BS 7671 is a British Standard detailing the requirements for electrical installations. It is not a statutory instrument, i.e. it is not the law.
The legal requirements that electrical installations must comply with are specified in statutory instruments such as the Building Regulations.
Why is it important to comply with BS 7671
Compliance with BS 7671 is accepted as evidence that the electrical installation meets the requirements of various statutory documents which together define the law with respect to electrical installations. Compliance with BS 7671 may be used in a court of law to demonstrate compliance with the law.
For example, Approved Document P says that electrical installations should comply with BS 7671 and complying with the Approved Documents is one way to show that you have complied with the building regulations which are the law.
Put another way, if a third party was injured by the electrical installation in your home, if you had a certificate showing that your electrical installation complies with BS 7671 you could use this certificate to show that your installation complied with the law and defend yourself from a claim by the third party.
In England and Wales there is a legal requirement for new builds and alterations and additions to existing properties to comply with the building regulations. This includes electrical work. A series of Approved Documents designated A to P give guidance on how to comply with the building regulations. Document P, often referred to as part p deals with electrical safety in dwellings.
Other Approved Documents relevant to electrical work are:
Approved Document A (Structural safety) e.g. an electrician may need to cut into walls and / or floor joists and must do so in a way so as not to compromise the structural safety of your home.
Approved Document B (Fire safety) e.g. an electrician may need to make a hole through a wall, for instance to run a cable from one room to another, and must do so in a way that will not compromise the wall's ability to resist the spread of fire.
Approved Document E (Resistance to sound) e.g. an electrician may need to make a hole in a ceiling, for instance to install a light, and must do so in a way so as not to compromise the ceiling's ability to resist the transmission of sound.
Approved Document M (Access and use of buildings) e.g. when installing accessories an electrician must do so in way that they are accessible to all users including disabled people.
Changes in the technical guidance
The English version now refers to BS 7671: 2008 incorporating the 2011 amendment where as the Welsh version still refers to an earlier version of BS 7671.
Changes in the legal requirementsThe English version has reduced the range of electrical installation work that must be notified to Building Control. Notably electrical installation work in a kitchen must be notified to Building Control in Wales but not in England.
Notifiable electrical installation workIn England electrical installation work comprising the installation of a new circuit, the replacement of a consumer unit (also known as a fusebox) or any addition or alteration to existing circuits in a room containing a bath or shower or a room containing a swimming pool or sauna heater is classed as notifiable work and must be notified to building control.
An installer who is a member of a registered competent person scheme can notify building control via the scheme operator.
By way of example a DIY'er using Monmouthshire County Council to notify their work will have to pay a fee of £360. A member of the NICEIC competent person scheme (e.g. Oak Tree Electrical) can make the same notification via the NICEIC for £3. This is obviously a very significant saving which can be, and in the case of Oak Tree Electrical is, passed on to the customer.
How often should an electrical installation be tested and inspected?