Just How Tall Can You Build A Skyscraper?

[skb12172]

I just saw a news blurb about the new tower in NYC. 101 stories, which will make it the tallest building in the western hemisphere.

I've always been curious as to just how tall our current technology can successfully make a building. What is the limit? What factors limit the size and how could they eventually be overcome?

Also, what is the shelf-life for a skyscraper before it can no longer be upgraded, repaired, reinforced? Fire Away!

[Yogimus]

Depends on the shape, really. A pyramid type of structure would have to be MASSIVE in mass, but could be extremely tall. Still, in the pure hypothetical, you could make that sucker reach outer space, if the theories of space elevators can be trusted.

[Aglifter]

Elevators, wiring, and piping.

At a certain point, your efficiencies become a problem.

As long as corrosion isn't an issue, I don't know that there really is a design life - I think a safe structure means staying well within any kind of stresses which could fatigue the structure - and they are usually meant to have new wiring, etc run into them pretty easily.

Industrial buildings fail with time both because of no cost being spent (at least not more than necessary) to prevent corrosion, and all the lessons from all those "nifty" masonry plants, which cost staggering sums to knock down/renovate, etc.

[Erik]

This seems to be a pretty good summation: http://www.wisegeek.org/how-tall-can-skyscrapers-be.htm
To quote a few parts:

For a long time, engineers and architects have speculated about how tall a skyscraper could theoretically be. Frank Lloyd Wright, considered the greatest American architect of all time, designed a mile-tall (1.73 km) tower, The Illinois. This tower was to be built in Chicago and have 528 stories. It was designed in 1956 and probably could have been built at that time, but at great expense.

Structural materials are not the primary limiting factor on skyscraper height. A skyscraper is surprisingly light for its size; after all, it's mostly empty space. Steel is strong enough to support structures 6.2 miles (10 km) or taller, while advanced composites might support 62 miles (100 km) or taller.

The three primary limitations on skyscraper height are wind, elevators, and budget.
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The elevator factor is another main limitation on skyscraper height. The taller the building is, the more people live and work there, and the more space at the ground floors must be used for elevators.
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The last main limitation on skyscraper size, is, of course, budget. Burj Dubai, the world's current tallest skyscraper at a height of 2,684 ft (818 m) including the spire, cost about $4 billion US Dollars (USD). Assuming costs scale linearly with increased height (a generous assumption), constructing a 6,500 foot (2 km) tall skyscraper might cost $10 billion USD. This is likely around the limits of what developers would be willing to spend on a single project, though only time will tell.

[HTRN]

I just saw a news blurb about the new tower in NYC. 101 stories, which will make it the tallest building in the western hemisphere

1 World Trade is a very, very big building. And oh, it's 104 floors, not 101.

[mekender]

I remember reading that the air in each floor of the WTC towers weighed 1 ton... Air does have weight.

[rightisright]

1 World Trade is a very, very big building. And oh, it's 104 floors, not 101.

I haven't been downtown in a while. My buddy is playing at the Bitter End tonight. If I can shake this head cold, I'm going to head in a bit early and get an ant's eye view of the progress.

[randy]

I remember reading that the air in each floor of the WTC towers weighed 1 ton... Air does have weight.

Does the building structure have to actually support that weight? Or is the air more like the water that fills an underwater structure, part of the over all fluid environment? Does it matter whether or not the structure is sealed,and the air can move freely?

Honest curiosity here. I think I might know the answers, but would not bet on it.

[Yogimus]

Depends on the temperature difference of the inside to outside air.

[blackeagle603]

Have been to obligatory business dinner way up in Taipei 101 a few times. Wished the honorable supplier contacts would have just forgot about me so I could wander and wonder at it. The internal design makes really interesting use of the structural elements as design elements. Functional forms fascinate...