The architect visits a life-changing family camper van built for a mum who has tetraplegia and her son who has cerebral palsy. George also returns to a previous Amazing Spacer to see his latest eccentric project - an impressively engineered build, inspired by a cupcake. He then visits Portugal's thinnest house, squeezed between two grand churches, supposedly built to keep apart the nuns from one church and the monks from the other. Plus, three great eco builds including a super-sustainable house created from more than 600 self-assembly wooden blocks, and a swanky riverside house built on stilts to protect itself from climate change