Why the world's 2nd tallest building twists on purpose

The Shanghai Tower is 632m tall - the second tallest building in the world - and it twists 120 degrees from base to top. That spiral isn't decoration. A straight, flat tower gives the wind a huge face to push and shake, but a twisting, rounded tower never shows the wind the same face twice, so the swirls can't organise into a push. The twist cut the wind load by 24% and saved around $58 million in steel. The shape is the engineering. Full breakdown on the channel. Free structural engineering too