Human need is one of the foundations of architecture. Its expression becomes particularly intense when conveyed by the community or in the name of the community, as a collective, shared necessity. Yet we often lose sight of this essential aspect of built environment production processes, focusing instead on matters such as design intentions, formal or technical innovation and authorship. The international conference The Architecture of Need wants to bring together current research efforts to reconsider the role of need in the equation of architectural production by examining how collective-use facilities,devised for community service in response to specific needs, originated and came to fruition in the twentieth century, in any geography. We want to reassess essential need as a key proviso in architecture, and how this determined our existing building stock, at a time when resource scarcity demands that architectural practice and thought contribute towards sustainable, participated built environment management strategies and resist the lure of often questionable building growth trends.