Grand Designs

Kevin McCloud follows more ambitious self-building projects, beginning with Bryony and Matt, who have spent five years planning the perfect Cornish family beach house, complete with its own surfboard room. But with the project up and running, they have only given themselves a year to finish, despite aiming for passive house standards and with construction of the irregular frame to be done almost entirely on site and by hand - not to mention their busy home and work lives.

Kevin McCloud follows architect Peter and his TV producer wife Emily as they take on the challenge of building twin conjoined houses in London - the plan being to sell one of them to fund the one they will eventually live in. They already have business partners - and potential new neighbours - who have bought into the scheme. Now all they need to do is build the houses. But from the start they are dogged by financial issues - not to mention problems with the experimental nature of the design. Can the two couples retain their friendship?

Thirty-two-year-old London architect Seb has the rare opportunity to build his own house in his grandparents' back garden. His ambitious design challenges many of the conventions of traditional construction, from an innovative roof cladding system he devised himself to a structure made from cross-laminated timber panels imported from Austria. For Seb, this is a chance to create something genuinely original, but it's also a huge personal gamble. He wants the house to be built quickly and to the highest possible standards, on a budget of £420,000. On an awkward, tightly constrained site, every penny and every inch of space have to work hard.

Kevin McCloud meets artists Jana and Rory, who live in a former driving test centre in the east of Edinburgh but have ambitions for something bigger and much warmer to live in every winter. They want to replace the current building with a sleek, contemporary slipped box house with upside-down living to capture a view of the sea - and all on a minimal budget.

Kevin McCloud revisits couple Chris and Gill, who he last met in 2001 when they were renovating a disused textile mill near Huddersfield, West Yorkshire, into modern hi-tech accommodation with a minimalist interior. The presenter finds out how life has been in the house over the past 25 years, asking whether their meticulous approach has stood the test of time.