The portal buildings have quite a discreet appearance, through form and use of materials. They are only visible from a short distance. This building has a horizontal form of expression, which is emphasised by the flat, sod-covered roofs. The immense, grey-coloured, concrete surfaces are untreated, but the marks left from the casting frames provide life and rhythm to the wall. The lower-part of the building, which has several gate openings, is articulated by way of pillars, while the upper section is characterised by a horizontal row of windows.