Ian and Sophie Cooper met at university and have since spent their time together enjoying life in London. Ian works as a marketing consultant in telecoms and Sophie is a sales manager for a fashion firm. Both are passionate about design. They’ve done the usual thing of renovating flats and moving on... but three years ago they realised they wanted a different kind of life in a different kind of building.

Inspired by an illustration on a yoghurt pot, Chris Ostwald decides to build a New England-style water mill in the Chilterns, on a hill and nowhere near any water.

Sarah and Dean Berry grew up on a council estate in Newport. Having moved away to London and made good, they have now returned home 17 years later and bought an 18th century folly - a castle perched on a hilltop. They not only plan to restore the folly to its former glory, but wrap a large modern extension around the original structure, with lots of glass to capitalise on the amazing views.

Kevin McCloud follows the progress of architect Richard Hawkes and wife Sophie, who are moving from London to the Kent countryside to build a hi-tech eco-friendly house with room to grow their own food. Richard also wants their new home to blend effortlessly into the surrounding countryside, concealed beneath a huge arch of clay tiles covered with earth and planted with grass

Daren Howarth and Adi Nortje are keen to build an earth-sheltered home from recycled materials in Brittany. The house is a very low tech one, mainly constructed from old car tyres.

Dairy farmer Andrew Ainslie and his artist wife Meryl, who run a gallery on their farm, build a modern barn-style farmhouse on their 700 acre farm in the rolling chalk hills of Wiltshire.

Mimi De Costa and her husband Andre, a doctor, had spent years looking for a plot of land when they came across a bungalow in Kent. The original bungalow They bought it for the site - 12 acres of organic pasture and woodland - and started to plan a new home for their sons, Sean and Tye, that would suit a lower impact way of living. But what they're building isn’t going to be a reproduction of the bungalow. It's a squarish, modular building, with glass walls from floor to ceiling. The outside of the building is clad in cedar that will go grey to match the surrounding oak trees. The idea is that by prefabricating most of the house it should be quicker and easier to put together on site. But although it will be precision made, it isn’t a kit house.

Not everyone gets to live out their childhood dreams, but in 2004 Francis Shaw did exactly that when he bought a crumbling castle on English Heritage’s Buildings at Risk register, to restore. Little did he know what he was letting himself and his family in for by taking on this project. Set in the heart of the Yorkshire Dales, the peel tower dates back to the 15th century and was protected as a Scheduled Ancient Monument. It took months of red tape wrangling before Francis finally got permission to start working on the building, but with the rubble barely cleared, one of the enormous 700-year-old walls collapsed showing just how much of a labour of love this project was going to be. Two and a half years after Francis and his wife Karen moved in, Kevin McCloud returns to find out that the spiralling costs of restoring the castle has meant the fairytale life is nothing like Francis’s dream.

Kevin returns to visit Kelly and Masoko Neville who 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.

Barry Surtees wants to build a modern mansion for his family in Brighton, but he is soon battling with escalating material costs, complaining neighbours and finally a heart attack.

Eight years ago Alex and Cheryl Reay left London for a new life in the New Forest. They bought a run down medieval thatched cottage and lovingly brought it back to life. Then just before Christmas, with Cheryl pregnant, disaster struck.

Jim Fairfull considers himself a very lucky guy. He was out fishing with a friend when he came across a beautiful, secluded loch. It's a magical place with stunning views over the nearby hills. He got chatting to the farmer who owned it and discovered the

Kevin returns again to see how Ben Law's woodsman's cottage has changed.