need a rewire are the ones electricians see most often in older homes:
- Old cable types: rubber, lead-sheathed or fabric-covered cables.
- An old fuse box with rewireable fuses instead of circuit breakers.
- No RCD protection on the consumer unit.
- Scorch marks, warm sockets or a burning smell around switches or sockets.
- Circuits that trip or fuses that blow frequently.
- Flickering or dimming lights that are not caused by the bulb.
- Sockets set in skirting boards, or old round-pin sockets.
- Too few sockets, with extension leads used throughout the house.
- Mild shocks or tingles from switches, sockets or appliances.
- No record of any inspection for more than 10 years, or wiring more than about 25 to 30 years old.
What do different cable types tell you?
The type of cable is one of the clearest clues to the age of your wiring.
| Cable | Era | What it usually means |
|---|---|---|
| Rubber-insulated | Before the 1960s | Insulation perishes with age; replacement needed |
| Lead-sheathed | Before the 1950s | Replacement needed |
| Fabric or cotton covered | Before the 1950s | Replacement needed |
| PVC with red and black cores | 1960s to 2004 | Often fine if tests are good |
| PVC with brown and blue cores | From 2004 | Current colours |
Red and black wiring is not a problem on its own: it was the standard until 2004, and many of these installations still test well.
Does old wiring always mean a full rewire?
No. Old wiring needs testing, not automatic replacement. An EICR shows whether the existing cables are safe, whether a partial rewire of one area is enough, or whether a full rewire is the sensible option. Often a new consumer unit and a few repairs are all that is needed.
What does a rewire involve?
A rewire replaces the cables, sockets, switches and light fittings, and usually the consumer unit. First fix runs new cables under floors and into walls before plastering; second fix fits the accessories once walls are made good. Everything is then tested, certified and registered under Part P.
How long does a rewire take?
A typical three-bedroom house takes around five to ten working days. Flats and smaller houses take less, while large houses or homes being renovated at the same time can take longer.
What affects the cost of a rewire?
The cost depends on the size of the property, the number of sockets, switches and lights, how easy it is to lift floors and reach ceilings, whether the consumer unit is replaced, and whether the house is empty or occupied. If you have spotted signs you need a rewire, an electrician can survey the property and give you a written quote that sets out each of these.
Sources and further reading
- Electrical Safety First
- Approved Document P: electrical safety in dwellings (GOV.UK)
- BS 7671 wiring regulations (IET)
