Grand Designs — Season 21

Kevin McCloud follows more of Britain's most ambitious self-building projects, as intrepid individuals attempt to design and construct the home of their dreams. In this first edition, Kevin meets former army captain Justin, who has spent £1.8million on an abandoned neo-Gothic cemetery keeper's lodge and adjoining ex-council toilet block in south-west London. Justin's vision is to restore the lodge but demolish the ugly toilet blocks and replace them with an enormous luxury ground-floor extension, with an added moat and a giant basement with a swimming pool - all just metres from the nearest grave.

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 modeled 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?

Kevin McCloud follows an ambitious build in Cornwall, as Leigh and Richard transform a derelict 17th century flour mill into a contemporary, three-bedroom home. They employ traditional craftsmen to start work on restoring the exterior, but it's not long before the true scale of the damage to the structure is revealed, and as the costs rise, they are forced to take more of the work themselves.

Kevin McCloud revisits professional deep-sea diver Adrian Corrigall and his wife Megan, who planned to build their new family home in rural East Sussex almost entirely out of concrete, with construction involving cutting-edge technologies conceived in Switzerland and never used to build a house before. With both the schedule and the budget under strain, Adrian was forced to resume work as a North Sea diver, leaving Megan juggling this messy and challenging build, all the while looking after three young children. By 2018, water leaks were still to be addressed, the majority of the spaces were raw and unfinished, and the family were still a long way away from moving into their concrete dream. Two and a half years later, with the house now fully complete, Kevin returns to see what living in a cutting-edge concrete bunker is really like.