British StandardBS 7671 "Requirements for Electrical Installations. IET Wiring Regulations.", informally called The "Regs" (wiring regulations), is the national standard in the United Kingdom for electrical installation and the safety of electrical wiring in domestic, commercial, industrial, and other buildings. In general, BS 7671 applies to circuits supplied at nominal voltages up to and including 1000 volts AC or 1500 volts DC. The standard therefore covers the 230 volt 50 Hz AC mains supply used in the UK for houses, offices, and commerce.
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. It did not become a recognized British Standard until the publication of the 16th edition in 1992.
The standard is maintained by the Joint IET/BSI Technical Committee JPEL/64, the UK National Committee for Wiring Regulations, and published by the IET (formerly IEE). 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) publish numerous titles concerning acceptable standards of design/safety/quality across different fields.
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 and 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.
The 17th edition, released in January 2008 and amended in 2011 ("Amendment 1"), 2013 ("Amendment 2") and January 2015 ("Amendment 3") is the latest edition of BS 7671, and became effective for all installations designed after 1 July 2008. One of the more significant changes is (chapter 41) that 30 mA RCDs will be required for socket outlets that are for use by ordinary persons and are intended for general use. This improves the level of protection against electrical shock in the UK to a level comparable to that in other EU countries. The 17th edition and its amendments incorporated new sections relating to microgeneration and solar photovoltaic systems, non-combustible consumer units, RCDs, and breakers (including high resilience breaker layout).
As originally published highlights - RCDs required for most outlets
Amendment 1 highlights - high resilience consumer units
Amendment 2 highlights - electric vehicle charging added, earlier change incorporated for medical locations
Amendment 3 highlights - non combustible consumer units/enclosures
Part P of the Building Regulations ("Requirements for Electrical Installations") comes into force, covering legal requirements for UK electrical installations. The guidance in the Approved Documents refers to BS 7671 as being one way to achieve compliance. The version in force when the law came into effect was the 16th edition, BS 7671:2001, as amended in 2002 and 2004.
Amended 2015 ("Amendment no. 3") - current standard as of April 2015