Hi Peter

British Standard 7671 (BS7671) is a set of electrical standards published by the Institute of Electrical Engineers in the UK. The standards are not a legal requirement but a set of standards which will ensure a safe and proper electrical installation. Some contracts specify that the electrical element of the installation will conform to BS7671 and so at this point they become legally binding on the installer.

http://www.iee.org/Publish/WireRegs/

The regulations cover all aspects, from fuse selection, wire sizing, earthing and bonding, special installations such as caravans, swimming pools, farming (cows are very suscepable to electrical shock from earthing grids) etc. and mostly all new or refurbishment work currently carried out in the UK complies with the regs. There is no defence in UK law if your electrical installation work kills someone - you will be charged with MURDER.

We also have a voluntary inspection council that anyone involved with electrical work can join http://www.niceic.org.uk/ and membership of this organisation gives credibility to your business as the customer knows you are working to set standards.

Argus is right about trying to explain the regs in a short sentence - it's just not possible