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18th Edition changes


BS 7671:2018+A2:2022 Requirements for Electrical Installations was issued on 28 March 2022 and may be implemented immediately.

BS 7671:2018+A1:2020 remains current and will be withdrawn on 27 September 2022.

The Regulations apply to the design, erection and verification of electrical installations, also additions and alterations to existing installations. Existing installations that have been installed in accordance with earlier editions of the Regulations may not comply with this edition in every respect. This does not necessarily mean that they are unsafe for continued use or require upgrading.

Contractual and legal considerations

This publication does not purport to include all the necessary provisions of a contract. Users are responsible for their correct application.

Compliance with a British Standard cannot confer immunity from legal obligations.

NOTE 1: Completion of an electrical installation designed to the withdrawn standard can be subject to the contractual agreement between all parties involved.

NOTE 2: BSI publishes information on the uses of withdrawn British Standards.

A summary of the main changes is given below.

NOTE 3: This is not an exhaustive list.

Part 1 - Scope, Object and Fundamental principles

Minor changes have been made including reference to prosumers electrical installations and installing fibre optic cables.

Part 2 - Definitions

Definitions have been expanded and modified.

Chapter 41 Protection against electric shock

Section 411 contains a number of significant changes. Some of the main changes are mentioned below.

Regulation 411.3.1.2 has been redrafted. The regulation now requires that in each consumer’s installation within a building extraneous-conductive parts that are liable to introduce a dangerous potential difference be connected to the main earthing terminal.

A note has been added clarifying that where non-metallic pipes, e.g. plastic, enter the building and are then connected to metallic pipes within the building, the metallic pipes within the building do not normally require protective bonding as they are unlikely to be extraneous-conductive-parts. Reference to insulating sections has been removed.

Regulation 411.3.3 has been redrafted and now has three indents. There is still an exception to omit RCD protection where, other than BA1, BA3 or children (BA2, BA3) and mobile equipment (not exceeding 32 A) for use outdoors, a suitably documented risk assessment determines that RCD protection is not necessary.

Regulation 411.4.2 now recommends an additional connection to Earth, by means of an earth electrode in accordance with Chapter 54, is made to the main earthing terminal.

Chapter 42 Protection against thermal effects

Regulation 421.1.7 has been redrafted. It is now a requirement to protect final circuits supplying socket-outlets with a rated current not exceeding 32 A using arc fault detection devices (AFDD) in Higher Risk Residential Buildings, Houses in Multiple Occupation, Purpose-built student accommodation and Care homes. For all other premises, the regulation recommends AFDDs for single-phase AC final circuits supplying socket-outlets not exceeding 32 A. The use of AFDDs does not obviate the need to apply one or more measures provided in other clauses in this standard.

Regulation 422.1 (precautions where particular risks of fire exist) now introduces requirements for the fire safety design of the building(s) to be documented. Also, requirements have been added where cables should have an improved fire performance.

Regulation 422.2 now introduces separate requirements for escape routes and a new concept of 'protected escape routes'. Reference to conditions BD2, BD3 and BD4 has been deleted.

Chapter 44 -  Protection against voltage disturbances and electromagnetic disturbances

Regulation 443.4 for determining if protection against transient overvoltages is needed has been redrafted. Regulation 443.4.1 now requires protection against transient overvoltages to be provided where the consequence caused by the overvoltage could result in:

  • serious injury to, or loss of, human life
  • failure of a safety service, as defined in Part 2
  • significant financial or data.

For all other cases, protection against transient overvoltages shall be provided unless the owner of the installation declares it is not required due to any loss or damage being tolerable and they accept the risk of damage to equipment and any consequential loss.

Regulation 443.4.2 requires protection against overvoltages to be considered in the case of equipment likely to produce switching overvoltages or disturbances and gives conditions.

Regulation 443.5 (Risk assessment method) has been deleted and Annex A443 (examples of calculated risk level CRL for use of SPDs) has also been deleted.

Section 514 - Identification and notices

Section 514 contains a number of significant changes (including illustrations of notices which have been removed and examples are provided in Appendix 11). Some of the main changes are mentioned below.

Table 51 has been modified slightly to take into account changes of colour identification for DC and abbreviations have been added.

Regulation 514.9.1 now contains an exception for domestic (household) premises.

Regulation 514.9.2 has been introduced to advise that all diagrams, charts, and information or instruction notices comply with the applicable standards specified.

Regulation 514.12 (Notices: periodic inspection and testing) now contains an exception for domestic (household) premises in certain situations.

Regulation 514.12.2, concerning the RCD notice, has been modified and now contains an exception for domestic (household) premises in certain situations.

Regulation 514.14 concerning non-standard colours has been deleted.

A new Regulation 514.16.1 has been introduced requiring a label to indicate the presence of SPDs. However, there is an exception for domestic (household) premises or similar.

Chapter 53 - Protection, isolation, switching, control and monitoring

Regulation 531.3.2 indent (ii) highlights the use of RCBOs for individual final circuits in residential premises to

minimise unwanted tripping.

Regulation 531.3.3 now states that RCD Type AC shall only be used to serve fixed equipment, where it is known

that the load current contains no DC components.

Chapter 54 - Earthing arrangements and protective conductors

Modifications have been made to Regulation Group 543.7 concerning earthing requirements for the installation of equipment having high protective conductor currents.

Regulation 544.1.1 concerning main protective bonding conductors has also been revised.

Chapter 55 - Other equipment

551.7 Additional requirements have been added for installations where the generating set or sets may operate in parallel with other sources including systems for the distribution of electricity to the public.

551.7.2 includes additional conditions.

554.4 Heating conductors and cables Regulations 554.4.2, 554.4.3, and 554.4.4 have been deleted.

Chapter 64 - Initial verification

Regulation Group 643.3 has been redrafted. The requirements for testing insulation resistance where equipment is likely to influence the verification test or be damaged has been clarified and reference is made to a 250 V DC test following the connection of equipment.

The requirements for RCD testing have been changed and Table 3A (Time/current performance criteria for RCDs) in Appendix 3 has been deleted. Regardless of RCD Type, an alternating current test at rated residual operating current (IMn) is used to verify the effectiveness.

Section 702 - Swimming pools and other basins

Regulation, 702.414.3, concerning SELV and PELV, has been introduced.

Section 703 - Rooms and cabins containing sauna heaters

Regulation 703.414.3, concerning SELV and PELV, has been introduced.

Section 704 -  Construction and demolition site installations

Regulation 704.511.1 includes changes to plugs and socket-outlet requirements. Changes have also been made to requirements for wiring systems (704.52) and the requirements for devices for isolation have been redrafted (704.537).

Section 706 - Conducting locations with restricted movement

The requirements for protection against electric shock have been completely redrafted. A new Regulation 706.415, requirements for additional protection, has also been introduced.

Section 710 - Medical locations

Changes include requirements concerning socket-outlet circuits in the medical IT systems and minor changes to requirements concerning luminaires and lighting installations. Also, requirements concerning diagrams and documentation have been changed.

Requirements for IT systems have also been redrafted. Changes also include requirements for fault protection and requirements for protective equipotential bonding.

Section 711 Exhibitions, shows and stands

A new Regulation 711.410.3.101 has been introduced. It sets out the requirements for all final circuits, other than those of safety services, having a rated current not exceeding 32 A supplying socket-outlets or handheld electrical equipment, and all final circuits for lighting to use either automatic disconnection of supply (with additional protection by means of an :S30 mA RCD), SELV or PELV, or electrical separation. Regulation 711.42 concerning protection against thermal effects has been deleted. Requirements for isolation and switching have been redrafted. In addition, the regulations covering luminaires and lighting installations have been redrafted.

Section 712 - Solar photovoltaic (PV) power supply systems

The technical content of this section has been extensively revised and expanded. Requirements of this section now apply to:

  • PV installations not connected to a system for distribution of electricity to the public,
  • PV installations in parallel with a system for distribution of electricity to the public,
  • PV installations as an alternative to a system for distribution of electricity to the

Section 714 - Outdoor lighting installations

This section includes changes to automatic disconnection of supply and additional protection.

Section 717 - Mobile or transportable units

Regulation 717.411.4 has been expanded to take account of PME.

Section 722 - Electric vehicle charging installations

This section incorporates BS 7671:2018+A1:2020 together with other changes, such as, taking account of prosumer’s electrical installations (722.826.3.201). Indent (i) of Regulation 722.411.4.1 has been deleted, also changes have been made to the notes in particular the one concerning where equipment to be used is not covered by a British or Harmonized Standard. In addition, the Annex to 722 has been redrafted and includes guidance on indent (iii) of Regulation 722.411.4.1.

Section 753 - Heating cables and embedded heating systems

Changes include the addition of new regulations (relocated from Chapter 53) covering the impact and the installation of heating cables.

Chapter 82 - Prosumer’s low-voltage electrical installations

This is an entirely new chapter. Historically, utility companies have managed the public transmission and distribution network from the point of view of having central production adapted to demand variation. The objective of this chapter is to provide requirements, such that, low-voltage electrical installations are compatible with the current and future ways to deliver safely the electrical energy to current-using equipment either from the public network or from other local sources.

Chapter 82 provides additional requirements, measures and recommendations for design, erection and verification of all types of low voltage electrical installations. This includes local production and/or storage of energy in order to achieve compatibility with existing and future ways to deliver electrical energy to current-using equipment or to the public network by means of local sources. Such electrical installations are designated as Prosumer’s Electrical Installations (PEIs).


The following main changes have been made within the Appendices:

Appendix 3 Table 3A, covering the tripping times of RCDs, has been deleted.

Appendix 4 includes minor changes concerning a cable surrounded by thermal insulation.

Appendix 6 Model forms for certification and reporting

Minor changes have been made to the model forms and guidance for recipients. These include the addition of fields

for recording the details of SPDs and AFDDs.

The schedule of inspections has been simplified for initial verification. A new example checklist of items requiring inspection during initial verification has been added to Appendix 6 but is not required to be provided with the certificate.

The single-page generic schedule of test results used for EIC and EICR has been redrafted. There is now a separate page for the schedule of circuit details and a separate page for the schedule of test results.

Appendix 7 Deleted by BS 7671:2018+2022


Appendix 11 Warning and user instruction labels

This is a new appendix that provides guidance for the types of safety signs, warning signs and instructions required to be applied to electrical installations.

Appendix 13 Escape routes and fire protection

The previous content of Appendix 13 concerning methods for measuring the insulation resistance/impedance of floors and walls to Earth has been removed and replaced by guidance on escape routes and fire protection. The new content of Appendix 13 provides detailed guidance on protected escape routes in order to afford a safe passage through the building to an exit.

Appendix 17 Energy efficiency

This appendix includes changes to the scope to cover dwellings and reference to the Building Regulations, changes to user decisions, also new design recommendations, new information on the determination of meshes, new information on user requirements, new guidance covering impacts on the design of an installation, and new guidance on periodic assessment.