Architecture like an instrument (Pavilion 26)

This is capitalism: you’ve got to sell to survive — you need buyers to sell — you’ve got to attract attention to get buy¬ers. Ever since the reunification of Ger¬many, the Hanover Trade Fair’s man¬agement have not spared efforts and funds to beat the new competition from the eastern lands. Hanover has a handy asset in the form of the World Expo to be held here at the turn of the millenni¬ums. A lot can be done under such an emblem. All sorts of workshops and task groups are being organised on themes like "Industrial Construction and Ecology” or "Art and Design”. Great names have been invited to represent new schemes from the onset. Albert Speer came from Frankfurt to devise the master plan. Herzog + Part¬ner Architekten BDA were commis¬sioned to assess the project in terms of its implementation. The assignment con¬cerned 969,500sqm of the trade fair area, including 470,000sqm of exhibi¬tion halls. The requirements included: clear zoning, highlighting the entrances, roofing over open areas, domination of daylight, and natural materials. A short glance is sufficient to notice that they are best met in Hall 26. The design is based on the large space of the exhibi-tion hall (210x113m) and six inde¬pendent narrow auxiliary buildings along the walls. Today in Germany, you just cannot build a house which would not be “eco¬logical” in one way or another. The same aspirations made EXPO 2000 pick the motto “Man, Technology, Nature”. Herzog fits in well with this slogan, which is actually partly derived from his entry in the 1986 University of Kassel competition. Along with his two collabo¬rators, Reiner Witenbom and Nikolas Lang, he experimented with “intelligent” facades to regulate lighting and ventila¬tion. The secret is above your head, which you are bound to notice getting into Hall 26. As in other projects, the roof received special attention. Design-ing three proud curves, Herzog killed several birds with one stone. As op¬posed to other halls, his does not need to be lit until sunset. At the same time, the sharp sun rays do not enter directly, but they are softly reflected by the curvilin¬ear arches finished partly with metal bands. The same goes for the artificial light after dark. The roof is also a key element of the air-conditioning system. Trapezoid glass ducts with nozzles pump air streams down to create a sort of air canopy above the visitors' heads. Then the air which is additionally heated by people and devices inside the hall goes up naturally. The converging roof¬ing space acts as a nozzle at whose top mobile horizontal wings use Venturi’s effect to regulate the circulation depend¬ing on the suction power and direction of wind, and all of the above is moni¬tored by a computer. And here we have an intelligent building that Herzog talked about. Large halls are usually a boring ar¬chitectural task, there is however something exceptional about this one. The high-tech stylistics of glass and metal was complemented with another material: wood. Herzog treated it as one of the dogmatic tenets of his mani¬festos and projects ever since the eighties. The transversal division of the roof facilitates zoning and orienta¬tion, not to mention the impression of hospitality it creates. The whole shows much care for detail, yet the final ef¬fect is not excessively technological, which I understand was the archi¬tect’s intention. Herzog is known to have said that “architecture should be thought about as an instrument which in the end will be played by the user anyway