Kevin McCloud meets Mark and Candida Diacono, who have set about building a home in the shape of a plough on their 17-acre smallholding in Devon. With its complex curved roof, timber-clad exterior and steel-framed working barn, the ambitious project presents a unique technical challenge for a local builder and his team of employees, and the task proves even more intimidating when considering Mark and Candida hope to complete work on the build within seven months.