All domestic and commercial properties are required to meet the legal safety standards. They must meet British standards BS7671: 2008 and the new amendment 3 (IEE wiring regulations).
Where the electrical installation does not comply with the minimum safety requirements of BS7671: 2008 and the new amendment 3 (IEE wiring regulations) old wiring and accessories such as sockets, switches and light points must be changed to comply.
The best way to decide whether the state of a current installation complies to the British standards is to have a condition report carried out.