The team investigates one of the most genuinely shocking cases ever featured on the programme, meeting a couple whose builders were booked to convert the basement - but instead caused the entire house to collapse to the ground. With the blame so clear, why has the situation proved so difficult to resolve?

Also in this episode, the brand new homes with a catalogue of fundamental errors - including a roof that has already had to be replaced three times. And why choosing a trader from websites apparently listing the best in the business doesn't guarantee you will get the right result.

Presented by Julia Somerville, Angela Rippon and Gloria Hunniford. Show less