# How tall can a building be?
**URL:** https://boards.straightdope.com/t/how-tall-can-a-building-be/316138
**Category:** In My Humble Opinion
**Created:** [August 8, 2005, 5:50pm UTC](https://boards.straightdope.com/t/how-tall-can-a-building-be/316138 "2005-08-08T17:50:12Z")
**Posts on this page:** 17
**Page:** 1
### Author:  [@ccwaterback](https://boards.straightdope.com/u/ccwaterback)
#### Post date: [August 8, 2005, 5:50pm UTC](https://boards.straightdope.com/t/how-tall-can-a-building-be/316138/1 "2005-08-08T17:50:12Z")
Let’s say we have the technology and materials to build a building as tall as we wanted. How tall could that building be before the effects of the atmosphere, gravity and/or other aspects of the physical universe make it impossible to build any higher?
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### Author:  [@flight](https://boards.straightdope.com/u/flight)
#### Post date: [August 8, 2005, 5:52pm UTC](https://boards.straightdope.com/t/how-tall-can-a-building-be/316138/2 "2005-08-08T17:52:12Z")
What do you define as a building? Would a space elevator count? If so, then geosynchronous orbit.
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### Author:  [@Max\_Torque](https://boards.straightdope.com/u/Max_Torque)
#### Post date: [August 8, 2005, 6:11pm UTC](https://boards.straightdope.com/t/how-tall-can-a-building-be/316138/3 "2005-08-08T18:11:23Z")
I’d say “to the threshold of fear”. You can build a structure as high as you want, but there’s bound to be a limit within the human mind of how high a person is willing to go. Build a 5-mile-tall skyscraper and it’ll turn heads, but who will feel safe working on the top floor when it sways 8 feet during high winds?
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### Author:  [@Ike\_Witt](https://boards.straightdope.com/u/Ike_Witt)
#### Post date: [August 8, 2005, 6:24pm UTC](https://boards.straightdope.com/t/how-tall-can-a-building-be/316138/4 "2005-08-08T18:24:33Z")
> [@Max Torque](#):
>
> Build a 5-mile-tall skyscraper and it’ll turn heads, but who will feel safe working on the top floor when it sways 8 feet during high winds?
While you could build a building that tall, is it practical? So much building space would be taken up by infastructure. I think one of the main problems is getting water up that high in a cheap and reliable way.
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### Author:  [@Finagle](https://boards.straightdope.com/u/Finagle)
#### Post date: [August 8, 2005, 6:42pm UTC](https://boards.straightdope.com/t/how-tall-can-a-building-be/316138/5 "2005-08-08T18:42:46Z")
> [@adam yax](#):
>
> While you could build a building that tall, is it practical? So much building space would be taken up by infastructure. I think one of the main problems is getting water up that high in a cheap and reliable way.
Water, yeah. Not too mention having to pressurize the upper floors. HVAC takes on a whole new meaning when the partial pressure of oxygen falls below values needed to sustain life on the upper floors. Not to mention that if power goes out, you’d need a team of Sherpas to get you down safely.
But I think the space elevator answer nailed it, if you can consider it a building. Some designs I’ve seen have it as a ribbon of superstrong material rather than a building \* per se \*.
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### Author:  [@Ike\_Witt](https://boards.straightdope.com/u/Ike_Witt)
#### Post date: [August 8, 2005, 7:48pm UTC](https://boards.straightdope.com/t/how-tall-can-a-building-be/316138/6 "2005-08-08T19:48:51Z")
> [@Finagle](#):
>
> Not to mention that if power goes out, you’d need a team of Sherpas to get you down safely.
That was another thing that crossed my mind. I remember being evacutated out of an office building. I was on the top floor, the 29th, and it took over 25 minutes to climb down the stairs - I could have gone faster but it would have been rude to knock down everybody else. How long would it take to walk down from the 300th floor?
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### Author:  [@msmith537](https://boards.straightdope.com/u/msmith537)
#### Post date: [August 8, 2005, 8:46pm UTC](https://boards.straightdope.com/t/how-tall-can-a-building-be/316138/7 "2005-08-08T20:46:36Z")
> [@flight](#):
>
> What do you define as a building? Would a space elevator count? If so, then geosynchronous orbit.
I think he meant using current technology. We currently do not have the materials or construction processes for building trans-orbital structures like that.
We can actually build much higher than we do now, it’s just not practical for a variety or reasons.
How tall depends on a number of limiting constraints:
-Materials - how physically tall can we build a structure?
-Economic - how tall SHOULD we build the structure so that it is profitable?
-Psychological - Will people want to work of the 409th floor?
-Logistical - How high can we practically pump water, electricity, elevators, trash removal, HVAC and so on?
-Construction - Even if it could be build, HOW do we actually build it?
-Social - Do we really WANT a mile high monstrosity towering over the city and unleasing 100000 workers on it’s streets every evening?
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### Author:  [@scr4](https://boards.straightdope.com/u/scr4)
#### Post date: [August 8, 2005, 9:14pm UTC](https://boards.straightdope.com/t/how-tall-can-a-building-be/316138/8 "2005-08-08T21:14:04Z")
There’s also the problem of how to transport people to the upper floors. If you double the height of the building, you double the number of people who need/want to go up, which means twice as much space taken up by elevators. It also means twice as much capcity for the associated ground transport infrastructure (parking lots, access roads and subway stations.)
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### Author:  [@Bearflag70](https://boards.straightdope.com/u/Bearflag70)
#### Post date: [August 8, 2005, 9:25pm UTC](https://boards.straightdope.com/t/how-tall-can-a-building-be/316138/9 "2005-08-08T21:25:09Z")
> [@Finagle](#):
>
> Not to mention that if power goes out, you’d need a team of Sherpas to get you down safely.
… fire pole
… parachute
… umbrella
… hang glider
… hot air balloon
… shoes with springs on the bottom
Oh, you said, “safely.”
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### Author:  [@Xema](https://boards.straightdope.com/u/Xema)
#### Post date: [August 8, 2005, 11:51pm UTC](https://boards.straightdope.com/t/how-tall-can-a-building-be/316138/10 "2005-08-08T23:51:23Z")
> [@scr4](#):
>
> …which means twice as much space taken up by elevators.
Or elevators capable of moving twice the number of people per unit time.
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### Author:  [@DMark](https://boards.straightdope.com/u/DMark)
#### Post date: [August 9, 2005, 12:28am UTC](https://boards.straightdope.com/t/how-tall-can-a-building-be/316138/11 "2005-08-09T00:28:58Z")
All those who want the job of window washer, raise your hands.
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### Author:  [@Phlosphr](https://boards.straightdope.com/u/Phlosphr)
#### Post date: [August 9, 2005, 12:36am UTC](https://boards.straightdope.com/t/how-tall-can-a-building-be/316138/12 "2005-08-09T00:36:42Z")
IIRC, Japan has plans for a “city in the sky” where the building they are proposing is a 1/3 larger than any currently standing. The shape was kind of interesting. It was circular with the bottom being very large then tapering all the way to the top, kind of like a reverse funnel shape.
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### Author:  [@WordMan](https://boards.straightdope.com/u/WordMan)
#### Post date: [August 9, 2005, 12:59am UTC](https://boards.straightdope.com/t/how-tall-can-a-building-be/316138/13 "2005-08-09T00:59:20Z")
Google was my friend: [here](http://www.delmars.com/wright/flw7a.htm) is the first result of my search on “Lloyd Wright Mile High Skyscraper”
While not a direct answer to the OP, I thought I had remembers that FLW had designed a mighty high one…
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### Author:  [@Sunspace](https://boards.straightdope.com/u/Sunspace)
#### Post date: [August 9, 2005, 1:03am UTC](https://boards.straightdope.com/t/how-tall-can-a-building-be/316138/14 "2005-08-09T01:03:09Z")
Consider that the railway the Chinese are building to Tibet crosses the 16000-foot altitude, and has _pressurised railway cars_, you’d probably have to start pressurising your buildings around that altitude as well…
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### Author:  [@msmith537](https://boards.straightdope.com/u/msmith537)
#### Post date: [August 9, 2005, 8:45pm UTC](https://boards.straightdope.com/t/how-tall-can-a-building-be/316138/15 "2005-08-09T20:45:37Z")
> [@Xema](#):
>
> Or elevators capable of moving twice the number of people per unit time.
Elevator speeds are limited by acceleration levels comfortible to us humans. We can’t have elevators moving so fast that people fly off their feet. Bigger elevators would require larger shafts, going back to our original problem. One idea is to use multi-level elevators. Another is using express elevators to drop people off at multiple transfer points.
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### Author:  [@Xema](https://boards.straightdope.com/u/Xema)
#### Post date: [August 9, 2005, 9:14pm UTC](https://boards.straightdope.com/t/how-tall-can-a-building-be/316138/16 "2005-08-09T21:14:06Z")
> [@msmith537](#):
>
> Elevator speeds are limited by acceleration levels comfortible to us humans. We can’t have elevators moving so fast that people fly off their feet.
If you keep acceleration and braking at comfortable levels but make them last longer, you can have it both ways - the elevator moves rapidly, but no one flies off their feet.
But at high vertical speeds, problems with rapid pressure changes (e.g. ears “popping”) are of concern. Unless Sunspace’s idea of pressurized buildings catches on, this will probably limit speeds to something like 12m/s.
Perhaps the solution is as you suggest: “stacked” elevators that carry more people with the same footprint.
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### Author:  [@Xema](https://boards.straightdope.com/u/Xema)
#### Post date: [August 9, 2005, 9:21pm UTC](https://boards.straightdope.com/t/how-tall-can-a-building-be/316138/17 "2005-08-09T21:21:05Z")
An extension of the multi-level elevator might be a “compound” elevator: An upper and lower car connected by a cable that allows them to be anything from 1 to (say) 5 stories apart. The pair of cars moves quickly to the general area where they’re needed, then more slowly to the precise floors. Obviously, this could also work with three (or more) cars.
This sort of scheme implies smart building planning, so that demand is distributed and not everyone wants to get to one floor.