Spazio collettivo tra città e residenza.

Literature about urban planning debates of two main topics: public space and private space. These subjects are mainly processed as two different and detached objects, no common ground can be found, apart from their boundaries. This clear distinction could be smooth by a specific urban environment: the common space between city and housing. If well designed and balanced, common space is able to satisfy the requests of both citizens and residents. The firsts ask for visibility, vitality and sharing that can be called urban quality. On the other hand the seconds ask for safety and privacy. In this survey we try to elaborate an analytical method to find out some principles for a good design of common space. It begins with the decomposition of the space in its components. Then these parts are reworked on the strength of thematic affinities. Finally we can find three main principles: accessibility, hierarchy and functional mixitè.