Between the 1950s and 1990s, the material known as Reinforced Autoclaved Aerated Concrete (RAAC) was used mostly in flat roofing, but also in floors and walls.

It offered a cheaper alternative to standard concrete, but the discovery of its short lifespan has meant serious problems. It made the headlines when it was found in schools and hospitals, but it has been used in housing as well.

Thousands of homeowners have been told their properties are no longer safe because of RAAC. Some are living on ghost estates under threat of demolition. Others have even been forcibly removed. Local authorities are offering a percentage of the market value before the faults were identified, but homeowners say this will leave them homeless and in debt, paying mortgages on rubble.

Listen to the programme here.