Laboratory for a biotechnical company, situated on the Bio Science Park in Leiden. The labs consist of two elongated segments, which can be freely partitioned, joined by a central section that functions as an atrium and entrance hall. The transparent side walls of the building blocks thus created are flanked by screens of perforated steel plating at a distance of two metres. On the outside, the buildings are thus largely hidden from view, whereas, on the inside, there is a remarkably open and light ambience. But the screens are not only there for privacy, they also have other functions. For example, they enable the buildings to harmonize with the scale of the surrounding construction. They are also important in the savings on installations. They serve as a windbreak, so that the glass sliding panels can be opened to allow natural ventilation into the building without there being too much trouble from the wind. Due to a buffer effect, the screens reduce the loss of warmth from the building in the winter. In the summer, they catch much sunlight, so that it remains pleasantly cool inside, despite high temperatures. The spaces between the screens and the buildings serve as reservoirs for the supply of fresh air, and as emergency exits should fire break out. Because the constructions of the screens are linked to those of the buildings, the pressure of the wind on the façades is reduced. Almost ten years after its completion, the Centre for Human Drug Research has been extended with more than sixty per cent of its original floor surface area.