The tower is the highest building in the city and a landmark of the trade-fair grounds. To maintain visual links between the northern site entrance and the landscaped open space to the south-east, the tower was oriented on the diagonal. By locating the two access “cores” outside the building, it was possible to create a transparent entrance hall. The square layout of the tower, with office areas of roughly 400 m2 per storey, allows up to 20 workplaces on each of the upper floors to be located next to the facade. The external cores, situated at opposite corners of the building, have clay-tile facades and provide shading to the glazed south and east faces of the office tower. Heating and cooling are based primarily on the thermal activation of the solid volumes of the building, including the unclad floor slabs. Internal heat sources (people, equipment, lamps, etc.) are more or less sufficient to heat the building. Unwanted thermal gains from insolation in summer are removed directly – without entering the offices – by the large volume of air flowing between the inner and outer facade layers. Flint glass was used in the outer skin to ensure greater transparency. Th.H.