In this final episode, Kevin exclusively reveals the winner of the most prestigious prize for residential architecture, the Riba House of the Year 2018. But first, alongside architect Damion Burrows and design expert Michelle Ogundehin, he explores the last group of houses on the long list. Each one uses materials in interesting ways. In leafy Berkshire, there's a perfectly crafted timber box, with sleek concrete floors and giant six-metre windows. In Belfast, there is a small but perfectly formed house with black larch cladding. In Surrey, a completely revamped 1930s house with a pale brick and glass modernist extension blends beautifully into its setting. And finally, an experimental house in London makes the materials it's built from part of the design. Kevin then reveals which of these properties has made it onto the shortlist before exclusively announcing the overall winner of House of the Year.