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Sustainability In search of urban building gold
Reusing materials is a mindset
Urban mining is part of our overall vision on sustainability and innovation. We are already integrating as many circular materials as possible into our construction projects.
In search of urban building gold
In Flanders alone, the building sector produces 15 million tons of construction and demolition waste per year.
This is a sizeable amount, especially when you consider that it’s the equivalent of about 40 demolished Empire State Buildings. This gigantic mountain of waste is a potential gold mine of reusable raw materials and materials. It is therefore no surprise that more and more architects, engineers, entrepreneurs, and project developers are showing an interest in urban mining. Urban mining means extracting raw materials and materials from construction and demolition waste in cities, and using them for the construction of new projects. This may involve di erent types of materials such as electronics, wood or metal, but also soil that is dug up for new projects. In Brussels alone, 2 million tons of soil are excavated each year. We can transform this soil into clay plaster to finish walls, or cob to make floors and non-loadbearing inner walls. Such materials are nothing new, as we built with them in the past, but at some point, we stopped using them. Yet they are very useful: the soil is pressed and not baked, so we don’t need fossil fuels to transform the raw material. This makes them doubly sustainable!
— Price tag Part of the reason why many companies are not yet fully on board with this circular mindset is due to the price. New building materials
Urban mining
For our Burenberg project in Leuven, we worked together with Atelier Circuler vzw. This Leuven-based association recovers reusable materials from urban buildings as part of its Urban Mining project. It dismantles and extracts these materials before the buildings are demolished or renovated. The mined materials are then sold via “Leuven's Material Database” (“Materialenbank Leuven”), or are reused in other projects.
You can learn to recycle
We regard old buildings as a source of new raw materials. This is not easy, but it’s a challenge we are increasingly taking on.
are produced in large quantities and are therefore cheaper – but this is slowly changing. The raw materials required to make these materials are becoming increasingly expensive, which means that recuperated materials are coming more and more into the picture. That's a positive development! It’s particularly good for our economy to recover and repurpose local materials. At the moment, materials are often obtained from distant countries such as China or India, which is of very little use to our economy. In addition, it requires unnecessary transport, and waste is produced that we also have to dispose of somewhere else.
— Obstacle Making a new high-quality material with a residual product is a challenge. There are already companies that are looking into how to produce high-quality concrete from concrete debris. But for this, certificates are required, which are not easy to obtain with recycled material, since the origin is not always clear. Also, the volume we reuse is often not in line with what we need for a new project. Small scale is still an obstacle today, but that will definitely change. More and more people are gaining knowledge on this topic, and gradually companies are working along the same lines, which will ultimately lead to successful partnerships.
— Legislative context The role local, regional and national governments have to play should not be underestimated here. About 15% of the market consists of public tenders, which is a considerable percentage. Consequently, government bodies can have a significant influence on the real estate world and give a push in the right direction. Fortunately, there are already initiatives from various public authorities. The
'Urban mining is already taking place locally today, which is a good start.
Brussels-Capital Region, for example, is a pioneer. It has followed a whole process from awareness to experimentation, and is now gradually coming up with a legislative framework in which it is no longer possible to simply demolish buildings. In Bruges, too, certain materials are no longer allowed because they are di cult to recycle or reuse. So things are certainly already happening locally, which is a good start. As an entrepreneur, it’s important to jump on board now – to think about the next steps, and to work on sustainable projects on a smaller scale.
— Toward the future We are optimistic about the future, and hope that a number of measures will be taken in the next decade to make the process of urban mining easier, both in terms of the extraction of raw materials, and the e ective reuse of materials in new construction projects. The current CO2 impact of the construction sector obliges us to do this, and the development of urban mining will help us to achieve the climate targets more easily. What is an exception today can become the norm within 10 years.
