A Nottingham couple cement their relationship with an ambitious floating home, while in London George discovers an explosion of global architecture in a tiny one-bedroom flat. In Lincolnshire, family relations are put to the test as two teenage siblings take on the task of building their own mobile homes away from home. Plus, together with master craftsman Will Hardie, George conjures up a magical 30-mile vista in a wall just 20cm thick in their secret garden studio flat.

George and Will Hardie set off on a nautical adventure to build a beach hut that can sleep four people and float. However, they only have six square metres to play with. The pair seek inspiration from a high-end hut in Dorset, an ingenious space-saving houseboat in Germany and a "half house" in London, but their design efforts prove to be anything but plain sailing.