Two families hope to save cash and supersize their homes. In Ascot, the Ioannidis family want to create a multigenerational home by doubling their 50s semi-detached house. Daughter Helena and her fiancé Andy are paying the mortgage and parents Paris and Zanette are funding the build from their life savings. Sparks fly from the start between daughter Helena and father Paris, who also project manages the build. In Maidstone, Ben and Eloise Barratt want to double the living space in their cramped 1960s detached home. As well as having a new baby on the way, web-business owner and salesman Ben is piling on the pressure by project managing the build himself.