A mineral wool panel combines the casing and insulation in a single prefabricated element. It can be a good choice for specific fire requirements. However, it has a greater mass than many panels with a foam core and requires edge protection against water. A fair comparison should cover these characteristics together, without reducing the choice to a single slogan. Ready-made mineral wool panels can achieve reaction-to-fire class A2-s1,d0. This is a beneficial characteristic in many applications. However, it should not be used to replace the required fire resistance of a wall. The EI class relates to a specific assembly and duration for which defined functions are maintained. Installation, supports and connections remain part of the solution.