George returns for a Christmas special, visiting Christmas-themed builds including a gingerbread house, an underground grotto decorated with over four and a half million shells, and a beach hut advent calendar where every day a festive space opens its doors to the public. George also catches up with expert designer William, to look back on the extraordinary journey to transform his 1970s caravan into a spectacular 21st century holiday retreat.

George visits a canal boat that's been revamped as the ultimate bachelor pad as he prepares to unveil his deluxe family caravan. Having bought a 1970s caravan for just £300, George and his team have spent months turning it into an extraordinary holiday home for him and his family. And George meets a man whose simple plan of converting a shipping container into a garden office proved anything but.

George meets a man who drunkenly bought a 1920s showman's carriage on eBay, but quickly sobered up when he saw the poor condition it was in. He visits a holiday home built from an old World War II vehicle and follows the build of Britain's most landlocked beach hut, based in Birmingham. And George faces a major setback with his own project to create an ultra-modern holiday home out of a 1970s caravan, when he discovers the windows he's ordered are actually meant for a boat.

George meets Ruth Tidd, who is attempting to turn an old caravan that was once used as a home for chickens into an ice cream parlour. He also follows the building of the country's first ever tree tent and is lucky enough to get to try it out, as well as getting the chance to visit some very unique offices built from four old tube carriages. Finally, he travels to Barcelona to take a closer look at the tiny studio flat that thinks it's a five room apartment. And on his own caravan build, George designs a sofa that doubles up as a bath.

George heads to Scotland to meet Julie and George Nicholson, who take an enormous financial risk and commission local designer Sam Booth to build a truly unforgettable, innovative prototype module holiday home. The stakes are high, as the couple have invested their entire savings of £30,000 on a design that's never been tested before. George also takes a trip to Bournemouth and meets Andrew and Emma Collett, who decided not to spend money on a honeymoon but bought a six foot by six foot beach hut to transform into a multi-function small space that can accommodate up to six guests for lunch. Hungry to find inspiration for his own small space caravan design, George visits Gemma Doyle who has lovingly restored some gypsy caravans back to their former glory. And on his own build, George tries to come up with an ingenious solution that will sleep his family of five in a space barely big enough for one double bed.

George continues his exploration of the world of small builds, meeting a man planning a bolt-hole in the Lake District, and visiting a community in Hackney, London, that lives and works in customised shipping containers. He also travels to a home in nearby Shoreditch where the kitchen has been moved onto the roof, and finds out how an Oxford resident has turned his back garden into a party palace using a caravan.

George meets a couple who have invested their savings to convert a wreck of a bus into a holiday let, sees how an old underground toilet has been turned into an apartment and finds how a horsebox has been given a new lease of life as a holiday home. George's own project of making over a dilapidated caravan gets off to a shaky start as his builder fails to see the potential in a hulk of rusting metal from the 1970s.