The Waagenturm is a tower to control the access and weight of the trucks of the BRB, a Berlin-based company for the disposal and recycling of construction materials. In order to reduce the dimensions of the construction the stairs were planned as an exterior area, which covers in the ground floor almost the same space as the closed areas. It is attached to one of the narrow sides of the tower, which is supported by a single central pillar in order to avoid pillars on the corners. The three rooms are distributed in three levels and open to the outer spaces by means of big windows along the façade which also cover the corners. In the first level is the control room, the second level is the director’s office, and in the lower ground floor are the toilets, showers and storerooms. The materials used are the recycled concrete produced by the company, corten steel for the stairs and black profiles for the windows. + link +