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Guide: Changes to Wiring Regulations For Commercial Buildings

September 28th, 2022

Last updated: November 24th, 2023

IET’s wiring regulations are the national standard to which all wiring in commercial and domestic properties must conform. As a commercial landlord or business owner it is vital that you fully understand all of your responsibilities when it comes to building compliance and that includes the wiring regulations.

BS 7671 amendment 2 outlines the latest, up-to-date regulations. If you don’t adhere to electrical safety guidelines and laws for commercial properties and someone gets hurt, expect to face legal action under the two Occupiers’ Liability Acts. Even if the individual that is hurt is at the property because they are trespassing, you could face charges. It isn’t worth taking chances, and may commercial building owners and occupiers decide that a planned preventative maintenance schedule is a great way to keep your building compliant, and in good working order.

2022 Changes to Wiring Regulations

BS 7671:2018+A2:2022 Requirements for Electrical Installations is a new amendment that was first issued back in March 2022, and though many businesses have already made changes, the previous BS 7671:2018+A1:2020 was withdrawn on 27th September 2022. If your electrical systems and wiring are not up to date then it is now vital that you make changes or risk being in violation of the law.

BS 7671 is the wiring regulation that refers to “the design, erection, and verification of electrical installations, and to additions and alterations to existing installations.”

The British Standards Institution provide BS7671 along with all of the other BS documentation to provide a reference point and a simple guide to installations and electrics. This specifies the requirements and obligations for installations in industrial, commercial, and public locations as well as within residential buildings.

The documents must evolve over time as the changes to the way we live, and the way appliances are made change as well. For instance, the BS7671 document covers both solar photovoltaic (PV) power supply systems and electric vehicle (EV) charging.

If you are concerned about which documents are compulsory and statutory there is a handy guide here.

The Changes

Below is a brief overview of the changes and updates in the documentation. BS7671 changes are discussed below.

RCD Risk

In terms of RCDs and socket outlets, building owners may sometimes have been able to avoid using RCDs if they had done the right risk assessment, now an RCD must be in place whether or not there has been a risk assessment, if children or disabled people are present.

Earth Electrodes

Regulation 411.4.2 now recommends that an additional connection to earth using an electrode, is in place o PME earthing systems. This one is not a legal obligation, just a strong recommendation.

Protected Escape Route Addition

BS 7671 used to talk about escape routes in vague terms and people may not have fully understood. This amendment in regulation 442.1 defines an escape route as a route designed to be protected against fire for a specific period. This could include a route that uses fire dampers, and fire doors, for instance.

Arc Fault Detection

AFDDs (Arc Fault Detection Devices) are now required in circuits supplying socket-outlets with a rated current not exceeding 32 Amps in the following:

  • Higher risk residential buildings (HRRBs)
  • Homes in multiple occupation (HMOs)
  • Student accommodation
  • Care homes

This is not relevant to many commercial buildings and is aimed more at residential.

Protection Against Overvoltage

Regulation 443.4.1 refers to surge protection devices (SPDs) and has made it clearer when protection is required against overvoltage. They are now required where the overvoltage could cause the following:

  • Serious injury or loss of life
  • Failure of safety devices and services, for instance fire alarms
  • Financial loss or data loss

This is another of the regulations not 100% legally required, and the owner has to make a decision on what constitutes legal compliance.

Bonding of Outbuildings

Any building on a TN-S or TT earthing system can be bonded with an incoming cable protective conductor that relates to that specific building. In previous versions of the regulations the designer had to use the bonding from the main building.

Solar PV Systems

This is a section to check out, as there are nine new pages and a lot of new guidelines if you are using Solar PV systems.

Prosumer Electrical Installations

BS 7671 has also added another section related to prosumers, those who both produce and consume energy, which is becoming common with more businesses looking at ways to generate energy. Part 8 relates to this.

Electrical Installation Certification

If you need to complete electrical installation certificates you will be glad to know it has been condensed to a tick-box system, with 14 boxes to provide you with a reference to confirm if inspections have taken place (or whether they need to take place).


These changes are not to be ignored, especially now they are in full force. If you feel you would rather get the help of a maintenance service, Robinsons Facilities Services can help with maintenance and advice on all of your electrical installations.

Working across Yorkshire, we cover North YorkshireWest YorkshireEast Yorkshire and South Yorkshire and offer a fast, efficient response time to all breakdowns and repairs. Contact us today for all plannedreactive maintenance or emergency call out. Call 01423 226578 or get in touch to see how Robinsons Facilities Services can help.

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