This book focuses on the city of Barcelona, specifically in regards to its grid-style design. The author proposes a number of original interventions that implicate this grid in productive ways. By emphasising the value of open forms for city design, they insist that the grid has the unique capacity to channel urban transformation both flexibly and productively, Barcelona Collage explores the potential of the grid as a design tool in both historical and projective terms, analysing its effect on urban processes.