A vertical garden city – The Unité d’habitation, ‘Berlin Type’
Between Heerstraße and the Olympic Stadium, on Heilsberger Dreieck, Le Corbusier’s massive high-rise slab apartment block Unité d’habitation ‘Berlin Type’ rises up, visible from afar. A contribution to the international architectural exhibition Interbau, the 17-storey building with its 530 apartments couldn’t be constructed in the Hansaviertel due to the building’s size and the plan for it to be set in a large green area. The site for the Unité was chosen by Le Corbusier himself because of the area’s size and the good transport connections. As a “vertical city”, the Unité reaches upwards, thereby taking up a relatively small ground area and allowing the surroundings to be shaped into a spacious parkland, offering sun, space and green. As the structure was elevated, the open space could even pass under the building, and each apartment had at least one loggia on the front, allowing a connection to the surrounding green space. Le Corbusier also used the loggias as a striking way to structure the façade horizontally, the elevator tower being the only vertical interruption.
The concept of a self-contained city is also apparent inside the Unité. Just like streets in a city quarter, there are ten “streets” inside (rues interieures), each about 3 metres wide and 140 metres long, providing access to the individual apartments. For ease of orientation, the apartments were given ‘house numbers’ and front doors of different colours. There were also shared facilities in the building. In the mostly glass entrance hall there were public telephone boxes and a post office. A shop was added for the residents’ daily shopping needs, and there was a laundry room on the 17th floor. Another characteristic of the building is its orientation towards one- and two-person households. Of the partly two-storey apartments, 440 were designed as one- or two-room apartments, 85 as three-room apartments, only four as four-room apartments and merely one five-room apartment.
Despite its remote location, the Unité d’habitation ‘Berlin Type’ was one of the main attractions at Interbau thanks to the architect’s renown and the spectacular nature of the project. Le Corbusier had already built one Unité in Marseille and another in Nantes, but the Berlin Unité was the first outside France. (1) In contrast to its French predecessors, the ‘Berlin Type’ is a compromise between Le Corbusier’s design and the regulations and views of the Berlin authorities. This meant that the room height of 2.26 meters – developed according to Le Corbusier’s modular measuring system – was not adopted, but instead a uniform height of 2.50 meters was stipulated. In the two-storey apartments, the intermediate ceiling had to stretch to the exterior wall, meaning there could be no two-storey rooms. Moreover, the shared floor with its shopping facilities was originally envisaged by Le Corbusier for the seventh floor so that the residents from the upper and lower floors would have roughly the same distance to go to get to the shops. The orientation towards small households was also not consistent with the ideas of Le Corbusier, who had first and foremost planned large flats for large families. The housing of families in high-rise apartment buildings was considered unsuitable by the Berlin authorities, however.
Furthermore, the Berlin Unité and its sister buildings in France were considered part of the solution to the housing shortage after the Second World War and to the reform of old city structures. In 1945, Le Corbusier drew up the designs for the reconstruction of St. Dié, planning a loose grouping of eight Unités in one large scenic green area. There followed plans for the development of La Rochelle-Pallices (1946) and for Meaux (1956), for which several Unités were intended, but none of these plans were in fact carried out.
“To sell democracy abroad” – The Congress Hall: a gift from America to Interbau
Its outstanding shape and masterful setting made the Congress Hall a particular crowd-pleaser and a picture postcard favorite at the architectural exhibition Interbau. Positioned on an artificial mound and base, it was visible from afar in both the east and the west. Viewed straight on, the structure and its curved roof were reflected in the water to form an oval. A wide flight of steps ennobled the structure, and the bright white paint of the roof bolstered the long-distance effect.
The Congress Hall was built in Berlin between 1956 and 1957 thanks to the substantial efforts of Eleanor Dulles, who worked in the U.S. State Department Office of German Affairs. The building was intended to send a strong political message, a symbol of German-US friendship. Thus, the Congress Hall was affiliated with two other symbolic Berlin buildings, namely the Amerika Gedenkbibliothek (1951–55) by Fritz Bornemann, Gerhard Jobst, Willy Kreuer and Hartmut Wille, and the Amerika Haus (1956–57) by Bruno Grimmek. Located near the border between the two Germanies and on an axis with the Reichstag, the Congress Hall was also meant to be “a beaming beacon shining towards the east”. (2) Alongside its original designation as a cultural, economic and scientific space, from 1957 the Congress Hall also served the German Reichstag, which held several sessions in the large congress hall – the auditorium – equipped with innovative technical features, such as air-conditioning and an interpreter system.
American architect Hugh A. Stubbins, once long-time assistant of Walter Gropius at Harvard University, was chosen for its architectural execution. In the summer of 1956, the final draft was received: a shell construction with a hyperbolic paraboloid roof, underpinned by only two points of support at the ends. The roof was designed to span the oval auditorium, which had its own internal roof, and an expansion joint was meant to highlight the static conditions. In this plan, both design and engineering complied with the desired basic principles of functionalism. The roof as developed by Stubbins and Fred Severud, with its self-supporting concrete shell construction, was considered an innovative testimony to engineering.
However, difficulties emerged while executing the plans. The Berlin authorities doubted the stability of the roof construction and therefore constructed a modified version of the original plans. The roof was supported on the bearing walls of the auditorium and a roof projection was added. An edge beam was meant to provide stability but further weighed down the roof projection. With this replacement construction, the appearance of a self-supporting shell construction was indeed preserved, but it thwarted the requirement of the functionalist-influenced Stubbins and his contemporaries for a shape to develop out of the construction. Moreover, several architects doubted the stability of the replacement construction and suggested alternatives, which were ignored by the Berlin authorities. After vigorous debate amongst the experts and in public, the Congress Hall was finally opened on the 19th September 1957 during the Interbau exhibition. (3)
Indeed, the roof only held for 23 years. On 21st May 1980, the southern roof projection collapsed. This time the discussions were more relaxed about whether to reconstruct or completely demolish this example of post-war modernism, now derided by some as “kidney-shaped table” architecture. This attitude was partly down to Germany’s image of the US having changed due to the Vietnam War, the arms race with the Soviet Union and the stationing of Pershing missiles in Germany. (4) However, the discussion came to an end in 1982, when the Senate declared the Congress Hall a “visible sign of German-US solidarity in the city”. (5) The roof was reconstructed, this time in its original design as a shell construction, with the Congress Hall re-opening in 1987 on the occasion of the 750th anniversary of the City of Berlin and the IBA 84/87. Since 1989, it has served as the Haus der Kulturen der Welt to promote understanding among nations.
Dr. Sandra Wagner-Conzelmann