After a four year stint living in New Zealand, ex-RAF pilot Jon and GP Gill Flewers want to build a Kiwi-style hill house on the slopes of the Malvern hills in Worcestershire. They plan to build an ambitious three-storey home clad in wood and stone, but the pair encounter problems as the site is so steep builders do not want to take on the job.

Kevin McCloud meets young architect and shed fanatic Micah Jones, who plans to transform an old agricultural building in County Down, Northern Ireland. Micah plans an upside down, four bedroom shed using new techniques and materials, but the £200,000 budget runs short, and Micah is forced to take on some of the building work himself.

Kevin McCloud visits a house belonging to an engineer that resembles a giant snake. The building was inspired by an ammonite shell and has a scaly, curving structure that spirals over two levels and combines natural materials with the latest modern technology. However, completing the project within the 12-month schedule may not be possible.

Design engineer Joe Stuart and service designer Lina Nilsson take on the London property market, as they build their own home on a miniscule 38 square metre plot. Joe designs a split level, six half-floor house that will cleverly maximise the space, but the project is soon runs months behind schedule, and thousands of pounds over their budget.

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?

After 15 years of saving and planning, ecologist Fred and communications manager Saffron Baker start building work on their new family home in a village in the Peak District. However, the couple face difficulties as the start of construction proves more a feat of civil engineering than a house build, and work comes to a halt when their self-build mortgage falls through.

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?

Kevin McCloud meets Chris and Kayo, who plan to build a unique, Roman-inspired home on the protected land surrounding one of Britain's most historic abbeys in Hertfordshire. The pair find themselves constrained by stringent planning conditions, and the intricate and complicated build puts both their schedule and budget under a great deal of pressure.

Kevin McCloud meets neurologists Penny Talelli and Mark Edwards, who plan to combine their love of old and contemporary architecture as they transform a derelict Victorian gatehouse in North London. However, the pair soon find themselves struggling to balance their busy working lives alongside project managing the build.