Description
The new building of the Norddeutsche Landesbank [State Bank of North Germany] was realised by the architects Behnisch, Behnisch & Partner. It is situated at the interface between the business centre of Hanover and the residential areas of the southern part of the city. It was important to the architects to stabilise the street space with an urban design form typical of Hanover. In the middle of the development however, a central building rises to a height of 70 metres. This taller building segment detaches itself from the regimentation of the primary perimeter of the block, developing freely in accordance with different laws based on higher-ranking references and forming a landmark. This defines the transition from the ‘noisy’ city to the quieter residential areas. The linking of the residential and the business districts is provided through an open ground floor area, to a large extent freely accessible. There one finds restaurants, small shops and coffee bars. Large expanses of water run all the way through this open area of the inner courtyard, which offers a relaxing resting place for passersby and employees.
The multi-storey entrance hall lies at the centre of the site and is accessed via a square in front, through an opulent ‘gate’. Through the centrally placed hall it is possible to reach both the special areas and all the office floors by the shortest possible route. The individual building segments have varying office depths, so that a variety of office types – open-plan, individual, combination and group offices are possible. In the offices, importance was attached to creating a comfortable, light work atmosphere. For this reason, the corridor walls were extensively glazed. All glazed surfaces were executed in clear glass for maximum transparency.
Terraces facing in different directions are situated in front of the staff lounges on many floors of the buildings and can be used by the staff in their breaks. In the taller building segment are located the prestige areas like the restaurant for guests, meeting rooms and the offices of the board of directors. For the sides, facing onto noisy streets, a double façade was planned, one that would provide protection against high noise levels even when the windows were open. Fresh air is drawn from the inner courtyard, passing under the building mass and into the double façade. The expanses of water in the inner courtyard and the densely planted roof terraces provide an improved microclimate.
In the summer months, cold water is piped into the ceilings of the reinforced concrete structure, increasing thermal mass by exploiting the earth’s cooling capacity as a heat exchange buffer. At night, fresh air is flushed through all the rooms via vents in the façade and waste air ducts in the corridors of the buildings; adjoining structural elements retain the coolness of the night air and release it again in the course of the day.
Drawings
Site plan
Third floor (typical floor)
Eighth floor
Cross section
Photos

Exterior view

Night view of the high-rise building and inner courtyard
Originally published in: Rainer Hascher, Simone Jeska, Birgit Klauck, Office Buildings: A Design Manual, Birkhäuser, 2002.