European Investment Bank
A Building For All Seasons: Located on the Luxembourg City’s Kirchberg Plateau, the European Investment Bank addition endorses sustainability with a spirited tubular glass design that ensures year-round high performance.
Visitors to the city of Luxembourg know it mostly as a picturesque medieval destination—a UNESCO World Heritage site—with its distinctive historic wall, castle, and cathedral situated high on cliffs surrounded by a meandering river. But there is another part of the city less known to tourists but no less important—a newer district called the Kirchberg Plateau, situated northeast of the old city, and housing various European Union (EU) institutions, cultural buildings, and business headquarters. While the old city preserves history, the new one functions as the heart and capital of the EU.
Based on what you have seen and read about this project, how would you grade it? Use the stars below to indicate your assessment, five stars being the highest rating.
Though probably the least famous of the EU member states when it comes to the arts, Luxembourg City still endeavors to promote culture and embrace interesting modern design. A collection of architecturally significant buildings has been built on the Kirchberg Plateau. Among them is the Museum of Modern Art (MUDAM) designed by I.M. Pei (2006); the Philharmonie, a concert hall designed by Christian de Portzamparc (2005); and the new twin high rises of the Court of Justice, completed by Dominique Perrault (2008).
Standing near Perrault’s towers and joining this new generation of modern buildings, Christoph Ingenhoven’s addition to the European Investment Bank (EIB) is the first here to marry green design with high design. Opened in 2008, the building connects to and complements the existing bank headquarters buildings designed by British architect Sir Denys Lasden in 1980 and 1994, which together occupy a stretch between Boulevard Konrad Adenauer and a wooded valley called the Bons Malades. Linked to the existing complex by a third-floor extension, the new facility resembles a giant greenhouse, but instead of housing plants, it contains 750,000 square feet of space including offices for 930 employees, public spaces, parking, and dining areas for many of the 2,230 employees who work in the three buildings.
It’s fitting that the EIB would want to occupy a green building. As the primary long-term lending institution of the EU (and the biggest investment bank in the world), the enterprise earmarks a substantial portion of its loans to projects that protect the environment. In 2001, it initiated a design competition and the jury and client unanimously selected Ingenhoven Architects’ team. “The jury decided on [the basis of] program compliance, whilst the client emphasized the sustainability, flexibility and communication aspects in our design,” said Ben Dieckmann, managing director of Ingenhoven Architects. Spanish architect Ricardo Bofill served as the jury chair. He imagined the Kirchberg Plateau as a citadel with a dense wall around it. Located at the edge of the plateau where the land descends to the valley, Bofill imaged “our building as part of that wall,” explains Christoph Ingenhoven, principal in charge.
Founded in 1985, Dusseldorf-based Ingenhoven Architects has emerged in recent years as a premier designer of green buildings. They have completed high performance projects in Europe, Japan, and Australia, but have yet to be engaged or broadly recognized in North America.
Ingenhoven’s design for the EIB includes a curvaceous glass shell that envelops an inner glass structure—a building inside of a building—which work in tandem to modulate natural light and mitigate temperatures between the indoors and outdoors for energy efficiency and employee comfort. The outside enclosure consists of double-skinned glazing, while six to nine stories of offices inside have triple-glazed timber facades. “The three-story height difference [of the interior volumes] is due to the extreme topography of the site,” explains Ingenhoven. Underneath this volume are three levels of underground parking. “Fortunately the site is quite solid rock so that there was no problem with the steep valley behind the building,” remarked Frank Tarazi, structural engineer, Werner Sobek, Frankfurt.
The seven office blocks zigzag back and forth inside the larger enclosure. In the intermediate spaces between the zig and the zag are unheated winter gardens on the north-facing side, which look onto the woods of the Valley of Bons Malades. On the south-facing street side are column-free public atria for circulation and gatherings, where moderate temperature control is provided by underfloor heating. Naturally ventilated year round, both winter gardens and atria function as thermal buffers for the office volumes, resulting in highly controllable climatic zones. Office windows open to atria and winter gardens, which are themselves naturally ventilated with automatic controls. “Triangular flaps on the curved roof are the ventilation flaps for the winter gardens, while ventilation lamella flaps in the vertical facades of the south-facing atria provide air intake to these more populated areas,” explains Dieckmann.
While employees can control comfort systems, efficiency is maintained with automatic resets throughout the day. Adjustable sun-shading screens over the interior glazed volumes help too. “Opening width [of the flaps] for natural ventilation is set according to temperatures in the atrium, outdoors, and wind velocity,” explained Dr. Michael Bauer, managing director, DS-Plan. Notwithstanding high-tech efforts for optimum energy performance in the building, the City of Luxembourg required that the project utilize district heating and cooling as part of the scope. “We could influence the amount of energy spent but couldn’t influence the way energy was given,” explains Ingenhoven.
With the north side of the building dedicated to the drama of the steep valley, circulation and entrances occur along the south. Dining areas are situated off of the third-floor connecting corridor that links to the original complex with access onto an outdoor terrace. In this public area, installations of “large scale art compliments the building. The EIB arts committee was set up to build up a permanent collection of significant work reflecting trends in contemporary art in the EU,” explains Enzo Unfer, director of facilities at EIB.
The transparency of the external envelope is reflected internally through a variable office plan—offices and their related support services can be easily moved, combined, or readjusted. In addition to various meeting rooms, each level has a central zone, which serves as both an informal meeting area and cafe. These areas occur at the intersections of the triangular shape, encouraging interaction and contributing to a collaborative work environment.
Large glazed areas of the inner office walls are timber-framed. While Ingenhoven prefers to use wood from Canada, the client wanted to save carbon by transporting Russian pine from closer-by Siberia. Ingenhoven doubts the savings were significant—given Siberian wood travels via old Soviet truck, while wood from Canada comes on a high-tech ship. It is “very hard, very tough, from the very far north,” which ensures its durability, says Ingenhoven. Not only is the wood 100 percent FSC-certified, but it exceeds the requirements of BREEAM.
The building complies with the most stringent environmental standards. It was the first building in continental Europe to be awarded BREEAM certification. “BREEAM assessment was ongoing with the aim to serve as an example for environmentally friendly public buildings of the EU,” commented Tarazi. The designation of “excellent,” was bestowed on the project, the highest category of performance possible in the rating system.