Basically it must be distinguished between the mounting and planning of solar panels on new or old metal roofs. If it is a new roof, the expected snow- and windloads can be aimed. The panels must be attached with enough clips to the building structure to carry those loads. Norms like the German Institute for Standardization 1055 for wind- and snow loads are to be followed. On a old roof the panels and seams must have enogh flexural strength and the structural analysis must be able to carry the additional loads. Edge and corner areas