"Yellowred" is a publication that concerns architecture projects, built on preexisting architecture, converting, reusing, extending, downsizing or refurbishing it. Its main goal is to illustrate how buildings, in their inevitable transformation process, can be re-used. This publication collects a number of projects that show a capacity to rediscover in the existing building hidden potentialities, transforming them in opportunities for the reused building. "Yellowred" talks about the strategies, themes, ideas and advantages of extending the lifespan of an existing structure, which has become a widely diffused practice due to today's global commitment for what concerns sustainability. On the other hand "Yellowred" looks at examples from the past, showing that reusing existing buildings has Always been part of architects' concerns, for economic, social or cultural reasons.