Using prismatic panes, a seasonal shading responsive to the Sun＇s position can be realized. Thus the solar gains from direct radiation can be closely matched to the annual pattern of the heating energy requirements of buildings. The panes are suitable for window or facade elements, preferably in applications which do not need a clear view, and especially in front of transparently insulated solar walls. The direct radiation received on a vertical south-facade is reduced to 10% on clear summer days, while 90% is transmitted on clear winter days.