Wiring Regulations BS7671

18th edition, published in July 2018 and applicable to electrical installations designed from 1 January 2019.

This video is a summary of the main changes compared with the previous edition (BS7671:2008, 3rd Amendment 2015). Future videos in this series will cover the individual changes in more detail.

Printed book available from Amazon. Note that many older editions are still available, these have different coloured covers. Make sure you are buying the correct version - BS7671:2018, blue cover.

BS7671:2018 18th Edition

View this video on Youtube.

Summary of changes in the 18th edition of BS7671 Wiring Regulations

All changes compared to the previous edition are indicated by a vertical line in the right margin. However note that many of these changes are only minor, including things like punctuation changes, definitions such as a.c. changing to AC, renumbering of some regulations, references to other standards with updated numbers and others where only a single word has been amended.

Part 1

Scope of the regulations now includes shore connections for inland navigation vessels. Moving walkways and escalators are specifically excluded.
Where equipment is used outside the scope of it's standard, this must be recorded on the electrical certificate as specified in Part 6.

Part 2

Around 20 new definitions with a small number of amendments.
Discrimination is now Selectivity.

Part 3

Substantially identical. Only a few very minor changes here, most of which are a result of changes elsewhere.

Part 4

Part 4 contains a number of significant changes and additions. Some of the more substantial changes include:

Part 5

Part 6

Part 7

Most of Part 7 contains minor amendments. More substantial changes include Section 722 Electric Vehicle Charging and Section 753 Heating Cables.
A new Section 730 covers onshore units of electrical shore connections for inland navigation vessels.


Many minor changes here, including updated references to many other standards.
Appendix 6 (model forms for certification and reporting) has a number of changes, including extra columns on the model schedule of test results for insulation resistance test voltage and AFDD test button operation.
Appendix 14 (earth fault loop impedance) has been relocated into Appendix 3. Appendix 14 now covers prospective fault current.
A new Appendix 17 covers energy efficiency when designing and erecting electrical installations.