Kevin meets a master craftsman whose dream is to build a castle made entirely of mud. Kevin McCabe is the leading living exponent of the ancient art of cob building - wrestling houses out of mud using his bare hands. But Kevin doesn't just want to build another cob house, he wants to build a cob castle. Not only that, Kevin also wants their gigantic new cob house to meet the highest environmental performance targets ever set. It is truly an almighty challenge. The house will be formed of two vast curved cob roundhouses - the largest of which is inspired by the natural geometry of a snail shell - connected by glazing and topped with undulating wild-flower meadow roofs to mirror the surrounding Devon countryside. But building it involves mixing and laying a mind boggling 2000 tonnes of cob, all during warm sunny weather. Kevin is determined to have the main cob walls up in a few months. But soon the sheer scale of the task becomes clear.

Kevin McCloud follows the progress of 37-year-old Angelo Mastropietro, as he transforms a damp, dark and abandoned cave in Worcestershire. Having recently been diagnosed with multiple sclerosis, Angelo wants to create a retreat to help him cope with the news and become a 21st century caveman. He has a budget of pounds 100,000 and plans to almost single-handedly carve, cut and drill into the hillside to make the cave comfortable for contemporary living. However, there is no manual for a project of this kind, and the unique challenge soon becomes an obsession.

Every Englishman’s home is his castle but for Francis Shaw this is quite literally true. He and his wife, Karen, and their two young daughters, bought the ruins of a 14th Century castle in Yorkshire and took on the remarkable challenge of turning a pile of stones into a beautiful home. Surrounded by rolling green fields, the location is idyllic; however, the castle itself was little more than four crumbling walls.

A young farmer and architect in Northern Ireland hopes to make a home out of four large shipping containers welded together to form a giant cross. Patrick Bradley has come up with a pounds 100k house design to be built out of four 45-foot shipping containers, welded together to form a giant cross and cantilevered over the top of a stream at a beautiful secluded spot on the family farm. His mum is hoping his new home will get Patrick a girlfriend. But his tiny budget is soon under threat.

In 2019, Olaf and Fritha set out to build on a tricky slice of land in West Sussex, boxed in by an A-road and trainline. Kevin McCloud returns to see how their triangular triumph is faring.

Kevin returns to see how Ben Law's woodsman's cottage has changed. The house has bedded down into its landscaped kitchen garden and his life has changed in unexpected ways.

Kelly and Masoko Neville set about building not just a spectacular oak frame and straw bale house, but a whole new way of life in the Cambridgeshire Fens. Kelly is a carpenter by trade and has always dreamed of building an eco friendly home with his own hands. This highly sustainable house, sitting in harmony with nature and its surroundings, will become the base for Kelly and Masoko's new self-sufficient life where they will produce their own food and energy from the land.

Kevin McCloud follows a project to renovate and extend a classic 1920s cinema in Thorne, South Yorkshire. With little knowledge of restoration, Gwyn and Kate boldly set about turning the dilapidated building into a family home using masses of concrete after taking advice from an architect friend. The couple are hoping to create a hydraulic glass wall that opens up one side of the house to form a UV-filtered canopy, and there are also plans for a white roof extension that resembles a diving board.

Jonathan Broom and his wife Deborah have put everything on hold while he pursues his dream of building a mini Hollywood Hills-style mansion right in the gritty heart of north London. For ten years Jonathan Broom has been obsessed with building his own home.They finally stumble across a scrap of land right in the gritty heart of North London, but it's fraught with problems, and the only way they can build their wildly ambitious £1million pound family home, complete with nanny flat and swimming pool, is by sinking half of it six metres below ground. It's a project that pushes the couple and their builder to the very limit. Desperate to make every penny of the budget stretch, Jonathan strikes every deal he can, and even sells his business to raise funds. Originally scheduled to take a year, this giant hole in the ground consumes their money and lives for much longer.

Tamayo Hussey's missed Japan ever since she moved to the UK with her husband Nigel. To stave off the homesickness they've decided to transform a forester's lodge into a Japanese house complete with roof bath, tatami room and sliding paper walls. Keen to keep costs under control, Nigel and Tamayo decide to engage only the design skills of an architect and with no previous building experience they bravely go it alone, working without any detailed drawings and fire-fighting problems every step of the way. The wood they're using for the timber frame - Japanese larch - hasn't been used for building houses before in the UK, so no one can be sure it will be strong enough, the new interior walls don't meet properly and the replacement window design can't cope with the rain. But Nigel and Tamayo are determined to overcome any obstacle to get the Japanese house they're so desperate for.

Confirmed city dwellers Michael and Phil have moved to the country to run a farm, start a micro brewery and create in a vast, dramatic 21st-century farmhouse to live in. Michael Butcher and Phil Palmer were confirmed Londoners, loft-livers in the heart of Soho. Until they fell in love with Christmas Farm, near Newbury, and took the life changing decision to quit their urban media jobs and move to the country. They faced two big problems however: first there was an agricultural tie on the land, so Phil and Michael would have to become farmers; the second problem was the uninspiring faux-alpine timber chalet serving as a farmhouse - it had to go. But Phil and Michael have decided they don't want to build a regular brick farmhouse as a replacement. Determined to bring a bit of urban glamour to their new home, they want a 21st-century farmhouse unlike anything the area has seen before. Phil and Michael's version cleverly combines a vast, white, dramatic open-plan party pad upstairs, with muddy functional farming spaces below. As the builders go to work on the extraordinary hand-crafted flint exterior, complete with the largest sliding trapezoid window in Britain, Phil and Michael must juggle construction with farming the land. And in order to make it all work financially they decide to set up a new micro-brewery in the barn.

Kevin McCloud meets Clinton Dall from Sussex, a self-made businessman and father of four aiming to build one of the largest homes ever featured on the show. Dall wants the end project to be perfect - from the finish of his mirrored cruciform steel columns, to how the floor tiles line up with the dining room table, and is willing to spend whatever it takes to achieve his vision. However, the construction represents a huge risk, as down one road lies abject failure and financial ruin, while down the other, is the creation of something sublime and almost heroic.

Boat enthusiast James Strangeways invites Kevin McCloud to survey progress on the construction of his new home, which his architect nephew Ben Hebblethwaite has designed to be as 'un-houselike' as possible. James has spent the past 35 years travelling the canals and waterways of Britain, and despite never liking houses, has decided now is the time to put down roots on dry land. Ben hoped a home standing on stilts above a marsh, and incorporating ship-like qualities such as a keel-shaped roof, will be enough to satisfy his boat-mad uncle. However, Ben's contractor goes into liquidation a few months into the project, taking pounds 87,000 of the pounds 300,000 budget, and when James decides to make a few tweaks to the design, alarm-bells begin to ring for the young architect.

Kevin McCloud follows the progress of teacher Michele Long and architect Michael Howe, who want to restore and transform a 100-year-old blacksmiths in County Antrim near the coast of Northern Ireland. With virtually no practical experience, Michael wants to do as much of the project as possible by himself. However, the weather on the coastline is fierce, and the freezing weather coupled with a tight budget of 150k means the build is stretched from one to three years.

Kevin McCloud follows the progress of private chef Ed Versluys and pilates instructor Vicky Anderson, who want to convert a concrete cowshed in the Somerset countryside into a three bedroom home. With the help of one young builder and the knowledge they can learn from the internet, the couple plan to project manage the conversion themselves. However, they have only eight months and a budget of just over pounds 200k to make a warm and comfortable home with straw bale walls and wide expanses of glass.

Kevin McCloud follows the progress of Stephen Yeoman and Anita Findlay, who want to build a cutting-edge, post-industrial house covered in rusty metal. However, their prominent riverside plot in the traditional and architecturally conservative area of South Downs means everyone will be watching. The project proves to be a real rollercoaster when the fitting of the rusty steel cladding goes wrong, cash flow problems threaten to bring work to a halt, and the couple announce that a baby is on the way.

Following the work of Ed and Rowena Waghorn as they continue to build a handcrafted, five-bedroom house on an eight acre smallholding in Herefordshire, 10 years in the making. Progress on the build was slow as Ed decided to do most of the work himself, and after four years the house was still a shell. Now, years later, is it possible this house may finally become a medieval masterpiece?

Edward and Hazel plan a shining white art deco lighthouse on a rugged beautiful clifftop. But almost immediately their wildly optimistic plan runs into trouble.

In south Manchester, can Colin and Adele overcome contractor issues, delays and financial ruin to finish the build of their eye-popping curved glass home?

Kate and Rob replace their 1940s past-it prefab with a bespoke, modern, factory-built home using volumetric modular construction. But will it feel like the characterful home they dream of?

Ship’s captain Dorran promised his family he’d build a super-modern underground lair on a hill outside Canterbury. But as the epic build hits choppy waters, will Dorran fulfil their dream?

Zimbabwean born Davi and Matt from Australia set out to build a house in the Chess Valley with a radical multicultural design. Can they deliver, or will it end up just a mishmash of ideas?

Corinne plans to build a beautifully crafted, wedge-shaped home on a slither of garden down the side of the house she’s lived in for 24 years. But it sits in a strict conservation area…

On a nostalgic revisit to the first ever Grand Design, from back in 1999, Kevin finds out if Tim and Jules are still flying high in their timber-framed home on the cliffs above Newhaven

An isolated hilltop in the Brecon Beacons might seem an inhospitable place for a couple's first home. But Adrian and Corinna both grew up in the area, and the ruined farmhouse they chose to restore had been in Adrian's family for generations. The site's lack of mains water and electricity gave them no qualms. True, the track up the hill was often inaccessible in winter. But the landscape was beautiful and they both felt they belonged there