Geri and her husband Kevin bought an 18th-century property in Devon after falling for its gothic arches, quirky architectural features and a glass lantern-like cupola, but discovered it was in a critical condition. The expected budget for repairs quickly doubles and Geri has to take over management of the build herself - but then the true impact of trying to undo more than 200 years of amateur construction hits home.

A last remnant of a once grand and wealthy estate, St Peter's Barn had been overlooked for generations and carved up by modern farming practices. The moment Graham and Nicola walked into it, they knew it was the family home they had been searching for. At 35 meters long and 20 meters high, the crumbing cathedral-like interior would appear an impossible dream to most, but roofer and builder Graham saw its potential and decided to pour their life savings into buying it.

Simon Kelsey had known and loved one particular house on Coltman Street in Hull since he was ten years old. The once grand Victorian townhouse was already in decline but now it's in critical condition - ignored for years, carved up by modern conversions and on one of the most deprived streets in the town. Simon took a massive gamble and decided to try to save it.

Six centuries of history drew Kate Armstrong to Cassillis House in Ayrshire. Originally from Australia, Kate has always had the dream of owning a castle and she picked one that was in a desperate condition. A four-year struggle began to restore 110 rooms - but not only was Kate attempting to save the fabric of the building, she took on the responsibility of preserving the story of the Kennedy Clan who called Cassillis their home for 21 generations. While the new owner discovers waterlogged kitchens and hidden rooms, the historical investigation reveals the building's transition from defensive fort to pleasure palace.

Hayley and Alan are not your typical restoration heroes. Struggling to find a decent sized family home, they decided to put in a bid for a Victorian chapel in the Welsh valleys. It was derelict and in need of a saviour - they bought the lot for just £25,000. With only £20,000 of their own money left to restore it, they begin a struggle of almost impossible scale. They start in the vestry to the rear, which they hope to transform into a spacious three double bedroom modern home. The plan was to then get a mortgage to complete the whole chapel, but the enormity of the task and the consequence of their tiny budget soon hits home. Simply digging foundations is a gruelling task as, rather than hiring a digger, they opt for doing it by hand to save their tiny budget. As Alun and Hayley struggle to save the centre-piece to the village, the historical investigation gains pace.

Charlotte and Helen have purchased Pitkennedy School in Angus which was once the cornerstone of a community until it closed in 2006. They hope to create a beautiful home from a neglected old Victorian school.

Little Naish sits in the corner of a six acre Victorian walled garden and looks like a gothic tower directly from the pages of a fairy tale, but it's currently heading towards a tragic ending. Peter and Anne Hills have deiced to sink their life savings into trying to save it.

Caroline meets with Alex and her partner Martin who have purchased Rock Farm, which was once a perfectly proportioned Georgian house but is now a crumbling shell, cracked and contorted out of symmetry.