Maarten Gielen is a Belgian designer, researcher and entrepreneur working on material reuse, construction and manufacturing. He initiated the Brussels-based collective Rotor in 2005 and later Rotor Deconstruction, developing practical systems for dismantling buildings and bringing construction materials back into circulation.
With Rotor, he contributed to projects including the Belgian pavilion at the 2010 Venice Architecture Biennale, OMA/Progress at the Barbican, and the 2013 Oslo Architecture Triennale. In 2015, he received the Rotterdam-Maaskant Prize for Young Architects; Rotor received the Schelling Architecture Prize in 2018. He has taught and lectured internationally, including at HEAD Genève, TU Delft and Columbia University’s GSAPP.
Today, Gielen continues this work through Halfwerk, the Brussels-based design and manufacturing studio he founded in 2024, producing lighting, furniture and objects from reclaimed and surplus materials while exploring how circular production can operate at the scale of everyday industrial manufacturing, with an emphasis on durable, repairable, serial production.
Halfwerk is a Brussels-based design and manufacturing studio developing lighting, furniture and objects from reclaimed and surplus sheet steel. Founded in 2024, it uses local, small-scale industrial production as a testing ground for broader systems of material reuse. The studio works directly on sourcing, processing and manufacturing methods that keep steel in use without remelting it. Central to its production is the punching press: a cold transformation process that cuts and forms sheet metal with little material loss, low energy input and versatility across products and batch sizes.
This is combined with bending, rolling, pressing, welding and finishing. Halfwerk develops its own product line while also collaborating with designers and architects, including Nathalie Dewez, Michael Marriott and Denis Romainville. It also restores, adapts and sells second-hand furniture and lighting. Founded by Maarten Gielen, Halfwerk brings experience in reuse, design and material systems into a practical model for circular manufacturing.
