
For estates teams managing large public or commercial buildings, energy strategy has become a boardroom concern. Heating and cooling infrastructure - historically seen as a behind-the-scenes operational concern - is now under scrutiny for cost, compliance, and future fitness.
Legacy systems are driving up operational costs and exposing estates to financial risk. New standards like MEES (Minimum Energy Efficiency Standards) now prevent leasing commercial buildings rated below EPC “E”, yet over 13,000 properties in England and Wales are still rated F or G. Efficiency gaps now put asset value, tenant retention and reputation at risk - especially as carbon performance becomes a visible benchmark.
At the same time, energy prices remain unpredictable and demand is set to rise sharply as the grid decarbonises. Buildings already account for 25% of the UK’s total carbon footprint. Reducing that load - and doing so cost-effectively - is fast becoming a priority for any estate that wants to stay future-proof.
Ground source heat pumps (GSHPs) use the stable temperature beneath the ground to provide both heating and cooling - efficiently, reliably and without visible infrastructure.
Far from a niche technology, GSHPs are already operating at scale across a range of public and commercial estates. In Central London, Onsen delivered the drilling phase for a large-scale retrofit spanning over 400 homes, demonstrating how GSHP infrastructure can be installed safely and effectively in dense urban environments. At a multi-campus secondary school and college site, a new GSHP system was integrated to support long-term energy efficiency and carbon reduction across diverse building types - all delivered within a live educational setting.
For estates teams managing large or complex portfolios, these projects show what’s possible: year-round system performance, minimal disruption during the install and running costs that can be forecast with confidence. And with guidance from UKGBC and others now recommending systems-level retrofits over fabric-only upgrades, GSHPs are increasingly seen as a dependable route to long-term efficiency and compliance.

For estates teams planning major upgrades or futureproofing against compliance risk, GSHPs offer a rare combination:
In short, for estates navigating today’s energy, compliance, and budget pressures - ground source isn’t a gamble; it’s a proven path to lower risk and higher resilience.
For estates under pressure to cut running costs, meet compliance targets, or futureproof their energy systems, ground source heat is an option worth exploring - and a quick call is the easiest way to explore whether it’s right for your site.
In a 10-minute call, we can:
There’s no pressure to commit - just practical advice from a team that delivers this kind of work on real sites every day.
Email gareth@onsenenergy.com and let’s see if GSHP could work for your estate.