It's the final of The Great Interior Design Challenge, and after starting with 27 amateur interior designers, only two remain. Now they are each out to prove they are the best. To win the title each designer must complete their final challenge; but this time it isn't just one room scheme, but three rooms each in a Stately Home. A 19th century calendar house in Cumbria is the setting for this design showdown, now converted into individual apartments, where our designers will be taking on a living room, a kitchen and a bedroom each, with just £4000 and four days. Our first finalist is given the task of organising a lot of clutter; adding arts and crafts style to the living room, giving a country look to the kitchen, and being given free rein in the guest room. But will they get each look right and impress the judges? Meanwhile their rival designer has been asked for a traditional and elegant look in the living room, a shaker-style in the kitchen and a restful master bedroom. Can they prove they've developed a signature style, without relying on design clichés? Architectural Historian Tom Dyckhoff explains the unusual design behind this grand Calendar house, where each architectural detail is related to numbers in the calendar – 365 panes of glass representing days of the year, 52 chimneys representing the weeks and 12 corridors representing months of the year. Meanwhile judges Sophie Robinson and Daniel Hopwood must decide which designer has created the best schemes, and deserves to be named champion.