In this paper the notion of trace will be considered as a methodological and epistemological questioning field. Disciplinary working hypotheses in the project field related thereto are aimed at building design tools and forms of representation. The trace is related to insertion and genesis concepts: it establishes relationships with the world and its becoming and it is dependent upon the visual representation system. The trace must necessarily open on elsewhere: to paraphrase Derrida, the time of the trace is the one of deferral. It is therefore a ‘differance’, a necessary spacing, between the origin and the future because it belongs to the past, as it relates to the future. Case study will treat a Turin’s suburb called Mirafiori.