Chicago’s third-tallest building, the Vista Tower, is being touted for it’s unique curvilinear-shaped structure.

It was designed by Chicago’s own Jeanne Gang – which also means that when it opens next year, it’ll be the world’s tallest building designed by a woman. It’s 101 stories and almost 1,200 feet tall.

But it’s the engineering secrets you can’t see that really set this skyscraper apart.

The 83rd floor, with its 25-foot-high ceilings, will be unoccupied. Instead of selling the pricey real estate, Gang and the engineers decided to surround the floor with a permeable screen to allow the wind to blow through the building to reduce the tower’s sway.

(Courtesy Vista Tower EarthCam)

Another technique being employed as a sort of anti-sway ballast are tanks filled with 400,000 gallons of water at the top of Vista Tower.

As Chicago Tribune Pulitzer Prize-winning architecture critic Blair Kamin recently explained it: “When the wind pushes the tower one way, the water will slosh in the opposite direction, joining with the blow-through floor to counteract sway.”

Kamin’s description came from a tour he and Tribune photographer Brian Cassella got of the skyscraper last week. “Few of these elements are visible to passersby, but they’re essential to making the tower stand up – and make a profit for its developers,” Kamin wrote.

He joins us to spill more secrets behind the Vista Tower.

Related stories:

House Hunting: Design Competition Selects Bungalow for the 21st Century

Blair Kamin on NU Athletic Center, Jeanne Gang Apartment Tower

Terra-Cotta Treasures Tell Chicago’s Neighborhood Stories