The department store "Galeria Kaufhof" at Alexanderplatz, planned and realised in 2004-2006 according to plans by Kleihues + Kleihues, is to be supplemented by a 146m high high-rise tower and an 8-storey extension of the existing building. The uses are independent of each other and are largely accessed separately. The high demands on inner flexibility and general sustainability are taken into account in the planning – they range from a smart façade to weight-saving cap ceilings.