European Central Bank, Frankfurt, Germany

The European Central Bank (ECB) realised there was a requirement for a new headquarters building with space for 2,300 personnel. After over 35 sites had been studied in Frankfurt the one chosen was the former wholesale market in the east end (Ostend) of Frankfurt including the Grossmarkthalle building itself (site area of 120,000m²).

A feasibility study was carried out into this site in 1999 by Jourdan & Müller, a Frankfurt architectural firm. The land purchase was completed in spring 2002 and a design competition for the new building was launched in November 2002. By February 2004 the design chosen was Coop Himmelb(l)au, a firm of architects in Vienna, Austria.

The design was modified to ensure the use of the Grossmarkthalle building in the design and to moderate the cost of the project to €500m, based on 2005 prices. Bollinger + Grohmann Ingenieure are the structural engineering consultants for the project.

European Central bank design

The Coop Himmelb(l)au design for the project is composed of three elements (with total floor area of 185,000m²). These include the Grossmarkthalle, a high-rise building consisting of two office towers linked by an atrium and also an entrance building. The entrance building links the high-rise building with the Grossmarkthalle, and also creates a distinctive entrance to the north of the building.

The Grossmarkthalle will house the conference centre (11 rooms) and visitor centre, the staff restaurant, library, foyer and the press centre. The concrete grid structure of the northern and southern façades of the Grossmarkthalle and also the red brick northern projection have been retained as key design elements in the building and have been refurbished. The western wing was also refurbished and the eastern wing has had new windows fitted so that the former refrigeration room can be used as offices (eight floors).

The barrel-vault roof of the Grossmarkthalle will be refurbished (eastern two thirds) and reconstructed (western third) and the entrance building will be integrated into this running across and through it in a diagonal fashion linking the new with the old. The Grossmarkthalle will be illuminated with decorative lighting effects using lighting technology from Luminale and Casa Magica from Tübingen.

ECB tower design

The new double tower for the ECB building will be 185m (north tower) high with a polygonal shape 45 floors and an east-west aspect (south tower will be 165m high with 43 floors). The communications mast will increase the overall height of the towers to 220m.

The double tower will form a new landmark on the Frankfurt skyline when it is completed. The design of the tower has its origins in an attempt to establish continuity with the urban links of the city.

The double towers seem to envelope one another but still allow an atrium in between. These areas will be divided into three with platforms to create space, paths and plazas between the towers (heights of division will be between 45m to 60m). The connecting platforms along with bridges, ramps and stairs will provide multiple links between the offices of the two towers thus promoting communication. The towers will be equipped with 18 elevators of various types.

Progress

The refurbishment and building of structures within the Grossmarkthalle was started in mid-2007. Now in 2008 work is to begin on the new double tower part of the project. In spring 2008 excavation work began for the two basement floors of the office towers and the 650-space underground staff car park in the south of the site.

This initial work will be completed by the end of summer 2008 and then a contractor will be appointed for the piling work of the foundations (97 piles at up to 37m deep) and the construction of the basement slab. The construction is expected to be completed by 2011, when the new building will be ready to occupy.