It's the semi-final, where three designers try and secure their place in the grand final. The challenge they have to conquer in order to get there is redesigning a sitting room each on a medieval terrace in the grand Cathedral city of Wells, in Somerset. Judging them as ever are Sophie Robinson and Daniel Hopwood, but for this semi-final decision they have invited along another guest judge – designer and entrepreneur Orla Kiely. The three designers are being tested like never before in these grade 1 listed cottages, with tight restrictions on what they can and can't do. Their budget is slightly higher at £1500 but with the increase come higher expectations from the judges. One designer is seriously out to impress, attempting difficult trompe l'oeil paint effects in their kitsch take on a hunting lodge scheme. The second semi-finalist takes on an intricate mural design across the walls and ceiling, which they will have to execute to perfection in order to impress. Meanwhile the last designer is going all out, answering their colourful, French Chateaux style brief with bright orange walls, black furniture and ornate pink sofa, which could be a risk too far. One top of this, each designer must impress with a surprise challenge. They'll be given the same item they were asked to upcycle in the first round to test how much they've improved throughout the competition. Meanwhile architectural historian Tom Dyckhoff discovers hidden medieval murals and looks at what life was like when these dwellings were originally built. As for who will go through to the grand final, the judges and Orla have a big decision to make.