The architecture and urbanism of the ephemeral as a new symbolic and sustainable urbanity?[L'architecture et l'urbanisme de l'éphémère comme nouvelle urbanité symbolique et durable ?]

At the start of the twenty-first century, the architecture and town planning of the ephemeral are establishing themselves in major global metropolises as an instrument for creating a new urbanity within the framework of a system of symbolic representations of the city. said to be sustainable by the ephemeral performance of architecture. Through the recent Universal and International Exhibitions of Zaragoza 2008, Barcelona and its Forum of Cultures 2004 and Shanghai 2010, we ask ourselves what are the lasting effects of these ephemeral events through the creation of architectural icons in direct connection with the provision of leisure and congress infrastructure. In addition, what are the forces present through the actors and the risks of the project while taking into account the long-term consequences of holding very large events in the urban world? Marketing and urban communication are also mobilized in this book chapter.