Horse Box, Milk Float and Balancing Barn

George meets a woman who wants to build a shop and a mobile home out of an old horsebox, but she only has £500 to spend. He meets a couple who are creating a holiday let out of a 1960s milk float. He visits an extraordinary 100-foot-long balancing barn, half of which is hanging over the edge of the Sussex countryside. And George and William make plans for a rectangular pod for their tree house.