This is 99% invisible. I'm Roman Mars.

Happy New Year, beautiful nerds. It's 2024 and it is mini stories volume 18.

To ease us into the new year, we have stories of buildings constructed from the

sky to the ground, the little filler words that convey nothing and everything at

the same time, and a song about a fire that never goes out.

Let's do it.

So I'm here with Kurt Colstead, digital director and co-author of the 99% invisible city,

and you are here to tell us about the newest most unlikely craze in skyscraper

construction. What do you got? Yeah well we've already covered a lot of

different ways of putting up and taking down buildings on the show and in our

book. And you know there's bottom up construction

and there's both top down and bottom up demolition,

which are pretty fascinating.

But now there's actually something in that fourth quadrant of building that I don't think we've ever talked about before and that's top-down construction.

Okay, you're gonna have to break this down for me because I cannot imagine how you build a skyscraper from the top.

Yeah, yeah, good question.

So there's this new tower in Detroit, which is a great example of this.

It's called Exchange, and its levels were built in reverse order, the top floor first and the

ground floor lapse. Here's a photo that kind of shows you how this is working like midway through the

construction process. Okay I see so it kind of looks like the top half of a skyscraper

but with legs on it. So I gather that these

thick concrete pillars are kind of holding up the top half of the skyscraper.

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