Maarten Gielen is a co-founder of Rotor, the Brussels-based cooperative design practice renowned for its investigations into the material cycles of the built environment. Under his leadership, Rotor has developed a distinctive practice that moves fluidly between architecture, interiors, exhibitions, publications, economic models, and policy proposals, always with a critical eye toward how resources are organized, consumed, and reused.

In 2016, Gielen helped establish Rotor DC, a cooperative dedicated to the large-scale recovery and reuse of construction materials. By dismantling, processing, and trading salvaged components, Rotor DC has become a pioneering force in Europe’s circular economy of building.

Gielen’s work consistently emphasizes generosity toward the city that sustains the practice. In Brussels and beyond, Rotor under his direction collaborates with contractors, nonprofits, and companies to cultivate a regional ecosystem of reuse—reimagining architecture not as a linear act of consumption, but as a circular practice of transformation.