invention is associated with a roof window 1 comprising essentially a sash frame 2 and a sash or hinged leaf 76 arranged to open on hinges at the side that is by pivoting about a horizontal axis 3 this invention is concerned more particularly with roof windows of the type projecting somewhat above the top 4 of the roofing according to this invention this roof window 1 is provided with a rolling shutter 5 comprising an apron 8 consisting of a plurality of parallel blades 9 10 11 the lateral ends 12 of the apron blades 9 10 11 are slidably engaged in lateral guide rails 13 having their lower ends not shown interconnected by a cross member also acting as a stop member to the apron 8 the upper ends 14 of guide rails 13 abute that inlet outlet aperture 15 of a casing 16 since this casing 16 is intended for enclosing the apron 8 in its fully rolled up condition its height 17 must necessarily be slightly greater than the winding diameter 18 of the rolled up apron 8 to provide a free gap for the passage of foreign matters such as leaves stones or the like possibly carried along into the casing 16 in spite of the presence of a brush 19 disposed at the inlet 15 of said casing 16 however it is advantageous that the height of the roof window 1 above.