KA-RZ: A Building Material Made from Coffee Grounds

Every day, billions of cups of coffee generate vast amounts of coffee grounds as waste. Instead of ending up in landfills, this by-product can be transformed into something valuable. Our partner K-MÄLEON has taken up this challenge and developed KA-RZ, an innovative insulating material made from recycled coffee grounds.

The idea came from Olaf Elze, the director of the German company K-MÄLEON. KA-RZ combines dried coffee residues with a natural foaming agent to create a porous, lightweight material with strong thermal insulation performance. The process occurs at room temperature, making it a low-energy and environmentally friendly method. As at least half of the material is organic coffee waste, KA-RZ actively contributes to circularity and reduces the overall carbon footprint.

For the GreeNest project, KA-RZ represents one of the Standardised Packages we are developing together with our partners — practical, scalable solutions that can be applied in real construction projects. By demonstrating how waste can be transformed into valuable building products, KA-RZ shows the potential of innovation to make the construction sector more sustainable.

If you want to know more details on the development process, technical properties, and future applications of KA-RZ, read the full press release.