This article examines the potential to transform urban biowaste into building materials in the Brussels-Capital Region. It connects the growing demand for construction products with the need to valorise locally generated organic residues and reduce dependence on virgin resources.

The study characterises relevant waste streams, transformation pathways and emerging products and situates them within the regional construction sector. It considers material properties alongside availability, processing, regulation and the organisational conditions required to move from experimental products to wider application.

The contribution demonstrates how urban-metabolism analysis can support practical urban mining. It also provides evidence for circular-building research within the Lab and for the wider CARING NATURE programme.