BS 7671 18th edition wiring regulations

BS 7671 18th Edition Wiring Regulations


Calbarrie’s Tim Beardsmore explains how the introduction of the 18th Edition of the BS 7671 Wiring Regulations expected in July may affect FM processes.    

Next month the 18th Edition of the British Wiring Regulations is due to be published setting the standards that all new electrical installations will have to meet. The proposed regulations are expected to be fully effective from 1 January 2019. Before then facilities managers can start to develop an understanding of how the proposed changes differ from the existing regulations and the likely impact the changes will have on facilities management processes.

The Institution of Engineering and Technology (IET) publishes the Wiring Regulations with the British Standards Institution (BSI). The regulations are designed to ensure that electrical installation work meets the requirements of the Electricity at Work Regulations 1989. A number of factors have driven the need for change including recent updates to European and International standards and a growing responsibility for all of us to consider the environmental impact of the buildings we construct and manage and the energy levels they consume.

Some of the expected changes that electrical contractors will be required to understand and adhere to are outlined below.

411.3.1.2 No requirement to bond water main where incoming pipe is PVC

411.3.3 30mA RCD protection to be provided for all socket outlets up to 32A with no exemptions permitted.

This is a new requirement and will mean that in an office with dedicated IT sockets, for instance, if an additional socket is required then the whole circuit will require RCD protection. So FMs should consider limiting the number of workstations per circuit and even adding another circuit to reduce the risk of the RCD tripping.

421.1.7 Arc Fault Detection devices may be used as additional protection against fire

433 & 534 Increased use of Surge Protection Devices and the correct selection of appropriate devices

521.10 Metallic containment on wiring now applies to all areas not just escape routes

We are expecting further clarification on the regulations relating to wiring systems in escape routes, and a requirement for metallic containment on wiring to apply to all areas not just escape routes to prevent the premature collapse in the event of fire. This will ensure that in an event of fire or collapse no cabling is left hanging and dangerous for evacuees or emergency services.

542.1.201 Earth electrodes to be installed to all supplies regardless of type of earth system

An important new requirement is for earth electrodes to be installed to all new installations regardless of age, condition and type of earthing system. This will ensure that the electrical network to the building maintains a protective conductor even if the electrical network provider’s earth fails.

Part 8 Energy Efficiency

A proposed new chapter provides additional design and construction requirements for the efficient use of electricity and, for the first time, BS 7671 includes requirements which are not intended to protect life and property. The proposals consider how design and installation practices can impact electricity consumption whilst meeting required safety and service standards, and electrical installations can be awarded energy efficiency points and given an overall efficiency rating. Customers will be able to specify certain energy efficiency features in the installation such as lighting control modules, smart metering and electric vehicle charging points.

Appendix 6 Inspection and Testing

FMs are likely to see some change to the condition report inspection schedule with the addition of a column to indicate the voltage being used to test a circuit. This is possibly in response to the number of low voltage electronic devices such as PIRs, control modules and dimmer switches now being found within the circuit.

Until the proposals for the new regulations are finalised and fully effective we should continue to work to the 17th Edition. Electrical contractors will be able to advise what impact the proposals are likely to have on specific FM processes, and how FMs can best prepare. Further information on the new regulations is also available from the IET at and the NICEIC at

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