 The extension was also listed for a 2007 RIBA award.It is believed to be the first art gallery in the UK which is heated and cooled by a geothermal system, using water pumped through 69 pipes descending 35 metres under the building, connected to reversible heat pumps, which roughly halves its carbon emissions.To the rear is a new courtyard garden, designed by Christopher Bradley-Hole, a Chelsea Flower Show gold medallist.