The 40 story high-rise headquarter of the Deutsche Post AG in Bonn features an integratedcomfort and low energy concept. Contrary to common high-rise design, the building does not require a central mechanical ventilation system. Instead it is decentrally ventilated by a double faade, which decreases wind loads and allows for natural ventilation through window openings.The typical floor plan is designed to provide a cross ventilation from the double faade through officerooms to a central atrium serving as exhaust duct. This allows an elimination of any vertical airdistribution shafts, saving space - a major improvement in respect to the building's efficiency. In addition, one story for mechanical installations is eliminated using decentralized air intake units in the standard under floor convectors.