The Waagenturm is a tower errected to control the access, weight and billing of the trucks entering and leaving the BRB, Baustoffe Recycling Berlin GmbH, a Berlin-based company specialized in the disposal and recycling of construction materials. In order to reduce the dimensions of the construction, the staircase was planned as a slim, exterior structure. It is attached to one of the narrow sides of the tower and is supported by one central pillar in order to avoid pillars on the corners. The three rooms are distributed on the three levels and open to the outer spaces by means of big windows opening the façade horizontally, even on the corners. The control room is on the first level, the director´s room on the second level, on the lower ground level toilets, showers and storage rooms are installed. The materials used are the recycled concrete produced by the company, corten steel for the stairs and black profiles for the windows.