Kevin McCloud, Damion Burrows and Michelle Ogundehin visit five properties demonstrating exceptional use of materials and craftsmanship. They include a bold contemporary barn, forged from corten steel and concrete, a small urban house squeezed into a plot the size of a London Tube carriage, and a Scandi-Scottish lochside bolthole, hewn from Highland stone and Danish oak. The others are a wooden wonderland extension in east London and a Surrey home with an extraordinary engineered timber roof