Kevin McCloud returns with more ambitious self-builds. In south west London, Justin's restoring a neo-Gothic cemetery lodge and converting its toilet into an extension with a moat and pool.

Greg and Georgie plan to convert a cavernous, dilapidated, 35-year-old barn in Georgie's parents' garden in Kent into a peaceful safe haven. But budget-squeezing building work soon sets in.

Nathan and Amye are building a cathedral-like home modelled on local Dutch barn houses with a sleek twist and a 5000-tile armadillo roof. But the pressure mounts for project manager Nathan.

Energy conservationist Andrew plans to build a radical, self-heating home by storing the warmth of the summer sun into insulated earth banks. But will this gigantic thermal experiment work?

Leigh and Richard plan to transform a derelict 17th-century flour mill, full of rotten timbers and riddled with structural cracks, into a warm, contemporary, four-floor, three-bed home.

Kevin McCloud revisits Adrian and Megan, whose dream home in East Sussex became a nightmare. With the house now fully complete, what is living in a cutting-edge concrete bunker really like?