Grimshaw’s design completes the southern perimeter of a large urban square known as the ‘Agora’, presenting a 165m long, fully glazed elevation. The structure spans the length of the building to present an open facade. Laid out over two storeys, the design comprises 40,000 sq m of exhibition space, fed by twin blocks of four-storey foyer access, one occupying each short side. The roof is essentially a single, giant, folded plate structure formed from a continuous network of welded steel tubes spanning 165m. Its deck is formed from stressed skin prefabricated panels consisting of two profiled steel decks. There are only sixty different panel types keeping manufacturing costs to an absolute minimum. Clerestory glazing draws daylight deep into the heart of the building, accentuating the clarity and integrity of a roofline that is unimpeded by plants and service ducts. These are absorbed into the double-deck that separates the upper and lower exhibition halls. This deck accommodates the high-level pedestrian access route that serves the existing Messe.