"Sketch represents the starting point of the design process and becomes an essential element of the method. Someone could notice parallels between architectural design and Derrida's "blind spot"; the blind spill that Derrida tries to locate determines the entire text as proposals that have been written either subconsciously or with no thought. Furthermore, sketch is free of material commitments and spatial effects, occurs as a result of short, explosive moments and becomes the key to the whole building."
Coop Himmelb(l)au in "Transforming the Urban Landscape  Architectural Studies and Projects of Organisation for the Cultural Capital of Europe Thessaloniki 1997"