The latest update to the IET Wiring Regulations reflects many of these changes.
BS 7671:2018+A4:2026, commonly known as Amendment 4, was published on 15th April 2026 and introduced significant updates to the requirements governing electrical installations across the UK.
For organisations responsible for complex buildings and estates, understanding these changes is important when planning new installations, upgrades, alterations and ongoing electrical maintenance.
BS 7671, the IET Wiring Regulations, is the UK national standard for electrical installations and provides requirements covering their design, installation, inspection, testing and verification.
The standard applies across domestic, commercial and industrial environments and is fundamental to maintaining safe electrical installations.
Amendment 4 is a significant update to the 18th Edition, reflecting the continued development of electrical technology and the changing ways power is generated, distributed and used within modern buildings.
There are changes throughout BS 7671, but several areas are particularly relevant to organisations managing complex electrical infrastructure.
A new chapter has been introduced covering stationary secondary batteries used for electrical storage and the supply of electrical installations.
Battery storage is becoming increasingly common as organisations invest in renewable energy, energy resilience and more sophisticated power management systems.
Amendment 4 introduces requirements covering areas including system design, battery location, ventilation, power conversion equipment and protective devices.
For estates teams considering battery storage, these requirements need to be considered from the earliest stages of electrical design rather than once equipment has already been selected or installed.
One of the most significant areas of change is Section 710, covering medical locations.
Electrical resilience within healthcare environments is critical. Hospitals and other clinical settings contain areas where interruption to electrical supplies can have serious consequences for patient care.
Amendment 4 significantly revises the requirements for these environments, including requirements relating to medical IT systems, supplementary protective equipotential bonding and continuity of electrical supplies.
For healthcare estates teams, the changes reinforce the importance of considering electrical infrastructure as an interconnected system. Distribution, standby power, UPS and IPS systems, testing and ongoing maintenance all contribute to ensuring critical areas have the resilient electrical supply they require.
Power over Ethernet, or PoE, now has a dedicated section within BS 7671.
PoE allows network cabling to carry both data and electrical power, reducing the need for separate power supplies for certain equipment.
Its use has grown considerably across modern buildings and can support equipment including lighting, sensors, access control devices and other connected technology.
As buildings become increasingly digitally connected, the introduction of dedicated requirements provides greater clarity around the safe design and installation of these systems.
Amendment 4 also introduces requirements covering functional earthing and functional equipotential bonding for information and communication technology equipment and systems.
This is increasingly relevant as electrical and digital infrastructure become more closely integrated.
From communications networks and building management systems to connected security and monitoring technology, modern estates depend on reliable ICT infrastructure. Electrical design therefore needs to consider both the safety and operational requirements of these increasingly connected systems.
The publication of Amendment 4 does not mean every existing electrical installation suddenly requires replacement. However, organisations planning new electrical works, refurbishment programmes or significant alterations should understand how the updated requirements may affect their projects. It is also an opportunity to consider the wider condition and suitability of electrical infrastructure.
Older buildings may have electrical systems that have evolved considerably over time, with new equipment and technology added as operational requirements have changed. In healthcare and other complex environments in particular, understanding the capacity, condition and resilience of the existing infrastructure is essential before further alterations are made.
Reviewing planned projects, electrical specifications and existing asset information now can help organisations identify where Amendment 4 needs to be considered.
Amendment 4 was published on 15 April 2026 and can already be used for electrical works.
A six-month transition period means the previous version, BS 7671:2018+A2:2022+A3:2024, remains valid until 15 October 2026. After this point, Amendment 4 becomes the applicable version of the standard.
For estates teams, electrical contractors and those responsible for upcoming capital programmes, the transition period provides an opportunity to review specifications, planned works and internal requirements before the previous edition is withdrawn.
With more than 50 years of electrical engineering experience, RD Jukes supports organisations with the design, installation, testing, maintenance and upgrade of electrical infrastructure.
Our experience includes working within healthcare, public sector, commercial and other complex operational environments where electrical safety, resilience and continuity of service are essential.
From mains infrastructure and power distribution through to standby power, UPS and IPS systems, electrical testing, emergency lighting and specialist healthcare systems, our teams understand the challenges involved in delivering electrical works within live and sensitive environments.
As electrical standards and technologies continue to develop, having the right technical expertise can help ensure electrical infrastructure remains safe, reliable and fit for the demands placed upon it.
Planning electrical upgrades or reviewing your existing infrastructure? Speak to RD Jukes about your requirements.