The new ECB headquarters building is a new typological approach to tall building design. The naturally ventilated atrium is a buffer zone with minimal thermal conditioning, offering spatial and communication potential in the form of a vertical city. Office workers coming and going via the atrium are offered magnificent views of the city and a sense of connection with the whole spatial volume enclosing the institution. The location of the lift cores in the atrium also allows more efficient spatial organization of the office towers. The façade incorporates an array of devices which offer a high degree of selectivity and adaptability, including selective glass coatings, automatically controlled movable solar shading and elements specially developed to allow the natural ventilation of a high-rise building in a windy environment. The office spaces are conditioned with low energy climate control systems using 100% outdoor air ventilation systems and large surface area radiant heating and cooling systems. Waste heat from the buildings data center makes a substantial contribution to meeting the building’s heating energy demand.