Conversion work is now underway in order to transform a Listed courtyard of buildings in the grounds of a Queen Anne-style house in Oxfordshire into an environmentally sustainable mixed development comprising offices, residential units and serviced short-stay accommodation.

The buildings will look substantially inward towards a landscaped parking area and the opportunity is being taken to introduce five ground source heat pumps served by twelve borehole collectors located within this central space.

Working in this instance with Worcester Bosch Group, specialist drilling contractors and heat pump installation engineers RPA Architects aim wherever possible to coordinate the pursuit of sustainable energy technologies which avoid environmental damage. Unlike solar thermal panels which require boiler back-up, heat pumps can in many circumstances provide all of the heating and hot water required.

Geothermal boreholes are drilled by lorry-mounted or small-track drilling rigs, their depth being determined by geological prognosis and calculation of demand. With rigs on site for this purpose it is often possible, as in this instance, to drill additional boreholes in order to deliver natural untreated water to the surface via a small submersible pump within the well casing. Subject to laboratory analysis this supply is frequently fit for drinking purposes without filtration or UV treatment, and up to 20 cubic metres can be extracted per day free of charge.