Giant cantilevers, dynamic angles and a stepped glass tower rise in the skies over the Friedrichswall district of Hanover, Germany, thanks to a new building completed by Behnisch, Behnisch & Partner, Inc. The architecture firm, with offices in Stuttgart, Germany, and Venice, CA, recently completed the Norddeutsche Landesbank (Nord/LB), whose innovative design and environmental responsibility has landed it the Lower Saxony State Prize for Architecture "for enhancing the built environment."
The Nord/LB is designed as the commercial and social hub of the neighborhood, linking residential, commercial and social functions for staff members and residents. "By varying the heights of the complex, the building gently integrates itself into the existing pattern of the city," says Stefan Behnisch, principal and partner of Behnisch, Behnisch & Partner. Behnisch, along with partners Professor Dr. E.H. Günter Behnisch and Günther Schaller, won the project in an international competition.
The 23-story Nord/LB building complex houses 1,500 employees from 16 different branches, which were previously scattered throughout the city. Nord/LB's location, use and size allow it to act as a transitional zone linking the various activities of the city: retail, commercial, residential, cultural, sport and leisure. The linking elements between the city and residential districts are the open and publicly accessible lower floors with restaurants, retail, galleries and a landscaped courtyard.
Toward the center of the building block, a 17-story structure rises, reaching a height of nearly 180 feet. This high-rise tower is a spiraling superstructure built from different volumes set at provocative angles. The angles leave various corners cantilevered, a motif continued in other great multi-leveled masses that appear throughout the visually open composition. The tower overlooks a central courtyard protected inside the building's six-sided exterior. Below the tower, an enormous triangular balcony is raised high above the courtyard.
Part of the ecological concept for Nord/LB are energy saving measures to reduce CO2, control exhaust air and optimize daylighting. The interior "micro climate" of the lower floors is improved by an airflow system utilizing the spaces between the double-skin façades on three outer street elevations.
The upper floors do not need air conditioning. Instead, a soil-heat-exchanger located in the foundation distributes cool air stored by the earth to the floor slabs and releases it slowly into the building. "The building mass is optimized and used as a cooling
element," explains Behnisch. A daylight redirection system integrated into the external sun shading system allows for the use of direct sunlight without glare problems, thus further reducing the need for artificial lighting.