Geothermal energy systems are heating up, so to speak, evidenced by projects such as Fletcher Priest Architects’ Eastbourne Terrace, in which several systems were used. Increasing implementation owes to both the popularity of renewables, and to recent policy changes including measures like the Merton Rule – a guidance originated in the London Borough of Merton and that requires new developments supply 10 per cent of their energy through on-site renewable sources.
For its refurbishment of Eastbourne Terrace – five 1960s office blocks opposite London’s Paddington Station, the architect chose to use a series of geothermal boreholes (also called ground-source heat pumps), which see pipes circulating water sunk into the ground beneath the development, using the Earth as a heat source in winter and a heat sink in summer. Although the technology of these systems has existed for a long time – ‘even Harrods has one’, notes Fletcher Priest project director Stephen Barton – even as of a few years ago there were relatively few. As of October 2007, Environment Agency data shows that some 140 geothermal schemes were proposed, under construction or operational in London alone.