Ten years in the making, this is the longest running Grand Designs ever. In 2007, Ed and Rowena Waghorn started to build a handcrafted five bedroom house on an eight acre smallholding in Herefordshire. Their budget was just £100k. Made from individually carved wooden beams and walls of straw and clay, the heart of the house was to be a huge medieval style hall, complete with massive stone fireplace and a glorious cathedral-like window with panoramic views across the valley. Ed decided to do most of the work himself. Progress was slow. Four years in, the house was still a shell. In 2012 Kevin McCloud decided to follow the build for another five years. In the end, it's just possible this house might turn out to be a masterpiece.

Joe and Lina's clever space-saving low-budget build may be the smallest two-bedroom house you're allowed to build in London, but it'll be stylish, and theirs - not a landlord's.

Fred and Saffron build a home in the Peak District on a 30 degree slope, with the top floor in plain sight and two post-industrial style floors buried into the thick limestone below

This is one of the most ambitious homes ever seen on Grand Designs - a scaly, curving house that's reminiscent of a giant coiled snake. Stephen Tetlow is head of the Institution of Mechanical Engineers. Stephen's wife Elizabeth is a committed horticulturalist. Together they want to build a home that reflects their passions - one that pushes Stephen's engineering skills to the limit and embraces Elizabeth's deep affinity with nature. Taking inspiration from an ammonite shell found on their land in the beautiful Blackdown Hills in Devon, the house spirals onto the landscape over two levels and mixes natural materials with cutting edge technology. Construction of such a complex curving structure proves a huge challenge and progress is tortuously slow.

Beth and Andrew rescue a crumbling Victorian dairy, hoping to make it into a 'shabby chic' family home fit for modern life. But is the building simply too derelict?

Chris and Kayo build an intricate, radical and complicated home on protected land close to one of Britain's most historic abbeys.

We are a nation that loves our sheds - but not many of us would want to actually live in one. In Northern Ireland, young architect and shed fanatic Micah Jones has the chance to re-invent a dilapidated old agricultural building in the rolling countryside of County Down. Micah plans an upside down four bedroom shed using new techniques and materials. Micah and family move into a caravan on their windswept site for the duration of the build. But their limited £200k budget runs short and Micah is forced to do more and more of the work himself. And then news of a new baby on the way adds yet more pressure.

Penny Talelli has a passion for cutting-edge contemporary architecture, while husband Mark Edwards loves period buildings. Somehow, these two neurologists want to build a family home that satisfies both their tastes. But will it be the best of both worlds or just an appalling mishmash? Taking the plunge, they buy a derelict Victorian gatehouse on a very steep hill in north London, that currently sits abandoned and unloved. The plan is to restore it, paint it white, and then add a giant black zinc-clad box at the back, marrying their love of old and new. But they run into problems. The gatehouse needs knocking down. Excavating the sloping site takes longer than expected. Increasingly struggling to balance their busy working lives with project managing the build, the future of Penny and Mark's unconventional home hangs in the balance.

Few people would be brave or foolish enough to buy a building plot without visiting it first. But that's exactly what ex-RAF pilot Jon and GP Gill Flewers did. Returning to the UK after a four year stint in New Zealand, this intrepid pair want to build a Kiwi-style hill house on the slopes of the Malvern hills in Worcestershire. Their ambitious three storey upside-down home will be clad in wood and stone, clinging to the hill and designed to take advantage of and enhance the surrounding scenery. But there are problems. The site is so steep that builders don't want the job. So, despite a complete lack of experience, Jon quits his job to run the project himself. It proves an emotional rollercoaster ride.