Designed in Hong Kong by Norman Foster, the HSBC Main Building reverses the usual structural logic of the skyscraper: instead of supporting the floors from below, it hangs them from above.

In a conventional tower each floor rests on the columns beneath it and the load flows downward. Foster instead built the building on a double row of giant steel masts. "Coathanger trusses" springing from these masts — borrowed from bridge engineering — suspend the floors from above in groups. The result is that there are no load-bearing columns in the interior; each floor is an open, flexible slab from end to end. The suspension system also frees the ground: the underside of the building is left as a public covered plaza, and people can pass beneath it.

The structure was almost entirely prefabricated off-site: steel components, service modules, and even toilet units were prepared in factories, shipped to Hong Kong, and assembled on site — not a building so much as an orchestrated assembly process. With features like the external "sunscoop" that reflects sunlight into the interior atrium, environmental design too becomes part of the structure. The HSBC is thus a mature example of high-tech architecture uniting suspended steel structure, prefabrication, and column-free flexibility.