18 Edition Wiring Regulations Summary


Since January 2019, after an initial grace period, electrical contractors (gas engineers and kitchen fitters also) have been obliged to observe the 18th Edition wiring regulations.

The main changes when the 17th Edition gave way to the 18th Edition are:

  • Lightning risk assessment for protection against overvoltages using SPD surge protection devices - If a risk assessment has not taken place then overvoltage protection must be used.
  • Recommendation to use AFDD (Arc Fault Detection Devices) against the risk of fire in a fixed installation.
  • Guidance on design and installation of systems for storing and producing energy locally.
  • Embedded heating systems for sports fields and lawns.
  • Electrical vehicle charging requirements.
  • Interlocked sockets requirement for campsite hookups.

18th Edition Amendment 1

This amendment focussed on EV electrical vehicle charging installations and acceptable alternatives to the use of earth electrodes.18th Edition Amendment 2 (March 2022)

18th Edition Amendment 2 (March 2022)

  • 30mA RCD protection requirement for sockets in commercial and industrial installations.
  • Mandatory AFDD installation for circuits supplying socket outlets (except in circumstances where disconnection could cause danger).
  • Earth electrode or equivalent system required for new premises with foundations.

The Institution of Engineering and Technology

Information and help for electrical installers