Based on research work on a new establishment area near Bologna, the present paper shall deal with a common dream of architects, urbanists and their customers: their shared idea of the perfect city which can be thoroughly planned, their utopia of the new city as it can be observed in the Disney Celebration and in every CID. These realities do not differ much from the urban way of life described by L. Wirth: it is right there that homogeneity and differentiation coexist and become one, thus producing the very distinguishing factor of urbanism as a way of life. Generally speaking, in many periurban areas as well as in the CIDs and in the Gated Communities, there is an attempt to reproduce all the positive aspects of urbanism, while trying to avoid, or at least hide, all the difficulties and negative sides it entails. As Guidicini has long suggested, this approach reaches its highest peak in the rationalism of Le Corbusier. It is therefore possible to see a connecting line along the main stream of rationalism, which affected New Towns and Garden Towns in the past, as well as it nowadays affects the Common Interest Developments, of which the one examined is one significant example.