Materiality is a central and ongoing theme in architecture. This book explains how materials become fabrics of our culture. Metabolism traces the metamorphoses between nature and technology, science and sensuality. The concept of metabolism was elevated by Gottfried Semper (1803-1879) to a fundamental element of his theory. He referred to the phenomenon where structural forms, originally linked to the processing technique of a material, are relieved of their constructive function and transferred as ornaments into other materials. The topic is presented for the first time from a historical perspective, reflecting current transdisciplinary insights. Examples from Aalto to Zumthor illustrate the aspects of past and present material concepts.