Category Archives: 18th Edition Regulations

The Important Changes Electricians Need to Know in 2026

Leave a Reply

The UK electrical industry is approaching another important milestone, with BS 7671:2018+A4:2026 — the latest version of the IET Wiring Regulations — moving towards becoming the sole edition that installers should be working to.

The past three months have seen further guidance published on Amendment 4, clarification around Electrical Installation Condition Reports (EICRs), and updated supporting publications. There have also been changes to wider building regulations that electricians involved with new-build and refurbishment work should be aware of.

The biggest issue for October 2026 is simple: the transition period for the previous version of BS 7671 is coming to an end.

Amendment 4:2026 moves towards mandatory use

BS 7671:2018+A4:2026, often referred to as the “Orange Book”, is now available and represents a substantial update to the 18th Edition Wiring Regulations.

The IET says the previous BS 7671:2018+A3:2024 edition remains valid during a transition period until 15 October 2026. Until that date, installers can work to either version. After the transition period, the previous edition will no longer be the current standard.

For electricians and electrical contractors, October is therefore an important deadline.

Anyone still relying on the “Brown Book” should be making sure they have access to BS 7671:2018+A4:2026 and understand the changes before the transition period expires.

New requirements for battery storage

One of the most significant additions in Amendment 4 is a new chapter covering stationary secondary batteries.

This reflects the rapid growth in domestic and commercial battery energy storage systems.

Battery storage is increasingly being installed alongside solar PV, electric vehicle charging equipment and other low-carbon technologies. The IET says the new requirements are intended to address electrical energy storage and the supply of electrical installations.

This is particularly important for installers because battery systems can introduce different considerations from conventional electrical installations, including protection, isolation, earthing, installation location and interaction with other sources of supply.

The changes demonstrate how BS 7671 is increasingly having to accommodate installations where electricity is not simply supplied from the grid.

Power over Ethernet gets its own section

Another notable addition is a new section covering Power over Ethernet, or PoE.

PoE allows electrical power and data to be delivered through network cabling and is becoming increasingly common in buildings.

Examples include:

* Wireless access points
* CCTV cameras
* VoIP telephones
* Network equipment
* Building automation equipment
* IoT devices

The inclusion of PoE within BS 7671 recognises the growing overlap between traditional electrical installations and communications infrastructure.

This is an area that is likely to become increasingly important as smart buildings and connected devices become more widespread.

Functional earthing and ICT equipment

Amendment 4 also introduces requirements concerning functional earthing and functional equipotential bonding for information and communications technology equipment and systems.

This is another example of BS 7671 evolving beyond conventional mains electrical wiring.

Modern buildings contain increasing amounts of electronic equipment, networking infrastructure and communications systems. Earthing and bonding arrangements can therefore have implications not only for electrical safety but also for the reliable operation of sensitive electronic equipment.

Major changes to medical locations

Section 710, covering medical locations, has undergone a major revision.

The update also introduces a schedule of test results for recording the resistance of supplementary protective equipotential bonding conductors.

Medical electrical installations have particularly demanding requirements because loss of electrical supply or inadequate protection can have serious consequences.

Installers and inspectors working in hospitals, medical centres, dental practices and other healthcare environments should therefore pay particular attention to the revised requirements.

Changes to EICR reporting

One of the more immediately relevant changes for inspectors is the treatment of the FI — “Further Investigation” — classification on EICRs.

Under Amendment 4, C3 and FI classifications have been separated from C1 and C2 classifications.

Importantly, an FI classification no longer automatically makes an EICR unsatisfactory. The wording has also changed from further investigation being required “without delay” to further investigation being “advised”.

The IET has stressed that periodic inspection and testing is intended to establish whether an installation is suitable for continued use. It is not intended to become a general fault-finding exercise.

This distinction could make a significant difference to the way EICRs are interpreted by property owners, landlords and contractors.

“Isolator” is no longer the preferred terminology

Another relatively small but interesting change concerns terminology.

The word “isolator” has been removed from BS 7671 and is now considered too broad a term for the purposes of the Regulations.

Instead, the standard distinguishes between devices such as disconnectors and switch-disconnectors, depending on their characteristics and intended use.

The IET acknowledges that electricians will probably continue using the word “isolator” on building sites and in everyday conversation.

However, designers and those producing formal documentation should be aware of the terminology used in the latest edition.

Changes affecting switching and isolation

Amendment 4 also updates Table 537.4, which deals with protective, isolation and switching devices.

The revised table includes additional references to devices such as:

* Firefighters’ switches
* Residual direct-current protective devices
* Switched socket-outlets
* Switch-disconnectors

The changes are intended to give designers a clearer choice of equipment while making the different functions of devices easier to understand.

This is particularly relevant to installations incorporating EV charging and other modern electrical equipment.

EV charging and battery systems remain major areas

Although electric vehicle charging is not itself a completely new subject within BS 7671, Amendment 4 needs to be viewed against the rapid growth of EVs, battery storage and renewable generation.

Electrical Safety First says Amendment 4 reflects the changing way electricity is generated, stored and used in homes, where EV charging, battery storage, solar PV and ICT infrastructure are increasingly common.

This means electricians increasingly need to consider an installation as an integrated energy system rather than simply a collection of socket outlets and lighting circuits.

Supporting guidance has also been updated

The changes aren’t limited to the main Wiring Regulations book.

The IET has been updating its supporting publications to bring them into line with Amendment 4. This includes the new ninth edition of the On-Site Guide and updated editions of Guidance Notes covering areas such as:

* Selection and erection
* Isolation and switching
* Inspection and testing
* Protection against fire
* Protection against electric shock
* Protection against overcurrent
* Special locations
* Earthing and bonding

The IET says these publications have been updated to BS 7671:2018+A4:2026.

For electricians using older copies of the guidance, this is an important consideration because simply owning the latest Wiring Regulations book may not provide all of the updated practical guidance needed for day-to-day work.

Changes to wider building regulations

There have also been some recent developments outside BS 7671 that could affect electrical work.

In England, the Government updated Approved Document L during September 2026, including revisions to the guidance covering energy efficiency and greenhouse gas emissions. The September update included corrections to the 2026 editions and new frequently asked questions. ([GOV.UK][7])

The Government has also issued a September 2026 direction concerning fibre-optic cabling in existing non-higher-risk buildings.

From 1 September 2026, certain work involving drilling holes no larger than 25mm through walls for fibre-optic cabling is covered by a specific dispensation from certain Building Regulations procedural requirements.

While this isn’t a change to BS 7671 itself, it is relevant to contractors working on modern communications infrastructure alongside electrical installations.

What electricians should do now

With the 15 October transition deadline approaching, electrical contractors should consider the following:

1. Make sure you have access to BS 7671:2018+A4:2026.
2. Familiarise yourself with the changes rather than simply replacing the old book.
3. Update your inspection and testing procedures.
4. Check EICR documentation and understand the revised FI classification.
5. Review procedures for battery storage and other energy-storage installations.
6. Pay particular attention to EV charging and multiple sources of supply.
7. Update company templates, certificates and documentation where necessary.
8. Make sure staff and apprentices are working from current guidance.
9. Check that supporting publications such as the On-Site Guide and Guidance Note 3 have been updated.
10. Remember that BS 7671 is a standard rather than an Act of Parliament — other statutory requirements, including Building Regulations, still need to be considered.

The big change for October 2026

For most electricians, the most important development over the coming weeks is the end of the BS 7671 transition period.

The IET currently states that BS 7671:2018+A3:2024 remains valid until 15 October 2026. After that date, Amendment 4 becomes the version installers need to be working from. ([IET Wiring Regulations][1])

The changes are much broader than a simple collection of minor amendments. Battery storage, PoE, ICT systems, medical locations, EICR reporting, switching and isolation are all examples of how electrical installations are changing.

With homes increasingly incorporating solar panels, battery storage, EV chargers, heat pumps, smart devices and high-speed communications, BS 7671 is evolving to cover a much more interconnected electrical environment.

For electricians, the message is clear: **the move to Amendment 4 is now very close, and October 2026 marks an important point in the transition to the latest UK Wiring Regulations.**

*This article is intended as a general news and information overview. Electrical work should always be designed, installed, inspected and tested by appropriately competent persons using the current BS 7671 requirements, applicable legislation and manufacturer instructions.*

Key changes to BS 5839-1:2025 – Part 2

Leave a Reply

This was first posted in IET Magazine November 2025.

Main Changes Covered

1. False Alarm Reduction

  • The standard now explicitly highlights the user’s responsibility to investigate and respond to false alarms every time they occur — those commissioning or handing over systems must inform users of this duty.

2. Commissioning and Handover Improvements

  • Before handover, the client or their representative must verify that manual call points have the correct replaceable parts and tools.
  • A cause-and-effect matrix (or equivalent text) explaining how system inputs affect outputs must be provided.

3. Maintenance Changes

  • Routine servicing intervals remain every six months but now allow flexibility of 5–7 months without losing compliance.
  • Control and indicating equipment clocks must be checked/adjusted to ensure accurate event logs.
  • In England & Wales, zone plans must be verified annually to reflect building changes.
  • New cybersecurity clauses require appropriate security measures and authentication to protect systems.

4. Extensions & Modifications

  • A new dedicated section covers how to extend or modify existing fire alarm systems.
  • Extensions must comply with the current standard, even if the original system does not.
  • Redundant devices (e.g., obsolete call points) should be removed or clearly labelled to avoid confusion during emergencies.

5. User Responsibilities

  • If the installation deviates from the standard (e.g., due to compromises in device placement), these variations must now be documented in the logbook, with provided model formats.

Relationship Between BS 5839-1:2025 and BS 7671

The article also clarifies how this fire alarm standard interacts with the UK electrical wiring rules:

  • BS 7671 (IET Wiring Regulations) often references BS 5839 for fire alarm systems under certain regulations.
  • Where differences occur between the two standards regarding fire alarm systems, BS 5839-1:2025 takes precedence.
  • The guidelines emphasise the need for safe isolation — BS 5839 no longer mandates a double-pole isolator, but safe isolation per UK electrical safety regulations remains essential.

Inspection & Testing Notes

  • Although functional testing of fire alarm systems should follow BS 5839-1:2025, electrical inspection and testing (e.g., for certification purposes) remains under BS 7671.
  • Inspectors must clearly agree with clients on what parts of the fire alarm system are included in any electrical inspection report to avoid misunderstandings about coverage.

Overall Message

Staying current with standard changes helps professionals and building duty holders manage fire safety, meet legal obligations, and reduce risk. Specialists should clearly communicate responsibilities, documentation, and limitations of inspections.

Further details – https://electrical.theiet.org/wiring-matters/years/2025/108-november-2025/key-changes-to-bs-5839-12025-part-2/

IET and BSI urges electrical industry to have its say on IET Wiring Regulations

Leave a Reply

The Institution of Engineering and Technology (IET) and BSI are calling on the electrical industry to have its say on an amendment to the current BS 7671:2018 Amendment 2 (2022) + Amendment 3 (2024), which will go to DPC (Draft for Public Consultation) on 7 August 2024. BS 7671 is the Requirements for Electrical Installations: IET Wiring Regulations.

  • Draft for Public Consultation open from 7 August 2024 to 3 November 2024.
  • Latest amendment expected to be published in 2026

The amendment, known as Amendment 4, has been long-scheduled and will incorporate changes to harmonised standards at European level which the UK has to adopt within a certain time period.

The DPC for Amendment 4 is hot on the heels of Amendment 3 which has just been published and is available as a free-to-download PDF ‘bolt-on’ to Amendment 2 from the IET and BSI websites.

Amendment 4 is expected to be published in 2026, until that time electrical installers need to have a copy of Amendment 2 (2022) – the ‘brown book’ and Amendment 3 (2024) free PDF bolt-on to be up to date. Join the IET for a live webinar at midday on Wednesday 7 August 2024 as we announce the proposed changes and how they may affect you.

Comments on the DPC for Amendment 4 can be submitted through BSI’s Standards Development portal between 7 August 2024 to 3 November 2024.

IET’s Mark Coles, Head of Technical Regulations, said: “The days of the ‘evergreen electrician’ are gone. Changes in technology, installation practices and developments in standardisation are happening so quickly. It’s therefore so important that installers and designers stay well-informed of what’s happening in the industry. The IET is the authority for electrical installations in the UK and ensures that the wiring regulations committee, JPEL/64, carefully considers all necessary updates to the Regulations to ensure they best meet the needs of industry.

“It is intended that this Amendment will include requirements for Stationary Secondary Batteries, low voltage generating sets, power over ethernet, energy efficiency and functional earthing and functional-equipotential-bonding for Information and Communication Technology Equipment and Systems (ICT). Each area of change is a response to fast evolving technologies.”

BSI’s Dan Palmer, Associate Director, Committees, said: “BSI is proud to have been partners with the IET for over 30 years.  As electrification increases in the UK, we can all benefit from supporting high standards of safety. Keeping this critical standard on electrical installations updated is vital to ensure continued safety. We urge people with an interest to look at the suggested changes made in the draft and provide your comments.”

The Chair of JPEL/64, Graham Kenyon, said: “The members and officers of JPEL/64 invite anyone involved in the industry to contribute to the standard by providing comments on the Draft. We will initially focus on addressing comments related to the intent of technical changes put forward. Comments made on other parts of the standard will be considered in future work of JPEL/64, both for BS 7671 and international work. I extend personal thanks to all the organisations and individuals that have contributed to this Draft so far, both at National and International level.” 

The IET and BSI jointly manage JPEL/64, the committee responsible for BS 7671.

Can I install a metal consumer unit with a TT earthing system?

Leave a Reply

High earth fault loop impedance values associated with TT earthing systems mean the earth fault current level is unlikely to be sufficient to operate the distributor’s protective device within the permitted time of 1 second, as required in Regulation 411.2.4, or at all in some cases, depending on Earth resistance values.

There is nothing to prevent a metal consumer unit being installed with a TT earthing system, but it’s important to ensure that an earth fault cannot develop between the meter tails and the metallic enclosure before the RCD.

Methods of reducing an earth faults include keeping the meter tails as short as possible, the installation of proprietary clamps and glands to secure the cables and prevent strain on the terminations, minimising the risk of damage to the meter tails and a subsequent earth fault.

Amendment number 1 to BS 7671:2018+A1

Leave a Reply

Amendment 1 of BS 7671:2018 was published at the beginning of February this year and may be implemented immediately. The amendment concerns Section 722 of BS 7671:2018 (electric vehicle charging installations). In this article, we give a brief overview of some of the main changes to Section 722.

Protection against electric shock

Regulation 722.411.4.1 concerning the use of protective multiple earthing (PME) supply has been redrafted. Indent (iii) has been fully revised. In addition, Regulation 722.411.4.1 now includes an additional indent (iv) to cover single-phase installations and a further additional indent (v) has been added. Regulation 722.411.4.1 does not allow PME to be used to supply an electric vehicle (EV) charging point located outdoors (or that might be used to charge a vehicle located outdoors) unless you meet (i) or (ii) or (iii) or (iv) or (v) of 722.411.4.1.

A summary of the requirements of the indents to Regulation 722.411.4.1 is as follows.

Regulation 722.411.4.1(i) refers to a situation where a connecting point is supplied from a three-phase installation used to supply loads other than charging points and where the load is sufficiently well balanced.

Regulation 722.411.4.1(ii) requires a very low resistance earth electrode to mitigate the effects of an open-circuit (PEN) conductor fault on the supply.

Regulation 722.411.4.1 (iii) has been revised and refers to a voltage monitoring device (or functionality within the charging equipment) that detects PEN conductor failure. The informative Annex to Section 722 describes that suitable arrangements include measurement of the voltage between either:

   a. the circuit protective conductor (CPC) and a suitable measurement earth electrode, or
   b. the CPC and a reference point derived from the line conductors of a three-phase system provided that suitable precautions are also taken to disconnect the device when the supply to one or more of the line conductors is interrupted.

Regulation 722.411.4.1 now includes an additional new indent (iv) to cover protection by a device (or functionality within the charging equipment) for a single-phase installation.

Finally, Regulation 722.411.4.1 includes an additional new indent (v), which allows protection against electric shock to be provided by the use of an alternative device to those in (iii) or (iv), providing that it does not result in a lesser degree of safety than using (iii) or (iv). The indent states that equivalent means of functionality could be included within the charging equipment.

The touch voltage threshold of 70 V mentioned in Regulation 722.411.4.1 is on the basis that Table 2c (ventricular fibrillation for alternating current 50/60 Hz) of IEC 60479-5{ed1.0} gives a value of 71 V for both-hands-to-feet, in water-wet conditions with medium contact area (12.5 cm2).

Regulation 722.411.4.1 includes some important notes. Note 5 explains that BS 7671 does not deal with the safety requirements for the construction of electrical equipment. Where equipment to be used is not covered by a British or Harmonized Standard, the electrical installation designer should establish that the manufacturer of the equipment has ensured that the equipment satisfies the safety objectives of the relevant directive(s).

Note 6 states that creating a TT earthing system for charging equipment or for the whole installation, as an alternative to using a PME earthing facility with one of methods (i) to (v) above, may not be an appropriate solution, due to the inability to provide sufficient separation from buried metalwork connected to the supply PEN conductor.

What is protective multiple earthing (PME)?

The Electricity Safety, Quality and Continuity Regulations 2002 (ESQCR) (as amended) permit the distributor to combine neutral and protective functions in a single conductor, provided that (in addition to the neutral to Earth connection at the supply transformer) there are one or more other connections with Earth. The supply neutral may then be used to connect the CPCs of the customer’s installation with Earth if the customer’s installation meets the requirements of BS 7671.

PME has been almost universally adopted by distributors in the UK as an effective and reliable method of providing their customers with an earth connection. Such a supply system is described in BS 7671 as TN-C-S. However, whilst a PME terminal provides an effective and reliable facility for the majority of installations, under certain supply system fault conditions (external to the installation), a potential can develop between the conductive parts connected to the PME earth terminal and the general mass of Earth.

The potential difference between true Earth and the PME earth terminal is of importance when:

   a. body contact resistance is low (little clothing, damp/wet conditions), and/or
   b. there is relatively good contact with true Earth. 

Contact with Earth is always possible outside a building and, if exposed-conductive-parts and/or extraneous-conductive-parts connected to the PME earth terminal are accessible outside the building, people may be subjected to a voltage difference appearing between these parts and Earth.

Residual current device (RCD) protection

The requirements for RCD protection have been redrafted. The Regulation now contains further requirements for Type B and Type A or Type F RCDs, to take account of DC fault current, as follows (extract below):

“Except where provided by the EV charging equipment, protection against DC fault currents shall be provided by:

(i) an RCD Type B, or

(ii) an RCD Type A or Type F in conjunction with a residual direct current detecting device (RDC-DD) complying with BS IEC 62955 as appropriate to the nature of the residual and superimposed currents and recommendation of the manufacturer of the charging equipment.”

ANNEX A722 (Informative)

Annex A722 has been redrafted. This Annex now includes guidance on the voltage monitoring device described in Regulation 722.411.4.1 (iii). In addition, the Annex now includes an example arrangement of a separated system as described in Regulation 722.413. 

Conclusion

It is important to note that this article gives only a very brief overview of some of the changes in the Amendment to BS 7671:2018. For more information, please refer to BS 7671:2018, Amendment 1:2020.

By: Geoff Cronshaw – IET Wiring Matters – Issue 79