VO: Our dramatic and beautiful skyline got a new jewel in its crown in 2020.

It's St. Regis Tower by renowned Chicago architect, Jeanne Gang, known for using simple, sculptural forms and subtle color to create beauty, and beauty is especially important here, because this is the third tallest building in Chicago, visible from nearly everywhere.

[Geoffrey] Where does your inspiration come from?

Where do you start?

- [Jeanne] I start from thinking from the inside out.

So like how do you get more different kinds of light in an apartment from different directions?

This started a little bit more like, maybe we could taper the building in and out so that the three parts of it could go in and out of phase, and have more corners.

So instead of four corners, the building has eight corners.

VO: The building block that made this possible is called a frustum.

Essentially, it's a pyramid with the top chopped off.

[Geoffrey] A lot of people have talked about it as a popcorn box, right?

- [Jeanne] That's right.

A popcorn box is a perfect shape of frustum.

- [Geoffrey] Has anyone built a model out of popcorn boxes?

- [Jeanne] Well, in fact yes.

That was one of the ways I used to study it when I was just, you know- - [Geoffrey] Really?

- [Jeanne] Yeah.

- [Geoffrey] Oh, that's amazing.

- [Jeanne] Because it's paper, they're inexpensive, but they also give you, you know, you can eat a lot of popcorn, and you can make a model.

(Both laughing) - [Geoffrey] That's good!

VO: All skyscrapers sway a bit in the wind, but the research showed this one would be so tall and slender, that it would have swayed too much.

So Studio Gang left a high double-height floor open to the elements, allowing the wind to pass through the building instead of pushing against it.

[Geoffrey] I can see why they call it a blow-through floor.

It's windy up here.

I'm not gonna get too close.

VO: The rest of the floors, of course, have windows, offering spectacular views for the lucky few who can afford to live here.

[Geoffrey] Oh my gosh.

- [Sean] Welcome to your new home in the sky.

- [Geoffrey] I'll take it!

(both laughing) - [Sean] That's all I'm gonna say.

I'm gonna let you just soak it in for a little bit.

- [Geoffrey] You've done it, you've done it.

So if I had to whip out my checkbook right now, what are we asking here?

- [Sean] Oh, 19 million-ish.

- [Geoffrey] Hey, a bargain!

So, highest unit in Chicago?

- [Sean] Highest unit in the city of Chicago.

- [Geoffrey] How about that?

Nobody's gonna block your view from here.

How far can you see on a sunny day out there?

- [Sean] On a sunny day, you can see the great state of Michigan.

- [Geoffrey] Unbelievable.

Okay, bathroom with a 14 foot ceiling.

- [Sean] Yes.

(Geoffrey laughs) - [Sean] Let me ask you, are you a music fan?

- [Geoffrey] Yeah.

- [Sean] You could watch Lollapalooza from your bathtub.

- [Geoffrey] The bathtub with the best view in Chicago.

[Geoffrey] So, when you're doing skyscrapers in Chicago, which we like to boast is the birthplace of the skyscraper, what do you think about working in this town?

- [Jeanne] Oh, well I think it's kind of an architect's dream, frankly, because Chicagoans like tall buildings, I think maybe because we don't have a mountain landscape, or some other hills, or things, but the architecture really is the landscape, it's what we're known for in Chicago, and there's that adventurous spirit.