While the concept of "type" has been present in architectural discourse since its formal introduction at the end of the eighteenth century, its role in the development of architectural projects has not been comprehensively analyzed. This book proposes a reassessment of architectural type throughout history and its impact on the development of architectural theory and practice. Beginning with Laugier's 1753 Essay on Architecture, Unexpected Affinities: The History of Type in the Architectural Project from Laugier to Duchamp traces type through nineteenth- and twentiethth-century architectural movements and thoeries, culminating in a discussion of the affinities between architectural type and Duchamp's concept of the readymade. Includes over sixty black and white images.