Taking into account all fire protection requirements for curtain walls, ISUM M14 can be used for the thermal insulation of a façade. As with over-rafter insulation, ISUM M14 requires an air layer on both sides to ensure the degree of heat reflection of up to 96% and, when installed, counts as part of a curtain wall. The corresponding fire protection requirements are clearly defined in the building regulations (LBO), special building regulations and guidelines. In addition, depending on the size of the building, use and equipment, further guidelines and regulations must be observed. Normally flammable external wall cladding (e.g. wooden facades) may be used on most buildings up to 7 m high. However, for buildings of average height of 7 to 22 m, at least flame-retardant façade claddings are required. Only non-flammable materials must be used in high-rise buildings. Most federal states require a permit for curtain walls, and design regulations may apply in individual cases of external building alterations. A building project can only be approved if it complies with both building planning and building regulations (this may also include a fire protection certificate) and if all relevant public legal provisions are complied with. If ISUM is to be used in a curtain wall, the manufacturer’s technical adviser and the relevant building supervisory authority should be consulted.