Development of a Cohousing project - am example from Italy

What is Cohousing? How Passive Houses work? And how can the combination of these two "concepts", deals with Green Energy? According to last studies, the most effective way to improve the ratio between energy supply and demand is to act on social behaviour, in order to reduce the energy consumption. Is it possible for families used to live in big cities? This scientific work will provide answers to the previous questions and it shows how economically feasible is a similar project, when social behaviour meets innovative engineering systems.