Industry guidance on the Wiring Regulations

Guidance on the application of the requirements of the 17th Edition of the IET Wiring Regulations, as amended
(BS 7671: 2008 incorporating Amendment 1)

The technical guidance concerning the application of the requirements of BS 7671: 2008 given in this section of the website has been updated as necessary to take into account the publication of Amendment 1 in July 2011. The guidance has been discussed and agreed by a forum comprising technical representatives from the following bodies, hosted by the Electrical Safety Council:

The guidance is intended for use by electrically competent persons.

NEW OR REWIRED DOMESTIC AND SIMILAR INSTALLATIONS
ALTERATIONS AND ADDITIONS IN DOMESTIC AND SIMILAR PREMISES
PLACES OF WORK - NEW INSTALLATIONS
PERIODIC INSPECTION OF EXISTING DOMESTIC AND SIMILAR INSTALLATIONS

Please note that neither the Electrical Safety Council 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 17th 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 appropriate topic section indicated above.

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: 2008, incorporating Amendment 1. All new and rewired installations designed after 31 December 2011 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: 2008 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.