Kevin McCloud follows Matt and Sophie White from Sussex as they build a giant family house of fun for themselves and their children. Going against the norm of designing a serious and practical home, the couple's property features a revolving bookcase door, secret dens, hiding places, one-way mirrors, and a fireman's pole. Matt uses a steel frame system to allow them to change the layout of the property, and other changes include amending the window shapes and sizes, and adding a half floor to create a James Bond room.