UK electrical wiring regulations

BS 7671 of the IET Wiring Regulations sets the standards which apply to the design, erection and  verification of electrical installations, as well as additions and alterations to existing installations, in the UK and many other countries.

It is important that property owners and commercial landlords have an adequate level of understanding and awareness of the changes to these electrical regulations in order to remain compliant.

• Protection against overvoltage: property owners/commercial landlords should consider installing surge protection devices on their installations to protect against transient overvoltages from lightning strikes or switching surges. The new regulations make clear that transient overvoltage protection must be provided where the overvoltage could result in serious injury or loss of life, interruption to public services or industrial and commercial activities, damage to cultural heritage, or a large number of individuals at the same location being affected.
• RCD protection: RCDs can no longer be excluded by risk assessment and are now required on lighting circuits (domestic), on all socket outlets with ratings up to and including 32A, and must be manually tested every six months.
• Arc fault detection devices: these are devices that automatically trip a circuit when they detect dangerous electric arcs. Installation of these devices are advised to mitigate the risk of fire.

• Euroclass cable ratings: all cables used in buildings must have a Euroclass rating. This is to prevent heat, smoke, flame spread, etc. Simply put, use the right class of cable type in the right location.
• Wiring support: all wiring systems must be supported (e.g. steel tray, trunking, etc.) to protect systems against premature collapse during fire. Previously, this only applied to escape routes.
• Embedded electric heating (e.g. surface heating in car parks, floors, ceilings and drainpipes): these systems must have protection against overheating and an earthed protective shield (e.g. metal mesh grid) in areas susceptible to damage.
  

The Health & Safety Executive (HSE) state they regard installations that conform to the standards set out in BS 7671:2018 as likely to achieve conformity with the relevant parts of the Electricity at Work Regulations 1989.

Part 6 of BS 7671 is fully dedicated to the routine inspection and testing of the installation by a 'Competent Person'.