Mahendra Mistry from Bureau Veritas untangles any doubts surrounding the UK Wiring Regulations’ 18th Edition

While it’s not unusual to see new regulations bring in new requirements, the 18th Edition will constitute one of the biggest shake-ups to the UK Wiring Regulations to date – with energy efficiency introduced for the very first time.



ith this brings a renewed focus on the energy efficiency plight and the integral role that the modern contractor has to play in helping customers to reduce their energy use and carbon footprint while, in turn, boosting their green credentials. While this, of course, requires a new mindset and applied learning for the busy contractor, it will pay dividends in the long-run. Here Mahendra Mistry, Technical Manager for Electrical Systems at Bureau Veritas, tells you what you need to know.

The advent of sustainability is undoubtedly transforming the role of the modern contractor. Today, the task is to not only ensuring that all electrical systems and equipment are in safe and working order to support the core business of an organisation cost-effectively, but also to ensure it operates in the most energy-efficient manner possible.

Currently, non-domestic buildings in the UK account for 17% of our energy consumption and 12% of greenhouse gas emissions1. Thereby a majority proportion of our green economy lies with the UK’s business and industry; particularly as they are usually bigger premises than domestic properties, so energy efficiency measures are more cost-effective.

This is seen in a raft of green initiatives and legislation with the Energy Savings Opportunity Scheme (ESOS), the ErP Directive, Energy Performance Certificates, the CRC Energy Efficiency Scheme, the Waste Resources Action Plan (WRAP), and more.

The result is that the UK’s businesses need to get serious about their energy and increasing onus is being placed on the contractor who must play a major role in this transition by developing in-depth knowledge of the latest green products and solutions.

Yet until this point, there has been no official best practice regulation around the design and installation of energy-efficient technology – meaning it has been all too common for installations to be chopped and changed, with little regard to the distribution of electricity or potential losses.

Cue the arrival of the 18th Edition this July, which, for the very first time, goes beyond just looking at solely safety requirements to include a new section designed to ensure energy efficiency is incorporated into electrical installation designs as a prerequisite rather than just as a ‘nice-to-have’.

Comprising 25 pages of expert guidance, the new Part 8 takes a different approach to electrical installations, with a view to lessening environmental impact, reducing energy losses and, in turn, energy costs, using energy only when required and potentially at a lower tariff, reducing maintenance by ensuring equipment is installed correctly and enhancing general lifetime efficiency.

Key energy efficiency performance measures include lighting and the benefit of replacing traditional standard filament, halogen and fluorescent lights with super-efficient LEDs as one of the easiest ways to cut energy costs.

Equally, power factor correction is covered, being an increasingly sought-out energy-efficient measure which employs the use of high-quality, reliable capacitors that compensate for any reactive non-working reactive power demand; restoring power factor as near to unity as possible.

Further measures included in Part 8 include guidance around the best practice installation of transformers and cables, with a view to negating losses through the installation of more energy-efficient models supported with a strategic design, alongside with guidance on smart metering, load balancing and harmonics, and more.

Although all of this, of course, is nothing new – it is a clear sign of the times and the growing sense of urgency around energy-efficient technology and smart installations – and the good news for the electrical contractor in-the-know is greater demand for smart solutions driving new business opportunities.

As such, the recommendation is for contractors to invest time and resource into familiarising themselves with Part 8, along with the wider 18th Edition and the changes it brings. Indeed, it may mean time off the tools and extra training, but the likelihood is it will pay dividends in the years to come.

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