Champigny-sur-Marne, south of Paris, is known as a socially disadvantaged area. Many of its residents are immigrants, and many are unemployed. The town is blanketed with tracts of unattractive pre-fab housing. Now a multi-million euro project is building new single-family houses - and in an especially unusual move, they’re being built directly on top of the prefabricated units. The goal is to create dwellings that will breathe fresh life into the community.