Kevin McCloud meets Audrey and Jeff, who dream of living in one of west London's most exclusive areas. However, the way they can afford it is to go underground. Their plan is to transform a listed Edwardian artist's studio - along with 5,000 sq ft of derelict basement - into a bespoke subterranean home, complete with supersize kitchen, mezzanine sitting room, four en-suite bedrooms, a gym, cinema, steam room and wine cellar. As if the task weren't tricky enough, they are doing it without proper architect's drawings and Audrey is project managing - and the difficulties begin almost from the start.