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Useful Information

BS 7671

What is BS 7671

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.

Building regulations

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.

Approved Document P (Electrical safety)

Currently different part P documents apply to England and Wales . To see the full document for each click on the country name you are interested in.

There are three important differences between the documents which are briefly described below.

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 requirements

The 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.

In England an installer who is not a member of a registered competent person scheme, e.g. a DIY'er, may use a registered third party to certify notifiable work as an alternative to using a building control body. This is not allowed in Wales.

Notifiable electrical installation work

In 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.

In Wales notifiable work also includes work in a kitchen or involving electric floor or ceiling heating systems, outdoor lighting and power installations, solar photovoltaic power supply systems, small scale generators and extra-low voltage lighting installations other than pre-assembled CE marked lighting sets.

An installer who is not a member of a registered competent person scheme, e.g. a DIY'er , would typically do this via their local authority by completing and submitting a form and paying the appropriate fee.

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.

Testing and Inspecting electrical installations

Why have your electrical installation tested and inspected?

All electrical installations will deteriorate over time potentially becoming unsafe. In 2010, according to Electrical Safety First, 2.5 million people received an electric shock, 350,000 of who were seriously injured and 28 of who died. Click here for full details. Having your electrical inspection tested and inspected will highlight any defects to you.

How often should an electrical installation be tested and inspected?

How often an electrical installation should be inspected depends on the type of installation and its use. Advice from Electrical Safety First can be found here


What is an RCD?

An RCD, or residual current device, is a life-saving device which is designed to prevent you from getting a fatal electric shock if you touch something live, such as a bare wire. RCDs offer a extra level of personal protection to that provided by fuses and circuit-breakers.

An RCD is a sensitive safety device that switches off electricity automatically if there is a fault.

What do RCDs do?

RCDs are designed to protect against the risks of electrocution and fire caused by earth faults. For example, if you cut through the cable when mowing the lawn and accidentally touched the exposed live wires causing electric current to flow through your body to earth.

How do RCDs work?

RCDs constantly monitor the electric current flowing through the circuit(s) it is used to protect. If it detects electricity flowing down an unintended path, such as through a person who has touched a live part, the RCD will switch the circuit off very quickly, greatly reducing the risk of death or serious injury.

Types of RCDs

There are various types of RCDs that can be used to make sure you are always as safe as possible.

Fixed RCDs

These are installed in or next to the consumer unit (fusebox) and can provide protection to individual or groups of circuits. A fixed RCD provides the highest level of protection as it protects all the wiring and the sockets on a circuit, and any connected appliances.

Socket-Outlet RCDs

These are special socket-outlets with an RCD built into them which can be used in place of a standard socket-outlet. This type of RCD provides protection only to the people using equipment plugged into the special socket-outlet.

Portable RCDs

These plug into any standard socket-outlet. An appliance can then be plugged into the RCD. They are useful when neither fixed nor socket-outlet RCDs are available but, as with socket-outlet RCDs, they provide protection only to the people using equipment plugged into the portable RCD.

Do I already have a RCD?

To check if you have fixed RCD protection go to your consumer unit and have a look to see if there is a device with a pushbutton marked 'T' or 'Test'. This test button is part of an RCD.