HPA UK publishes Version 5 of closed loop vertical borehole standard with CIBSE backing

The Heat Pump Association UK (HPA UK) has published Version 5 of its Closed Loop Vertical Borehole Standard, the first updated technical standard it has released since the Ground Source Heat Pump Association (GSHPA) merged into it earlier in 2026.

The trade body announced the publication on 26 October. The standard covers the design, installation and maintenance of vertical boreholes for closed loop ground source heat pump systems, and HPA UK said it is aimed at engineers, installers and other professionals involved in specifying and delivering such systems.

The Chartered Institution of Building Services Engineers (CIBSE) has endorsed the updated edition, according to HPA UK.

Chris Davidson, Lead Author and Chair of the HPA UK Standards Sub-Group, led the update in collaboration with other industry experts. He said: "It provides engineers and installers with a clear, consistent framework to support high-quality design, installation and operation of vertical borehole systems."

What the standard covers

HPA UK described vertical boreholes as the interface between the heat pump and the ground, and said they play a key role in determining system performance, efficiency and longevity. The body said the revised standard reflects current best practice and technological advances, and provides a framework that promotes health and safety, environmental protection, system longevity and reliable outcomes for consumers.

CIBSE's Knowledge Portal lists an earlier GSHPA edition of the document as a concise specification covering materials and the general specification of a closed loop vertical borehole system.

Ahmed Hegazi, CIBSE Head of Knowledge and Digital, said: "Boreholes are hard to fix once installed, so getting design and installation right first-time matters."

Why it has been revised now

HPA UK said the publication follows its recent recommendations paper, Accelerating the Deployment of Heat Pump Driven Low Carbon Heat Networks and Drilling, which identified a review of the Closed Loop Vertical Borehole Standard as a key priority for the sector.

The body describes itself as the united voice of the heat pump sector. Its about page credits its chief executive with leading a three-way merger to establish HPA UK.

Availability and what comes next

The standard is available now through HPA UK. It is free of charge to HPA UK members on request and can be bought by non-members for £125 plus VAT.

HPA UK's standards page states that all of its standards are free to members, and that further standards will be added as they are reviewed and updated. At present the Closed Loop Vertical Borehole Standard is the only document listed on that page.