The Materialenbank is a materials bank established in Leuven, Belgium, in 2020. The goal of this initiative is to promote the reuse of construction materials and support the local circular economy through a collaborative effort involving three local stakeholders: Leuven City Council, Atelier Circuler, and Wonen en Werken (WenW).

The challenge and proposed solution
Leuven’s Circular Economy Strategy is a key component of the city’s plan to achieve climate neutrality. It is based on five pillars, including circular construction. The construction industry is responsible for a substantial portion of material extraction and waste generation in the EU. The Materialenbank seeks to enable circularity by promoting the reuse and recycling of construction materials within a local context, thereby reducing waste and minimising the environmental footprint of construction activities.

As indicated by a report published by the European Commission in 2014, the project was outsourced by Leuven City Council to Atelier Circuler, a nonprofit organisation that offers access to woodworking and metalworking machines. Atelier Circuler partnered with WenW, a social economy organisation focused on reducing local unemployment among disadvantaged citizens. As explained by an interviewed public officer working for Leuven City Council, the City provided spaces to host the activities of Materialenbank, partially subsidised their operations, and facilitated partnerships with other public sector stakeholders. The cooperation of these local entities led to the establishment of the Materialenbank.

The Materialenbank's business model is based on three main activities:
1.    Urban mining: Recovering waste materials from buildings owned by public entities, such as the Leuven City Council, as well as from the local hospital and university. 
2.    Processing: Transporting the collected material to the carprentry workshop to, for instance, standardise the length of specific wood panels and other materials.
3.    Sales: The materials recovered are sold in their shop, both in-person and online.

All three organisations contribute to implementing Meterialenbank’s business model. The team at Atelier Circuler handles logistical arrangements for urban-mining activities and manages sales. WenW’s workers conduct urban mining activities, assist in re-processing materials, and ensure deliveries to clients. Additionally, Leuven’s City Council has appointed a representative to sit on the Board of Directors of Atelier Circuler to participate in the project's management.

Materialenbank’s operations are set in a context of proximity, as they are primarily focused within the Leuven area. The initiative has set an operating radius of 50 km to provide services while maintaining their carbon offsetting efforts. The Materialenbank operates based on local demand for construction materials, responding to the needs of the final users, who are mainly citizens.

Impacts and lessons learned
The collaboration with the social economy organisation WenW boosts local employment and supports vulnerable individuals. The positive and supportive environment of the Materialenbank and Atelier Circuler helps workers from disadvantaged backgrounds, many of whom grew up in poverty and have never had a steady job. The project also fosters a sense of purpose and passion for sustainability and recycling among the workers, contributing to their personal and professional development. By creating local employment opportunities and providing training and support to vulnerable individuals, the Materialenbank improves the liveability of Leuven and promotes social inclusion.

While the Materialenbank’s operations reflect a well-functioning business model, ensuring the project's economic sustainability, the public sector's role remains vital in incentivising economic operators to explore new, currently unprofitable material streams, such as plastics.

Conclusions
Materialenbank enhances local sustainability and resilience, promoting community engagement in circular practices. This best practice shows how a well-structured collaboration between the social and proximity economy can meet local construction material demands, provide jobs for disadvantaged individuals, and support city-wide climate neutrality goals.