The iconic property show returns for a new run. 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. Howard and Sarah have embarked on a number of ambitious building projects together over the last 30 years, but now they've devised plans for the most radical yet - a sleek, angled, metallic floating home on a tidal estuary near Worthing. Designed to look like a boat, and nestled within an idiosyncratic houseboat community, the structure will sit on an experimental prefabricated polystyrene slab to deal with high tides alternating with hours sitting in the mud. On top of the floating polystyrene will sit a steel frame that will need to be strong enough to resist the stresses of a moving structure, covered in composite insulated steel cladding. Upstairs will be a soaring, open-plan living space with an outer deck and views of the estuary, while below deck there's to be accommodation for them and their teenage children, a home office and a cinema room. It's a huge experiment, with £385k to spend over an 18-month schedule, especially as they'll be doing much of the work themselves and finalising the engineering as they go. Things get off to an agonisingly slow start when it takes months to painstakingly remove a condemned D-Day landing craft from the plot. Designing and making the floating polystyrene slab is a real headscratcher, and they need to buy a crane to get materials over a tall sea defence wall. Add to all that the constant tidal shifts that disrupt any construction and it's a real recipe for disaster... Can they get their grand design over the line?

The new run of the iconic property show continues. 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. Kathryn and her husband Jon lived happily in a four-bed Edwardian home on the same street in north London for 60 years. But now, at 82 and recently widowed, Kathryn faced an all too familiar dilemma: struggle on in a home where getting up the stairs was becoming increasingly difficult, or move away from the street that she's loved for so long. Until she came up with an audacious plan, with the help of her architect, James Mak, to build a new, accessible, ultra-sustainable home right next door, where a garage and extension currently sit. It'll be a mirror image of her current Edwardian house, but with a 21st-century twist. Pulling off this daring feat proves difficult right from the off, when far deeper than anticipated foundations have to be removed to make way for Kathryn's new home. Horrendously wet weather, spiralling costs - including eye-watering fees to connect to basic services - and the worry of selling her old house in time all test Kathryn's nerve as well as her budget. Only time will tell whether this late-in-life gamble will pay off...