

Ask YC: Why aren't high-rises built by machines? - oldgregg

I have zero background in construction, but was just thinking about this...<p>It seems like erecting a high-rise is pretty well-defined by architects and engineers-- so why can't machines be built to automate much of the process? Even if that meant having a very  standardized building, it seems like it would be so cost efficient that the aesthetic compromise would be alright.<p>I know there is pre-fab housing.. it's cheaper, but the savings are negligible. But it seems like economy of scale would really kick in with large buildings. I know it would be expensive initially. Plenty of new R&#38;D and engineering hacks.<p><i>I just want a giant machine that I put on a plot of land, feed it concrete and glass like an easy-bake oven, and 3 weeks later I have a giant high rise.</i><p>Why hasn't this happened?
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gravitycop
_Even if that meant having a very standardized building, it seems like it
would be so cost efficient that the aesthetic compromise would be alright._

Skyscraper tend to be designed to be iconic, e.g. non-standardized. Building
codes evolve, which also defeats standardized construction.

The new Freedom Tower (One of the World Trade Center replacements; a symbolic
1776 feet high), a hyper-iconic building, is lately estimated to cost around
$1,000/sqft of floor area to construct. Simpler skyscrapers can cost as little
as $200/sqft, so that's your competition. Your proposed venture needs to be
able to 1) complete skyscraper projects at substantially less than $200/sqft,
2) meet building codes, and 3) convince authorities to grant construction
permits for a radical construction technology.

Skyscraper construction, like house construction, is already automated to a
great degree. Parts are mass produced in centralized factories, shipped to the
construction sites, and put together like parts from a kit. Here is the brand
new Trump Chicago being built with a helicopter delivering prefabricated
parts:
[http://forum.skyscraperpage.com/showthread.php?s=000ea7e2e81...](http://forum.skyscraperpage.com/showthread.php?s=000ea7e2e819b916c360907870a05ae9&t=128533&page=296)

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astrodust
I would suggest the major problem with constructing buildings like that
automatically is that each floor has to be carefully prepared with reinforcing
material long before the concrete is poured. I think for this reason alone
you're going to find trouble.

While the arrangement of these rods is a fairly straightforward but tedious
process for a human to do, it's particularly tricky for a machine to manage
because of the highly variable nature of the structure.

If you had some kind of construction material that didn't require internal
reinforcing, where it could be just applied as-is, then you would see a lot
more automation.

As others have said, building codes and quality control would have to play a
part here. A lot of automated manufacturing is subject to strict checks, but
usually the resolution for a defect is to discard the part. In the case of a
building, or even a part of it, that may not be so easily accomplished.

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gravitycop
_why can't machines be built to automate much of the process [of erecting a
high-rise]?_

This might be a good place to look for answers:
<http://forum.skyscraperpage.com>

The engineering section discusses construction technology.

~~~
oldgregg
That's spot on, really interesting discussions.

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likpok
There have been a few recent developments (I remember hearing about a concrete
3D printer), but it seems that the technology just isn't there yet. The
problem is that the robots need to be small (enough to be transportable and
reusable), cheap (cheaper than construction workers) and mobile (small => you
need many to slowly build up the building). Most robots don't have that level
of sophistication yet. All the manufacturing robots are stationary and
(relatively) large, and mobility is something of an unsolved problem.

This is not to say that it is impossible, just that I think there are
significant engineering hurdles to robots building skyscrapers (maybe smaller
houses first?).

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pg
It makes most sense to manufacture things when they're small, cheap, and made
in large quantities. High-rises are at the other extreme.

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russell
I saw 0.01 version of one in San Mateo, CA about 20 years ago. The building
was built from the top down. Each floor was built on the ground, cast
concrete, I believe, and hoisted into place underneath the one on top. It
probably didnt have any real advantages, because I havent seen it done again.

One would thing that simple, but well designed and constructed, housing would
dominate, but it hasnt happened. Construction codes are one thing, but I think
the real reason is that nothing can compete with fine contros and flexibility
of humans when it comes to building large structures.

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czcar
There attempting to build something like this,
[http://www.engadget.com/2007/01/15/rival-robots-prepping-
to-...](http://www.engadget.com/2007/01/15/rival-robots-prepping-to-automate-
home-building/) . Personally I think its a horrible idea, I have a gross
aversion to suburbia clones, let alone soviet style skyscrapers that all look
the same. But I suppose it would be interesting. As gravitycop pointed out
skyscrapers more often than not are ego plays so the more outlandish the
better.

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deepblue
the machine does not have to be big... it can be a bunch of small spider like
machines, or even more groups of machines: \- material suppliers \- welders \-
concrete ones (these can be essentially carrying tubes that are pump out
concrete)

this might be the next step for building multilevel farms, for agriculture
(building huge pyramids). I've seen mockups/studies done in Japan (I think)
that talk about exactly this, spider like swarms of robots moving along rail
like structures maintaining/buidling fractal like pyramid structures that are
super-tall ;))

the only way to take agriculture/housing to the next level... have multi-level
cities (and not what pseudo-multilevel that we have now)... \- rail
constructors (rails for welders/material suppliers to move along)

~~~
oldgregg
Spiders are a fascinating if not slightly scary concept. I would if current
construction methods would have to be simplified in order to reduce errors.

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something
maybe you are underestimating the extent to which this is already done? there
are machines that eat steel and glass and produce windows and structural
elements (wires, carpets, tiles, lightbulbs...)

the economies of scale come from not lugging these machines to every job site.

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notaddicted
I think that the cost of human labor is <10% of the cost of materials, so it
would not make much of a difference.

I wish I could find some numbers for some recent projects, I haven't got
anything to back this up.

