The fourth amendment to BS 7671:2018, officially titled BS 7671:2018+A4:2026, signals a major step forward in electrical installation standards. As Rob Shepherd explains, it highlights just how rapidly the industry is evolving and adapting to new demands.
Coming into effect on 15 April 2026, BS 7671:2018+A4:2026 reflects the pace of technological change across the electrical industry, particularly when it comes to energy storage, digital infrastructure and specialist environments such as healthcare. For electrical contractors, the amendment is not just a technical update but a clear signal of where the industry is heading and what competencies will be expected moving forward.
So, what’s new?
One of the most important aspects of Amendment 4 is its recognition that modern installations are no longer limited to traditional circuits but increasingly incorporate renewable generation, battery storage, data infrastructure and smart controls. This means that electrical contractors must look at how different systems interact, while also considering how they are responsible for systems that consume and generate electricity.
A major addition within the amendment is the introduction of a dedicated framework for stationary secondary batteries, commonly referred to as energy storage systems. They are becoming increasingly common in both domestic and commercial settings, particularly when paired with solar PV installations. The amendment ensures that installations are equipped to handle bidirectional power flows and that risks such as overcurrent, fire hazards and system instability are properly mitigated.
For electrical contractors, this brings new responsibilities. Installing battery systems requires a clear understanding of protection requirements, fault conditions and the safe integration of storage with existing electrical infrastructure. Key safety considerations such as ventilation, thermal management, fault protection and isolation are addressed, ensuring contractors can design systems that are both efficient and safe.
Power rangers
Another significant development is the formal inclusion of power over Ethernet (PoE). This technology allows both power and data to be delivered over a single cable and is increasingly used in lighting systems, security installations and smart building applications. Its prevalence has blurred the lines between electrical and data installations, requiring contractors to expand their technical knowledge.
Contractors will need to consider factors such as cable bundling, current carrying capacity and the impact of higher power levels associated with modern PoE standards. Bundled cables can present overheating risks if not correctly specified and installed. As a result of this, electrical contractors may find themselves working more closely with IT professionals or taking on responsibilities that were previously outside their typical scope of work.
If you’d like to know more about the history of PoE and why it continues to be a game-changer, click this link: www.installeronline.co.uk/electric/power-over-ethernet-poe-what-installers-need-to-know/
A solid bond
As well as PoE, Amendment 4 also introduces guidance on functional earthing and bonding, particularly in relation to information and communication technology (ICT). As buildings become more digitally integrated, the reliability of ICT infrastructure is critical. This section recognises that traditional protective earthing alone is not always sufficient for sensitive electronic equipment and provides guidance on maintaining signal integrity and reducing electromagnetic interference (EMI).
Unlike protective earthing, which is primarily concerned with safety, functional earthing ensures the correct operation of sensitive electronic equipment. This distinction represents a significant shift in how earthing is approached within complex installations.
The growing reliance on electronic systems means that poor earthing practices can lead to issues such as data errors and equipment malfunction. Contractors working in commercial, industrial or technologically advanced environments will need to develop a deeper understanding of these principles to ensure installations perform as intended.
Health and safety
Healthcare environments present unique risks due to the presence of vulnerable patients and life support equipment. As such, Section 710 of BS 7671:2018, which deals with medical locations, has undergone extensive revision, reflecting advances in medical technology and changes in how healthcare facilities are designed and operated.
Electrical systems must now support a wider range of equipment while maintaining strict safety margins. Even small projects in medical environments will now demand a higher level of attention to detail and for contractors it means that inspection and testing procedures must be more thorough with comprehensive records. The need to document supplementary bonding resistance and other parameters increases accountability and ensures that installations meet the highest safety standards.
One step beyond
The focus on inspection, testing and documentation doesn’t just apply to healthcare environments though, as BS 7671:2018+A4:2026 introduces a broader emphasis on these practices across the board. Electrical contractors will be expected to provide clearer evidence that installations comply with the regulations, with more detailed verification processes in certain cases. This reflects a wider industry trend towards greater transparency and traceability.
As a result of this, contractors may need to adjust their workflows to allow for additional testing and record keeping. While this may initially be seen as an administrative burden, it also reinforces professional standards and can help protect contractors in the event of disputes or inspections. It is clear that accurate documentation is becoming an essential part of the job rather than an optional extra.
Opportunities and challenges
The evolving nature of electrical installations has implications for skills development. Contractors will need to expand their knowledge in areas such as energy storage, data systems and advanced earthing techniques, while a broader base of understanding will be necessary to keep pace with ongoing industry developments. Put simply, contractors need to ensure they can confidently design, install and verify systems that comply with the updated regulations.
From a business perspective, Amendment 4 presents both opportunities and challenges. On the one hand, the growth of technologies such as battery storage and smart systems creates new markets and revenue streams. On the other, gaining familiarity new technologies might increase the need for additional training, increased installation time and greater responsibility, all of which could place pressure on resources and margins.
Staying one step ahead
BS 7671:2018+A4:2026 addresses some of the most important industry developments. It also represents a clear indication of the direction of travel, while ensuring that the Wiring Regulations remain relevant in an increasingly complex and technology driven world. For electrical contractors, adapting to these changes will be key to maintaining compliance, ensuring safety and making the most of any new opportunities.
Contributors
Rob Shepherd (author)
Rob is Consulting Editor for InstallerELECTRIC. He is a well-respected journalist with a strong history in the electrical sector.
