Vista Tower To Get Empty, ‘Blow-Through’ Floor To Reduce Swaying From Wind

It will be the first building in Chicago with a blow-through floor.

June 11, 2019 - 1:06 pm

CHICAGO (WBBM NEWSRADIO) -- A building which will eventually be Chicago’s third tallest is going to have one floor that lives up to the city’s nickname.

Vista Tower, in the 300 block of East Wacker Drive, will include an empty “blow-through” floor on the 83rd floor, to reduce swaying in windy conditions. 

"We call this the blow-through floor. This is the 83rd floor of the building," said Sean Linnane of the Magellan Development Group. He tells CBS 2 the blow-through floor will allow wind to whip through the building and create less of a sway among its three towers than most skyscrapers undergo.

“A blow-through floor is a way to – as the structural engineer and the wind engineers describe it – confuse the wind, and basically dissipate some of the effects of the wind,” Linnane said.

“Whatever direction the wind comes through, or comes from, we can alleviate that pressure."

Blow-through floors are already found in buildings outside Chicago, but this will be a first for the Windy City.

The Council On Tall Buildings said most of the city’s taller structures, like the Willis Tower, sway several inches each day.

When complete, the Vista Tower will stand nearly 1,200 feet tall.

The need for a blow-through floor was discovered when architects were testing a model of the building in a wind tunnel.