Circular Material Systems: anticipating whole-system design in architecture and construction

The construction sector is one of the most resource intense and environmentally damaging industries in the world. A promising approach to counteract this is to use principles of the Circular Economy (input reduction, reuse, and recycling) to ensure the continuity of value of a building's materials. Thus, we translated the learnings of an in-depth case study analysis including four buildings and their construction processes into a definition and framework for circular construction. We conceptualise buildings as circular systems that produce reusable components or biodegradable materials by practices operating across a building's lifecycle. These practices do not only include material and design aspects to close biological and technological loops, but also immaterial practices such as knowledge and expertise, locality, management and skills, and information. We argue that these organisational aspects that go beyond the current state of the art are critical enablers for circularity in construction. This perspective is relevant for practitioners in the field and allows for a new and holistic look at buildings as 'waste generators' or, in a positive scenario, as 'material depots'. Designing for recycling and reuse will require architects to build collaborations and knowledge across and beyond material value chains.