So far, the FortySeven & Co in Frankfurt on Mainzer Landstraße has been reported on primarily with regard to the self-supporting façade made of natural stone. Now a blog post points out that a plastic-free material based on stone raw materials was also used for the insulation – mineral wool. In addition to the excellent insulation performance, the long durability, fire resistance and flexibility during installation also played a role in the decision. The article quotes Manfred Wenzel: “Mineral wool has much higher sustainability criteria than comparable insulation materials. In addition, there is another important aspect, namely fire protection – even during the construction phase. … For this reason, we use non-combustible material in the insulation wherever possible.” The mineral wool insulation has contributed to the FortySeven & Co being awarded LEED Gold certification.