The building section comprises a wall and a peripheral window case, into which a window frame is inserted. The window case comprises several support sections arranged a certain distance apart and standing laterally out from the wall, each support section comprising a support part and an insulating part. The first leg of the support part is screwed to the wall, whereas the window frame is screwed to the second leg of the support part. The insulating part surrounds three sides of the second leg of the support part. In the areas between the support sections, the window case comprises insulating sections. The insulating parts of the support sections and the insulating sections bring about a substantially continuous insulation of the window frame around the window case.

The building section comprises a wall and a peripheral window case, into which a window frame is inserted. The window case comprises several support sections arranged a certain distance apart and standing laterally out from the wall, each support section comprising a support part and an insulating part. The first leg of the support part is screwed to the wall, whereas the window frame is screwed to the second leg of the support part. The insulating part surrounds three sides of the second leg of the support part. In the areas between the support sections, the window case comprises insulating sections. The insulating parts of the support sections and the insulating sections bring about a substantially continuous insulation of the window frame around the window case.