Maarten Gielen is a designer and researcher, and a co-founder of Rotor, a cooperative design practice that investigates the organization of the material environment. The practice develops critical positions on material resources and waste through research and design. Besides projects in architecture and interior design, it produces exhibitions, books, economic models, and policy proposals. In 2016, the practice launched Rotor DC, a cooperative that organizes the reuse of construction materials by dismantling, processing, and trading salvaged building components. Based in Brussels, Rotor aims to collaborate with contractors, non-profits, and other companies to become a central part of a regional ecosystem for large-scale reuse of building materials.