Drill Bit building

Not too sure if this proposed Big Screw building will ever even be built, but certainly is an unusual structure. Seems like it might unbalance the skyline, but the other proposal was for two bulky mid-rise buildings without much style. So, in a binary world, I'd choose the funky over the prosaic. If this were a binary decision, which I don't think it is.

In Chicago, Plans for a High-Rise Raise Interest and Post-9/11 Security Concerns - New York Times:
In a city known for its skyscrapers, in an era when tall buildings have become targets, can the skyline handle one more that stretches the limit? In Chicago, it seems, the answer may be yes - if the architect is a “starchitect” like Santiago Calatrava.
...Living in the Calatrava tower would not come cheap, by Chicago standards. Mr. Carley said he expected one-bedroom units to sell initially for at least $600,000, with full-floor units of some 7,200-square-feet topping out at $5 million.

The twisting design, which was recently tested in a wind tunnel in Canada, would disperse Chicago's gusting winds, Mr. Carley said. And Mr. Calatrava designed the interior so that posts and columns would be toward the structure's center, to allow balconies on some floors and maximize the floor-to-ceiling views.

and the Tribune:

A far less well known developer, Chicago's Christopher Carley, will unveil his proposal Wednesday for a slender, 115-story tower with a steel spire that could soar higher than 2,000 feet.

Designed by superstar Spanish-born architect and engineer Santiago Calatrava, the skyscraper would rise next to Lake Shore Drive and near the entrance to Navy Pier. Its tapering glass facade would ripple like folds of drapery.

For Carley, the chairman of Fordham Co., the planned hotel and condo tower would be taller than the combined height of his last three previous projects: two towers of roughly 50 stories and an eight-story structure.

Financing for his latest project has not yet been arranged, and will largely depend on achieving prices rarely seen in a downtown market. “Is this going to get done?” Carley said. “It'll be market-driven.”

But the ambitious proposal, to be called Fordham Spire, would dramatically shift the focus of Chicago's skyline, and it likely faces community opposition and the challenge of obtaining financing in what some are calling an overheated real estate market.
...
The Tribune revealed in May that Carley was working with Calatrava--the architect of the bird-like Milwaukee Art Museum addition, the Athens Olympics sports complex and the planned transportation center at Ground Zero--to design a tower on at least one of two sites along the west side of Lake Shore Drive and the north bank of the Chicago River.

Under Carley's plan, those sites would be combined into a single 2.2-acre parcel at 346 E. North Water St. The area is now an unruly patch, filled with overgrown grass, gravel, trees and a construction trailer.

From it would sprout a tower utterly different from the boxy forms found elsewhere on the Chicago skyline: A skyscraper with gently curving, concave outer walls attached to a massive reinforced concrete core.

Each floor would rotate a little more than 2 degrees from the one below. The floors would turn 270 degrees around the core as they rise, making the building appear to twist.
..
Carley and Calatrava noted that the skyscraper's thin profile--it would have just 920,000 total square feet, compared with 4.5 million for Sears Tower--would make it a benign, not overbearing, presence along the city's lakefront.

That is far better, they maintain, than two towers of roughly 50 and 35 stories, which current zoning allows. Towers of that size would be far more bulky and cast greater shadows, the developer and architect argue.

“The tower is without any doubt tall, but it is not big. It is very slender. It is extremely slender,” Calatrava said.

also Eric Zorn weighs in:

Our other major skyscrapers – the Hancock Center, the Sears Tower, the Aon Center and even the upcoming Trump Tower (see the Trib's Trump Cam for progress) -- have a sturdy quality that fits nicely with our town’s nickname, “The City of the Big Shoulders.”
Now what are we supposed to be? “The City of the Big Screw”?