Kevin McCloud returns to Graven Hill in Oxfordshire, the UK's largest mass self-build site, to witness the trials, setbacks and successes of those who are designing and building their own, highly individual homes. First up are Carlos and Maite, who have ambitious plans to build a bold, Spanish-inspired home. But Maite does not just want to live in it, she is also designing it - without any professional qualifications. Meanwhile, co-presenter Natalie Huq follows the birth of a new street in Glasgow, where the local council have given six families an opportunity to construct their own homes on a small plot - beginning with an American-style ranch.

Prabhjot and Shalini's new-build is a super-quick kit house which should go up in a matter of weeks. But with such a close community, their home will need to take their friends' tastes into account as well as their own.

Kevin McCloud follows John and Julia, who are realising their 30-year dream of building an amazing house designed by architect John after years of bad luck. They have secured a plot at Graven Hill in Oxfordshire and John has designed a modernist wedge of a home for them to retire to. But as soon as they start, their run of bad luck continues - the lockdown brings construction to a halt and every month in their expensive rented house eats away at their budget - in turn threatening their vision for a comfortable retirement.

Kevin meets Joanna and Ben, who are channelling all their ingenuity to realise their vision of building an American ranch-style house in a gritty part of Glasgow on a tight budget.