British Standard BS 7671 "Requirements for Electrical Installations. IET Wiring Regulations", informally called in the UK electrical community "The Regs", is the national standard in the United Kingdom for electrical installation and the safety of electrical wiring systems. It did not become a recognized British Standard until after the publication of the 16th edition in 1992. The standard takes account of the technical substance of agreements reached in CENELEC. BS 7671 is also used as a national standard by Mauritius, St Lucia, Saint Vincent and the Grenadines, Sierra Leone, Singapore, Sri Lanka, Trinidad and Tobago, Uganda, Cyprus, and several other countries, which base their wiring regulations on it. The latest version is BS 7671:2018+A3:2024 (18th Edition, amendment 3) issued in 2024.

Scope

Locations

The regulations in BS7671 apply to the design, selection, erection and verification of electrical installations within: Exclusions:

Voltages

BS 7671 only covers electrical systems with the following characteristics: This includes low-voltage installations, as found in most domestic and commercial properties, and extra-low-voltage systems, but excludes high voltage, as found in generation, transmission and distribution networks.

Compilation and publication

The standard is maintained by the Joint IET/BSI Technical Committee JPEL/64, the UK National Committee for Wiring Regulations, and published jointly by the IET (formerly IEE) and BSI. Although the IET and BSI are non-governmental organisations and the Wiring Regulations are non-statutory, they are referenced in several UK statutory instruments, and in most cases, for practical purposes, have legal force as the appropriate method of electric wiring. The BSI (British Standards Institute) publishes numerous titles concerning acceptable standards of design/safety/quality across different fields.

History of BS 7671 and predecessor standards

The first edition was published in 1882 as the "Rules and Regulations for the Prevention of Fire Risks arising from Electric Lighting." The title became "General Rules recommended for Wiring for the Supply of Electrical Energy" with the third edition in 1897, "Wiring Rules" with the fifth edition of 1907, and settled at "Regulations for the Electrical Equipment of Buildings" with the eighth edition in 1924. Since the 15th edition (1981), these regulations have closely followed the corresponding international standard IEC 60364. In 1992, the IEE Wiring Regulations became British Standard BS 7671 so that the legal enforcement of their requirements was easier both with regard to the Electricity at Work regulations and from an international point of view. They are now treated similar to other British Standards. BS 7671 has converged towards (and is largely based on) the European Committee for Electrotechnical Standardization (CENELEC) harmonisation documents, and therefore is technically very similar to the current wiring regulations of other European countries.

Timeline

The historical timeline of publication can be found within documents published by the IET, such as within the PDF detailing amendment 3 to the 18th edition, and is summarised below, along with some notable other events. Only major changes between editions/amendments are noted.