Adam and Tassy take on an abandoned water tower - a concrete column stretching over 20 metres into the Northamptonshire sky - and turn it into a fun family home. Their radical design includes a concrete interior with curved walls, slides, secret rooms, a fireman's pole and - up in the tank itself - a swimming pool and a sky garden. The plan is to sell their terraced house and get a mortgage to raise £400,000 and do most of the conversion work themselves - even though they have two young children already and a third on the way. It's wildly ambitious and gets off to a slow start when a steel reinforced floor takes forever to excavate, and they have to build a sound wall to reduce the hum from a nearby electricity substation. As concrete pours, their walls start to leak and it looks like their water tower doesn't want to be lived in without a concrete-soaked battle of biblical proportions
