Is Density in isolation the Ideal ?

actes numériques, DVDInternational audience"Beyond which dimension is the city threatened in its shape as well as in its functioning, even, in its definition, its identity as city?" questioned Hubert Damisch in its article Fenêtre sur rue (1994). The developments of the contemporary urban territories imply to consider again most of the concepts that are usually used to think and plan the hyperville (A. Corboz) and its more recent developments - as centrality, periphery. They also invite us to lead further thought on some fundamental notions often mobilized to think the city of the 21st Century - as the ones of density (which has to be defined), or nature (being now, very often, a kind of "green alibi"). For which kind of idea of the city? "Is Density in isolation the ideal solution?" (R. Koolhaas) The city - which has most often performed as the privileged "condenser" of the products of modernity - is no longer alone in terms of facing these upheavals that result in the questioning of its definition as well as its image, and thus its representation. The countryside itself, and nature have also undergone transformations, turning their very concept into a subject as well. The antagonism between city and nature, which was for a long time a founding concept in many architectural cultures, and that "paralysed the territory for so long" (A. Corboz) is no longer operating today for the hyperville - although some insist on casting a nostalgic eye on our contemporary "hybrid" spaces