Howard and Sarah build a radical metallic floating home designed to look like a boat, nestled within an idiosyncratic houseboat community on a tidal estuary near Worthing. But will it sink or swim?

Sarah and Pip are smitten with a 150-year-old Bedfordshire barn that's keeling over. Can they retain its charm and spirit, while at the same time transform it into a sleek, modern home?

Recently widowed 82-year-old Kathryn plans to build a new, accessible, ultra-sustainable home right next door to the home she lived in with her husband Jon, where a garage and extension currently sit. It'll be a mirror image of her current Edwardian house, but with a 21st-century twist.

Kevin revisits Graeme and Melanie, whose hugely ambitious Hackney haven was hampered by a basement bombshell. Have they finally got out of the red and into their modernist home?

Does good architecture have the power to heal? Kevin revisits Elinor and Born, who in 2017 built a clean-aired, hypoallergenic house, motivated by the extreme allergies of their two boys.