The aim of this book is to expand the subject and matter of architecture, and to explore their interdependence. There are now many architectures. This book acknowledges architecture far beyond the familiar boundaries of the discipline and reassesses the object at its centre: the building. Architectural matter is not always physical or building fabric. It is whatever architecture is made of, whether words, bricks, blood cells, sounds or pixels. The fifteen chapters are divided into three sections – on buildings, spaces and bodies – which each deal with a particular understanding of architecture and architectural matter.The richness and diversity of subjects and materials discussed in this book locates architecture firmly in the world as a whole, not just the domain of architects. In stating that architecture is far more than the work of architects, this book aims not to deny the importance of architects in the production of architecture but to see their role in more balanced terms and to acknowledge other architectural producers. Architecture can, for example, be found in the incisions of a surgeon, the instructions of a choreographer or the movements of a user. Architecture can be made of anything and by anyone.