At Xella, we have been asking ourselves a fundamental question for years: how can we work as circularly as possible, or how can we ensure that our building materials become new again? How can an old building become a new building? It is always better to make progress with a good partner at your side.
In Belgium, we have therefore been working with our customer Colruyt Group for a long time. Colruyt Group is a Belgian family-owned retailer with a strong commitment to sustainability. Not only do we have a relationship based on trust, but we also share a desire to reduce the use of raw material, lower CO2 emissions and build a circular future. "Colruyt Group has been using Xella Belgium's AAC products for at least 30 years. Several times they have ordered the Hebel panels and Ytong blocks for their stores," says Elly van Overmeire, Innovation Manager at Xella Belgium.
Colruyt Group's vision of sustainability
Our customer Colruyt Group has a clear vision of circularity and how the company treats nature. But also a retailer needs to build their shops from raw materials. The company has set itself a goal: by 2050, Colruyt Group will have a 100% circular approach to construction and building materials under its own management.
A shared vision made the cooperation happen
In 2012, Colruyt Group had redesigned and started renovating its stores to change the way it used energy and materials. Their vision was to stop sending old material to landfill and to reuse everything they could from the old store in the new one. “Previously, old autoclaved aerated concrete got downcycled for an insulating screed or cat litter only. We want to keep its value and recycle it into pure building blocks again and realize a high quality of AAC recycling,” Hilde Carens from Colruyt Group explains. This is possible with the method of selective demolition, where to this end, all parts of the building are being dismantled one by one and we decide what can be reused or what can be recycled and how.
So, three years ago, Xella Belgium, Vito, a flemish research organisation for sustainable development, the recycling depot Chap-yt and Colruyt Group partnered to start a project with our funding suppliers Vlaio & Vlaanderen Circulair. This program focuses on developing circular building practices. "It is not about reusing the products in a down-cycling way, our goal is to find out if you can reuse a block from 30 years ago in another building. This is real urban mining," says Elly van Overmeire.
How urban mining can become a reality
The first practical experiments started back in 2022 with the demolition of a Colruyt supermarket in Deinze and the analysis of the material's powder. The powder of the AAC blocks is now reused in new blocks on a construction site in Temse. In this area, a brand-new Colruyt supermarket is rising on the site of the old store after 37 years. Xella is supplying autoclaved aerated concrete blocks that consist of 100 percent dismantled panels from the old building.