Nicholas Grimshaw and Partners has won a competition to design a new hall for Frankfurt's internationally renowned trade fair area, the Messe (above). The new building will complete the southern perimeter of a large urban square within the Messe known as the 'agora'.
To allow the building to present a 160m-long glazed elevation to the square, the structure spans not the width but the length of the building, making it, according to the architect, one of the widest-spanning column- free spaces in Europe.
The structural steel members form a single continuous folding grid in one plane, with the compressive and tensile zones clearly distinguished. The former comprise a series of anticlastic tensile nets occupying the lower convex parts of the roof geometry, and the latter are tubular gridshells which occupy the upper concave portions.
The roof deck will be formed from giant stressed-skin prefabricated panels consisting of two profiled steel decks riveted together with their troughs aligned in opposite directions. The structural geometry will require these to be made with an in-built twist, but the repeating nature of the roof means there will be 'only' 60 different panel types. This deck will be clad with a proprietary aluminium standing-seam roofing system.
Services are also accommodated in the double-deck structure to maintain the clarity and integrity of the roofline. Clerestory glazing accentuates this further, as well as bringing natural light into the heart of the building's deep plan. The contract sum is £80 million. Work is due to begin on site in February 2000 for completion before the 2001 German Motor Show in 18 months' time.