It's the seventh of our nine heats and three new designers battle it out for a place in the second round and the chance to win The Great Interior Design Challenge.This time the amateurs are redesigning large open plan reception rooms in three 21st century Eco Homes in Greater London. With just three days and £1250, the amateur designers must deliver gorgeous rooms using materials sympathetic to the eco ethos. Australian born Honor must put aside her love of everything white, as her homeowners prefer a darker, moodier palette. Fashion design graduate Alex gets his screen printer out to give his Manhattan loft design a geometric feel. While B+B owner Jane risks losing the confidence of her homeowners with her clashing colours. Architectural Historian Tom Dyckhoff reveals the ingenious design behind these futuristic, energy-saving buildings. While judges Sophie and Daniel must scrutinise the designers' every decision before they can decide who deserves to go through to the next round.