Kevin McCloud meets a pair of civil-partnered university professors who have decided to build their first home from scratch. In addition to all the complications this usually entails, Celia Brackenridge and Diana Woodward have also enlisted the services of industrial designers who have developed a new computer-assisted method for cutting precision-engineered building blocks from scratch. However, though the technique may be clever, its creators have never created a building before - meaning everyone involved with the project is taking a giant leap into the unknown.

Kevin McCloud follows Lysette and Nigel Offley, who are knocking down an old Thames boathouse and constructing a cutting-edge home in its place. Taking inspiration from the river itself, they have designed a building of waves and curves with a huge glass porthole for a roof light. But problems begin almost from the start, as they can't find a contractor willing to build over the water, their architect leaves unexpectedly and the costs turn out much higher than expected. To make matters worse, the neighbours aren't happy about such a radical sight in their traditional community. As they begin to compromise, Kevin wonders if the couple's dreams will ever be realised.