Wiring Regulations - BS 7671

This technical guidance concerning the application of the requirements of BS 7671 (as amended) Requirements for electrical installations has been discussed and agreed by a forum, the Wiring Regulations Advisory Group, comprising technical representatives from the following bodies, hosted by Electrical Safety First:

Please note that neither Electrical Safety First nor the forum is able to respond directly to technical questions from individuals. Electrical contractors and installers seeking technical advice on the application of the requirements of the 18th Edition (as amended) should contact their registration or trade body in the first instance. If the registration or trade body wishes to establish a consensus of opinion, they may refer the question to the forum for consideration. If the forum is able to agree on an appropriate answer, it will be added to the guidance.

The answers provided by the forum in this part of the website assume that the designer and installer intend to comply fully with the requirements of BS 7671: 2018 (as amended). All new and rewired installations designed after 31st December 2018 are, without exception, required to comply fully with the requirements of the amended standard. Where exceptionally, after that date, designers and/or installers decide to adopt alternative approaches for alterations and additions to existing installations, they must be recorded as departures from the current standard in the box provided for the purpose on electrical installation certificates based on the model form given in the BS 7671: 2018 (as amended). Where such an alternative approach is taken, the designer and/or installer (as appropriate) must be prepared to justify the decision, and the resulting degree of safety of the installation must not be less than that obtained by compliance with the amended standard.

This guidance is intended for use only by electrically competent persons.