The most commonly used insulation materials currently consist of synthetic or mineral raw materials or biobased-synthetic mixtures that cannot be returned to the resource cycle. The use of unmixed biological insulation materials in conjunction with reversible construction techniques is an elementary component of a circular strategy. Sandra Böhm and Daniela Schneider are conducting research at KIT Karlsruhe and are focussing on the resource-conserving use of materials and circular constructions.