For Underground House, we installed a 46kW Vaillant Geotherm ground source heat pump connected to 11 x 100m boreholes. The heat pump feeds a 1000 litre buffer tank which in turn heats 1000m² of office space via over-sized radiators – the plant room sits in the shadows of a 50kW Endurance wind turbine and within 100m of a 50kW ground mounted solar PV array – Trevissome Park will soon be Cornwall’s first ever business to achieve 100% carbon neutral status!