Architect George Clarke delves into the world of small builds, meeting people taking tiny, unpromising spaces and creating innovative and exciting places to live, work and play. In the fourth episode of this ninth season, George is amazed by a couple's plan to turn a coach into a mobile home, complete with a garage for their treasured Mini. He also meets a pilot who has created a garden den from a small plane. Elsewhere, George's observatory build takes him to one of the world's largest telescopes.

Architect George Clarke delves into the world of ingenious small builds, meeting people creating places to live, work and play in the most unlikely of places. Here he meets a couple who turned an old fire engine into a bar to raise money for firefighters' charities and a 23-year-old who built a shepherd's hut from scratch, including the nuts and bolts. George also visits an extraordinary home in Chile and Will Hardie builds a telescope.