The UIA (International Union of Architects) has launched an international competition to study new models for social housing. The MCA project, located in Cairo, provides an artificial canal which, connecting the river with the Red Sea and defining a new development corridor, brings water to desert areas. The process may be described as a “positive virus ": the genetic material of the virus consists of a network of channels and an irrigation system. The green areas generated by this process will replace the desert and will host underground activities and utilities. Homes will rise above ground along the canals, in a new urban environment redefined according to the needs of the city.