BS 7671

Formal recognition as a British Standard did not occur 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 edition is BS 7671:2018+A4:2026, which is the 18th Edition, originally published in 2018, further incorporating amendment number 4, issued in 2026.

Scope

Locations

The regulations in BS 7671 apply to the design, selection, erection and verification of electrical installations such as those of:

1. residential premises
2. commercial premises
3. public premises
4. industrial premises
5. prefabricated buildings
6. low voltage generating sets
7. highway equipment and street furniture
8. locations containing a bath or shower
9. swimming pools and other basins
10. rooms and cabins containing sauna heaters
11. construction and demolition sites
12. agricultural and horticultural premises
13. conducting locations with restricted movement
14. caravan / camping parks and similar locations
15. marinas and similar locations
16. medical locations
17. exhibitions, shows and stands
18. solar photovoltaic (PV) power supply systems
19. outdoor lighting
20. extra-low voltage lighting
21. power over ethernet
22. mobile or transportable units
23. caravans and motor caravans
24. electric vehicle charging
25. operating and maintenance gangways
26. temporary installations for structures, amusement devices and booths at fairgrounds, amusement parks and circuses including professional stage and broadcast applications
27. floor and ceiling heating systems
28. onshore units of electrical shore connections for inland navigation vessels.

'Premises' covers the land and all facilities including buildings belonging to it.

Exclusions:

1. systems for the distribution of electricity to the public other than prosumer's installations covered by Chapter 82
2. railway traction equipment, rolling stock and signalling equipment
3. equipment of motor vehicles, except those to which the requirements of the Regulations concerning caravans or mobile units are applicable
4. equipment on board ships covered by BS 8450, BS EN 60092-507, BS EN ISO 13297 or BS EN ISO 10133
5. equipment of mobile and fixed offshore installations
6. equipment of aircraft
7. those aspects of mines specifically covered by Statutory Regulations
8. radio interference suppression equipment, except so far as it affects safety of the electrical installation
9. lightning protection systems for buildings and structures covered by BS EN 62305
10. those aspects of lift installations covered by relevant parts of BS 5655 and BS EN 81 and those aspects of escalator or moving walk installations covered by relevant parts of BS 5656 and BS EN 115
11. electrical equipment of machines covered by BS EN 60204
12. electric fences covered by BS EN 60335-2-76
13. the DC side of cathodic protection systems complying with the relevant part(s) of BS EN ISO 12696, BS EN 12954, BS EN ISO 13174, BS EN 13636 and BS EN 14505.

Supply characteristics

BS 7671 only covers electrical systems with the following characteristics:

• having a nominal voltage up to but not exceeding 1000V AC or 1500V DC
• for AC having a supply frequency of 50, 60 or 400Hz, though the use of other frequencies for special purposes is not excluded.

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.