Contour Crafting - Extrude-a-House

lww writes "An article in New Scientist discusses the work of Behrokh Khoshnevis at the University of Southern California to design and build a fully automated robot that performs Contour Crafting, his name for a process to extrude successive layers of semi-fluid building mixtures like concrete to create entire structures. In the article, he says 'The goal is to be able to completely construct a one-story, 2000-square foot home on site, in one day and without using human hands.' by 2005. I'm pretty jazzed at the potential to construct buildings with highly curved/creative contours that would be impossible using current construction techniques."

Comments

Matt Helm strikes again

[AtariAmarok]

Matt Helm did this in 1967 in his movie with an inflatable bedroom.

Oh yeah

[mskfisher]

Slashdotted.

Fortunately, I downloaded the movies and made a BitTorrent version available:

http://www.mskf.org/contourcrafting.torrent

Enjoy.

Re:Oh yeah

[mskfisher]

And now, because my bandwidth limit hasn't been touched this month, I provide you with a mirror of the USC page:

http://www.mskf.org/mirror/contour/

w00t.

Not necessarily...

[Anonymous Coward]

As with current construction methods, if you have, say masonry construction, you typically specify a masonry opening dimension for the contractor to build to (which is approximately the size of your opening), and any extra space is just shimmed out. A bit of shim, maybe some backer rod and sealant, and you're gold.

One possible problem that I can see offhand would be expansion/contraction cracks. Would the robot create construction joints every few feet to allow for said expansion/contraction?

Re:One day?

[AlecC]

True. Throwing up the brickwork is one of the fastest parts of building. Usually laying in the site services and getting good foundations down take an age, then the shell appears in a trice, then fitting oudt take another age.

I can see the machine itself being installed quickly - after its track has been carefully laid.

The interesting bit, as the original /. post said, is the possibility to build in wierd shapes. However., after reading How Buildings Learn,, it seems thst this is not generally a good idea for long term use use of buildings. Square may be a bit, erm, square, but it is much more adapatable - and successful buildings are above all adaptable.

Greg Lynn

[mieses]

quoting from the article:
"Greg Lynn, a leading architect from Venice, California, said. "I believe that aesthetically there's a great potential to make things that have never been seen before."

Look at Lynn's site [Flash plugin required] to see examples of the kind of forms that might be possible with this process.

windows are easy, but what about...

[Intraloper]

For windows and doors, even in a curved surface, you justspecify a flat flange to install them to. Still have to install them, though. Also the interior door. But what about foundations? Still gotta dig the hole and fill it with something heavy, rigid and stable. How do you tie it down to the foundation? Tie rods? You would still need rebar in the structure itself to attach the tie rods to. Here in California (and a lot of other places), you also need sufficient reinforcing in the structure itself to handle seismic loads, and those have to be connected via rods or bolts to the foundation. What about wiring and plumbing? They are typically enclosed inside the walls, for safety and aesthetics. How do you imbed a complete wiring and plumbing system into the walls? Perhaps you could program the machine to actually form the waste piping, but you still need a water supply. Chases in the structure? Then you have the issue of pulling piping and wiring through a complex system of chases. Ventilation, heat and cooling? Same issues. This looks potentially cool, but building the structure is only one small part of building a house, and saving some money there doesnt necessarilly save you anything on the entire structure.

Re:Plumbing, electric, etc

[og_sh0x]

If you go to the technical paper, take a look at figures 5 and 8. Now a quote from page 3 of the same paper: Utility Conduits: As shown in Figure 5 utility conduits may be built into the walls of a building structure precisely as dictated by the CAD data. Sample sections made with CC and filled with concrete as shown in Figure 8 demonstrate this possibility.

Re:Plumbing, electric, etc

[Anm]

Patent Pending. I'm serious. These guys have already thought of and nearly solved the piping and electrical infrastructure problems. But just haven't publicly unveiled it. I sat in on a talk here at USC by Dr. Khoshnevis.

The bureaucratics issue came up also. That one is going to be very tough. In the mean time, his applied focus is on adobe house construction in rural areas and third worlds. Oh yeah, and extraterrestial buildings (assuming we can make mud on Mars/Moon).

Anm

There are already versions of this out there

[Walter Wart]

A while back, when we were considering building a house and some specialty buildings, we looked into a number concrete technologies. Some of them have been out there for over twenty years and would be competitive in terms of labor and material costs as well as flexibility. The idea is cool, but it isn't necessarily an improvement.

Some of the technologies are:

1. Gunnite and Shotcrete Starting with a disposable "frame" and your rebar you spray successive layers of concrete and gradually build up the surface you want. This is pretty much the same as the robot in the article but with human operators. A good friend of mine used this to make all the rock work at the Portland Oregon zoo more than twenty years ago.
   
2. Liteforms and its successors There Insulation and modular forms in one package. The original version of this was big essentially styrofoam panels that served as forms for a normal concrete pour. Later products are more like hollow Legos. You set up your first course and then just build it up putting in rebar and your desired conduits as you go. We saw one man and two teenagers do a very complicated 4000+ square foot basement with curves and strange angles. It took them a weekend from laying it out to the actual concrete pour.
   
3. Building Blocks A German company whose name escapes me makes a sort of foamed concrete masonry block. Less than half the weight and more than 80% of the structural strength of regular concrete. It's put together with mortar and can be cut with a Sawzall (with the right blade). Unfortunately they have been very conservative about finding new uses and marketing for this product.
   

The styrofoam forms have the advantages of also being their own (very high R-value) insulation. You get the further advantages of a single monolithic pour for the who building. The walls have to be vertical, but that is something that the magic 80% of people would want anyway.

Gunnite and shotcrete can be used for the curved ceilings and hobbit-hole style walls if that's what you want.

So my gut feeling is that it's a really cool hack, but the alternatives will probably be cheaper quite a while to come. Also, a big part of real construction is reconciling the architect's drawing with reality. Things change on a job. The site isn't exactly what needs to be, even with good site prep. There are change orders. Or the concrete pumping company has decided to strengthen its bottom line by selling you product that has too much water. Or things aren't quite working right and have to be corrected on the fly.

Turning the robot on and letting it go probably works better in the lab than on the job site.

Great Idea - However it was Developed in 1960's

[Coorain]

Somewhere in my stack of architecture design articles is a paper from the 1960's that describes an automated extrusion process to build homes and other structures. The idea involved a robotic arm controling an extrusion device that assembled layers to produce walls, floors etc.

One immediate application was the construction of very large insulated dome lids for sewage treatment plants.

If anyone is interested in the details I will try and find the original article, scan and post it here.