Grand Designs: House of the Year (2015) : 3x3

Kevin McCloud, architect Damion Burrows and magazine editor Michelle Ogundehin review homes in the country. There's a luxurious tree house in Dorset that shows off the wonder of wood, and an awe-inspiring cantilevered concrete home on the Isle of Purbeck, with floor-to-ceiling glazing. Plus, a property with a cluster of zinc-clad boxes imitating local traditional Scottish farmsteads, and a 17th-century Devon barn that's been sensitively restored for modern living. But which will be shortlisted for the Royal Institute of British Architects House of the Year 2017?