How did you bring this circular and community-driven approach to a Belgian context? Belgium is known for its bricks, so we decided to make one ourselves from local clay. We applied them to a project, the ‘Bioclass’, a small classroom in the town of Edegem. We made the bricks by hand with the help of volunteers, schools, and youth groups. It turned into a kind of festival where everyone made their own brick, and it worked incredibly well.

After developing the Bioclass, more and more people started asking if they could use these bricks. That’s when we realised there could be an economic model behind it. It led to the creation of BC materials, which focuses on earth-based building solutions, including compressed earth bricks, clay plasters, earth floors, and even natural paints that can be used indoors. We also initiated BC studies, that provides research, training and workshops around bioregional materials and techniques.

What started as an experiment has grown into a major initiative, proving that locally sourced materials can be both viable and scalable. It has led to surprising collaborations and results. For Atelier LUMA in Arles, a material research centre, BC materials developed materials using elements found in the surrounding Camargue region. Working together with Assemble, a London based architecture firm, and the specialists of LUMA itself, they developed compressed earth blocks and earth mortar using local waste from a quarry, and an acoustical earth plaster which contained the chopped stem and pith of sunflower waste. Closer to home, the office sourced wood from the Sonian Forest in Brussels, preventing the valuable wood from being sold abroad. Since the forest and trees already belonged to the municipality – the project’s client – it reduced the project’s material costs. What’s even more remarkable is that the wood is harvested traditionally, using horses to fell the trees and transport the logs.

You can spot a preference for traditional techniques and craftsmanship in your projects. Why is that so? We always try to combine local material and local craftsmanship. To us, those two simply belong together. Even though we create new materials, there are also great ideas that we would like to reintroduce to the building industry. During the Industrial Revolution, mass production began and concrete buildings developed at an incredible speed. Then people started thinking: okay, now we want well-insulated buildings. So more and more layers were added to buildings. Then people realised the interior climate of buildings had become unhealthy, so people plugged in a machine to generate ventilation. That brought us to a situation where we are completely enclosed in buildings, almost as if we were living on the moon, with everything being controlled by a computer. In doing so we have become disconnected from what we, as humans, actually need. We are now catering to the needs of our buildings, whilst instead, we should be moving in the opposite direction: towards designing buildings that cater to the needs of humans.

Earth-based materials have natural humidity regulation, and great acoustic and insulating properties. The materials are still ‘alive’, meaning they self-regulate and create a completely different indoor experience. Hempcrete for instance naturally expands and contracts with changes in temperature and humidity. When heating is turned off, moisture levels rise, causing the material to expand. As it dries, the hempcrete shrinks again, also shifting slightly with the seasons. Cracks in the wall are inevitable, but if you understand how the material behaves, you can control where it cracks rather than trying to prevent it.

Through workshops, we teach contractors and builders on how to apply our materials. We now know of people who we have trained, and started their own businesses, even taking on public tenders.