The research study Space in Motion refers to the crowd and the space created through its action. More specifically, we point out how the crowd is specified and how, on its turn, it can specify the location of its residence. In the first part, an analysis is conducted regarding the body of the city and the way in which it is inhabited by modern people. After that, there follows a distinction of the urban habitation of the masses of people between population and crowd. Then, the crowd is divided into two categories referring to the way people inhibit a city, which are the category of the mimic crowd arising from the bodies of inhabitants-users and the category of the theatrical crowd which is based on human creators. In the second part of this research study reference is made to Volos analysing the main points of the existence of population and crowd in the specific city. The research focuses on the location of the Polytechnic Schools and, more specifically, of the premises of the School of Architecture. Through specific examples of action from theatre crowds it becomes clear how the crowd can alter the function of a specific space far and beyond the floor plans.