Grand Designs - Season 12 (2012)

A couple buy, then demolish, an old boathouse on the Thames with plans to build a modern home which will clash with the traditional surrounding homes, alienating their neighbors.

Two men buy a derelict Victorian water tower and convert it into a luxurious home for themselves, topped by a magnificent sitting room with 360 degree views of London from the tower's former metal water tank.

A couple buys a ground floor studio and an extensive underground warren of rooms with plans to make it a sumptuous home. While the husband works to pay for it, his interior decorator wife manages the project to turn crumbling squash courts, underground pools and falling-down corridors into a below-ground home.

Instead of the normal white stone cottages of this area, a couple build a wooden clad house with a grass roof and outbuildings that blend in with the landscape.

Film props buyer Tracy Fox and scenic artist husband Steve want to build an "urban shed" out of corrugated cement fiber board and twenty foot panels of polycarbonate sheeting.

The presenter revisits the 1970s converted bungalow on the Isle of Wight where Lincoln Miles and his wife wished to use unique materials to the build which includes a 3 story tower that reaches the treetops.

Kevin catches up with Claire Farrow and Ian Hogarth who began a wild journey in 2010 to create d the ultimate fun family home, right in the heart of London, including a dance floor, dj booth and sauna.

Braintree (revisited) . Freddie Robins and Ben Coode-Adams leave their cramped London flat to take on the conversion of a 500 year old timber framed barn in Essex where they plan to live and each have an artist's work studio in this 7000 sq ft space. They have a daughter called Willa.

The Hedgehog Self Build Co-op consists of Ten couples /17 adults who build ten homes as a co-operative, they each commit to build for 30 hours each per week for two years, None of them have any experience in building, and they are living in mobile homes temporarily. The Co-op is situated just outside of Brighton in East Sussex on the south coast of England. The houses are all bungalow style and detached. In 1999 the build cost of each was £60,000 each, plus the land cost. They were built through 1998.