In this book, we review a set of Plan:b projects in Colombia through the environmental, social, and voluntary constraints we faced, and the interim agreements we built around them. We carry out a reconstruction of the central facts behind these buildings through an "inverse" exercise--explaining each project based on contextual constraints and not on singular architectural ideas. We review the work of other authors and the way they understand limitations and difficulties that are part of their creative activity and attempt to generate a broad reflective base to approach our architectural projects and the predominant role that restrictions have played in them.