BS 7671 Amendment 4 (2026): What the New Wiring Regulations Mean for Your Commercial Premises

The UK’s wiring standard has changed. On 15 April 2026, the Institution of Engineering and Technology and BSI published Amendment 4 to BS 7671:2018 – the latest update to the 18th Edition IET Wiring Regulations, now widely known as the “Orange Book.” It can be used straight away, and from 15 October 2026 every new electrical installation must be designed and installed to it, when the previous “Brown Book” is formally withdrawn.

If you own, manage or maintain a commercial or industrial building in Aberdeen, Aberdeenshire or the wider North-east, that six-month window matters. Here’s what’s changing and why it’s already on our radar.

We’ve done the homework so you don’t have to

Our team recently attended SELECT’s annual toolbox talk on Amendment 4 at Pittodrie, hosted by Neil Sim and the SELECT team, and we’ve collected our copies of the new standard, ready for an internal roll-out across the business. Staying current with the regulations isn’t optional for us – it’s the baseline. It means that when you ask Aberdeen Electrical Services to design or carry out work, it’s already built to the standard you’ll be held to.

The changes most likely to affect your premises

Amendment 4 reflects how buildings have actually changed since the last update – more electronics, more charging, more data. A few of the changes have direct, practical consequences for commercial and industrial sites:

• Arc Fault Detection Devices (AFDDs) now reach beyond homes. The requirement has been extended to certain commercial premises with combustible contents; think stockrooms, archives, and workshop areas holding timber, paper or packaging and to outdoor or temporary installations fed from a permanent supply. If you store flammable stock, this is a fire-safety change worth a conversation.
• EV charge point requirements have been tightened and harmonised. As more workplaces and commercial sites add charging, the rules around load, diversity and fault detection have moved on. Getting the design right the first time avoids expensive rework.
• Surge (overvoltage) protection has been revised. Sensitive equipment – tills, servers, control systems, refrigeration is increasingly worth protecting against transient overvoltages, and the standard now reflects that.
• New requirements for ICT and Power over Ethernet (PoE) earthing and bonding. Modern offices and facilities run more of their building services over data cabling than ever, and Amendment 4 introduces specific provisions for it.
• A major revision of the requirements for medical locations. If you operate a clinic, dental practice or healthcare facility, the rules governing your installation have changed significantly.

Why this matters to you, not just your electrician

BS 7671 itself isn’t law but it is the recognised benchmark for meeting your obligations under the Electricity at Work Regulations and the Building Regulations. For a duty holder, “compliant with the current edition of BS 7671” is the line your insurer, your auditor and, if it ever came to it, a court would look for. New work that doesn’t meet Amendment 4 after October 2026 is a liability you don’t need to carry.

The good news: it’s straightforward to get ahead of. A periodic inspection (EICR), a review of any planned works, or simply briefing your facilities team can put you comfortably on the right side of the change well before the deadline.

How Aberdeen Electrical Services can help

Since 1998, we’ve been the North-east’s commercial and industrial electrical specialists, working across Aberdeen, Aberdeenshire, Moray and the surrounding area. We design, install, inspect, test and certify to the current standard, and our team is already getting up to speed on Amendment 4, so your projects are compliant by default.

Whether you need a compliance review ahead of October, an EICR on an existing installation, EV charge points specified correctly, or a commercial fit-out delivered to the new standard, we can help.

Get in touch to talk through what Amendment 4 means for your premises – email in**@***************co.uk or contact the team via our website.