The book 'Architectural Affordances – Typologies of Umbau' is the result of perennial research and teaching by Andreas Lechner and Gennaro Postiglione at Politecnico di Milano. Edited in collaboration with Francesca Serrazanetti and Maike Gold, it investigates 30 international Umbau projects—architectural transformations—through three temporal scales: those spanning centuries, those exceeding a hundred years, and those occurring within a single century. Each project's material and functional transformation history is illustrated with one plan, section, and elevation, alongside yellow-red diagrams that trace the stages of change.

The projects featured in the book were selected through an international call for papers, with a scientific committee curating the most thought-provoking and exemplary submissions. Central to the book is the exploration of the dynamic interplay between enduring structural elements and temporary components, illustrating architecture's ability to adapt to shifting societal and temporal demands. Traditional buildings demonstrate their versatility through established typologies, enabling diverse and enduring uses over time. In contrast, contemporary construction—often characterized by the separation of structural frameworks and building envelopes—introduces new complexities that call for inventive, autonomous, and adaptive design strategies.

At the core of the book are architectural drawings, which function not only as records of transformation but also as essential generative tools within the discipline, bridging historical precedents with future architectural paradigms. By uncovering the affordances embedded within built forms, the book develops a contemporary, "drawn" theory of transformation, offering nuanced perspectives on some of the most pressing issues in architectural practice today. Supplemented with essays and Hermann Czech’s seminal 1997 text 'Umbau', this book is an essential resource for architects, scholars, and students. It encourages rethinking adaptation and reuse as vital strategies within contemporary architectural practice.