I'm curious how they are bridging the gaps for windows and doors. I imagine toothpaste consistency concrete doesn't hang in the air very well. Or at least not nearly as well as thin, hot, stringy PLA, ABS or TPU filament coming out of the nozzle of a common 3d printer.
Right, I've done this with auto generated supports in Cura for PLA and ABS fused deposition printing. Removed with needle nose pliers. But if done with semi liquid concrete wouldn't it cure together and become very difficult to break apart ?
Looking at the photos of the houses, I wonder if they pause the printer at the point just before where it needs to draw the first layer above the top of the window frame. At that point a couple of workers manually lift the prefab window unit into place. Then the printer can resume and print that next layer on top of the top of the window frame.
That said, wooden and, more recently, foam forms have been used since forever. (At least a hundred years?) Breaking the forms away from cured concrete doesn't seem to be problematic.
EDIT: Also, in another video there's a brief shot where the machine is printing the internal zig-zag pattern over a steel mesh manually placed on the wall, presumably for reinforcement. I fast-forwarded through 4 or 5 videos and it's almost suspicious the way they avoid capturing these details. I guess such details don't fit the narrative they're selling.
They really show only very brief glimpses of the actual printing process. Not even 1/100th of the linear extruded length of a single layer before the video cuts to something different.
Personally I think they should emphasize the manual labor requirements. One of the strongest criticisms of 3D-printed and prefab housing technology is that it reduces demand for low-skilled labor. For the past 80 years home construction has been a major pillar of the American labor economy; likewise for China and many other countries. Free or reduced cost housing is great, but to the extent it comes at the expense of a sustainable labor economy, then it's problematic.
The openings look "U" shaped, and filled with the window frame and topped with vent tiles. It doesn't look like any support is needed as those are probably added after the print dries.
From glimpses in photos & videos it looks like humans are involved at various stages of production, including putting metal plates across the gaps for doors & windows.
Really interesting idea and potentially a great benefit. I do find it funny that they decorated the house in a very American/European style. That works great for press photos aimed at US investors, but I wonder how all that will fare given the high traffic & use that occur in small dwellings.
How is this cheaper than shipping in prefab blocks and bolting them together? There are lots of claims about it being low cost and affordable but little data to explain why.
Well, a manufactured home in the US can be quite affordable. Of course, in "many locations" (oh gaw, I'm in California) permitting, utility hook-ups, land and so-forth adds so much that the cost of just assembling the physical house isn't that important.
Of course, this is Mexico, so I assume the equation is different. But in Mexico, at least they'll let you live in a shack-I-mean-tiny-house, so I assume this has to be somewhat competitive.
I find it hard to believe it is, frankly, particularly when you take into account the highly specialised equipment and apparently a large rain shield that need to be setup beforehand. Less trendy modern methods of construction can deliver things like fully-fitted bathrooms to sites.
I'd have thought the virtues of 3D printing as a construction technique are much more to do with precision forming of unusual shapes tbh, which is the other end of the market.
Probably not cheaper yet. But it could be logistically simpler. The whole thing would fit on a truck, source local concrete and you're basically done with the frame. Windows/doors/mechanicals/finishes still need solved for of course.
Seems like they are just doing R&D at this point though.
This here is low cost and affordable: https://en.m.wikipedia.org/wiki/Plattenbau Almost 100 years ago Germans discovered the way of cheap building. The first houses are still used according recent documentary. This 3D printing might be novel, but basically they move their factory each time for a new house while Plattenbau factory must be installed once. Plus Plattenbau has canals for cables and already installed windows and doors. Plus Plattenbau can be a high building. I live in one from 1965, it’s really shitty. Insulation between concrete layers is gone, you can hear TV of the neighbors and it’s cold in winter.
Prefab cross-laminated timber (CLT) is a modern equivalent. It is suitable for highrise buildings (no concrete, all wood including elevator shafts, etc) and it is a carbon sink for as long as the housing stands.
How about taking the best of both worlds? Move the printer relatively nearby (it could be on a boat, for instance), and have it print prefab items on demand; those can have complex and one-off shapes as well.
You likely make it cheaper by using locally-sourced materials (gravel, sand, cement if possible) instead of transporting those. And you can probably pack the rest a lot more tightly than moving those air-filled walls around.
Any information on how soundproof these houses are? What is the expected lifetime? Maintenance costs compared to traditional houses? How difficult is it to repair the walls with traditional materials?
I think this will vary greatly by region. In places where lumber is cheap and plentiful we have the typical American stick built house.
But it would be difficult to find a house in Rawalpindi, Pakistan that isn't composed from some combination of locally made small bricks, concrete blocks, concrete and cement.
I know a number of people that had never seen drywall, the building material, before immigrating to north america.
One reason people make houses out of brick/concrete in poorer regions, is that there are many people living in the same house. And wood houses are terrible at being soundproof, while brick/concrete houses are great at it.
Only in North America have I been told that I woke someone up in the middle of the night because I opened a door or got a glass of water from across the house because the house creaks and drums when you walk across it.
Many American houses indeed have terrible sound-proofing. But placing a higher value on that surely isn't why people in poor countries build of concrete blocks. Wood is plentiful in the US, and labor is expensive, this is mostly what drives the difference.
This seems to be the default low cost construction option the world over. I've seen this all over asia as well. I've had a (second) house built that way and it generally works fine (and looks fine with some plaster on it as well). The only thing is the insulation is atrocious, but that matters less in the right climate.
It's fairly popular in Germany as well, where insulation requirements are quite high. But since you have to add insulation to nearly any building material you can just as well build with concrete bricks and slap polyurethane boards on the outside (or whatever foam boards you use nowadays for that job) and then plaster over that.
My house is also built from concrete blocks, because they have quite good parameters when combined with good thermal insulation. Concrete walls were something like 3% of price of the house and they were done in a week, that is again something like 5% of (my) house construction time.
Concrete blocks can be produced locally with rather simple tools. It also has benefit that it may provide work to local people.
In poor regions, labor is cheap and creating workplaces is always benefit to local commnunity, so I wonder if automating this out is positive thing at all.
I'd like to see comparison of costs/benefits for houses built like this vs more traditional construction. Don't get me wrong, I love tech toys, but this looks very much as a solution looking for a problem.
Yes exactly. This seems to be replacing the part that was never a problem (building walls) with something high-tech and surely expensive.
The nozzle that deposits that concrete is just guaranteed to be much more fussy about quality control than the guys shoving it into moulds to make blocks. So it'll need high-quality materials transported from somewhere, not whatever is lying around.
I agree, this would make much more sense in areas with high labor costs, something like sea side resorts where you can produce many similar buildings with high building density.
Neat, though I'm a bit skeptical about its utility outside of rural areas. Particularly in the US, the problem with housing affordability is mostly in booming metros where people want to live in already developed areas, the most expensive part is often the land, instead of the house, so you really need density/verticality to make a dent in affordability.
Cool. But completely not a solution to affordable housing construction in rural areas.
What is the barrier to affordable housing construction in rural areas? Where I traveled in Uganda it was availability and affordability of materials and equipment. Cement was expensive as was corrugated roofing. Renting heavy equipment was expensive.
We had plentiful cheap unskilled labour, free bricks made from clay soil baked in the sun, lots of hand tools and a foreman with basic construction skills. Transportation was slow but not prohibitively expensive.
I hope this 3D printing technique is simply a way of waving a flag to draw attention to the need for better housing in these communities. There are many much better MVPs than an expensive machine using expensive materials operated by an expensive team.
I have a trite observation, but I think it has merit: Minecraft shows that the cheapest building material will always be that which is nearby.
For this solution to scale, it has to be really good at dealing with whatever's available. This seems exactly the kind of "making square pegs fit round holes" problem that is suited far more to localized human ingenuity than automation.
In Uganda, it is legal to use cheap construction methods, like wattle-and-daub using cow dung, and thatch roofing.
Appropriate technology there is a hand-press for making TIB-style mortarless interlocking bricks from local dirt. (I have heard that Ugandan brick masons use way too much mortar anyway.)
The test site was likely in Mexico because building codes in the US have no provision for establishment and testing of new technology that is too far removed from existing construction techniques, such as inflation forms lined with rebar and sprayed with shotcrete, or 3D-printed corrugated-interior concrete walls. If the machine built 50 houses in the US, none of them could get certificates of occupancy from the inspectors.
The end goal is likely not to house the poor around the world, but to establish building codes that advantage the first-movers in printed-concrete home construction, so the patent-holders can build houses in the US that can be finish-ready for $5000, install windows, doors, electrical, and plumbing with assembly-line labor, and then sell for $75000.
If the machine built 50 houses in the US, none of them could get certificates of occupancy from the inspectors.
I agree with your concerns over the way regulation gets us stuck in a rut. But from TFA:
"The same technology could also help transform the construction of affordable housing in the United States. Earlier this year, Icon printed a welcome center for a master-planned community in Austin, Texas, designed for people who have been chronically homeless, and the company is beginning to print 400-square-foot homes in the community that will be completed in early 2020."
In most states you need a professional engineer to certify that your odd construction is safe. This pulls in legal liability for failure so the engineer will charge a lot of money (and run a lot of calculations) before granting certification. It isn't a big deal to do that if you can figure out how to pay the cost.
By contrast though: I can design you a house that follows traditional design rules. So long as I use standard materials under the standard rules someone else has long ago done all the work to ensure the standard is right and so it doesn't need additional certification. It is quite likely I can violate something in the standard and still be safe - but then it is up to me to prove it is safe (I'm not qualified to do this)
Wouldn’t there be economies of scale here though? Presumably the first print would be very expensive from certification standpoint, but wouldn’t the marginal cost going forward be negligible?
Maybe, it depends. If you build exactly the same house on exactly the same soil type. However every change needs to be re-certified - you can get around this of course, the engineer can decide what changes you are allowed to make.
Houses get around this because engineers figured out the limits - a 2x12 can up to (note up to not exactly!) span x distance under these assumptions. The inspector just verifies you met all the conditions and you are good. You can do this with any form of building, but it is much cheaper for one building to just certify that exact design. If you only have a half dozen designs it is probably cheaper to certify each separately, but eventually you have enough different designs that you just figure out the limits and rules and never have to worry about it again.
If you can get the building inspectors to accept the engineer certification from another building of similar construction.
You might be able to do that on a single property with 50 identical copies of one design, but one at a time is unlikely. So you build the engineer certified designs and then lobby to get the method of construction included in the building codes.
"The printer works by squirting a concrete mixture in layers to build floors and walls."
Is that one a special type of concrete? In places where earthquakes occur I would expect some kind of reinforcement to that concrete mixture, or it would crumble very easily at the first hit, but from the article it doesn't seem they're adding iron bars or any similar reinforcement.
I don't want to downplay the good work they do but I can't stop thinking that these people are guinea pigs for the technology. Now, considering their initial housing they can't really complain.
This clearly makes no sense.... but I'd like to see it go on.
I think since donors have to feel good about themselves they won't just donate concrete and bricks.
And since NGO's can't build houses that are not up to code they can't just use local labour.
So this might work.
Earthship houses have shown after decades of having a cheap house design with cheap materials, that's not enough to solve the problem. Watch the docos read between the lines.
The actual benefit here might even be the fact the NGO makes the government give land titles for under the houses.
They seem like such simple structures. I could build one of those out of rammed earth or cob in the time it takes to put up the rain shield. Cheap housing (especially in rural areas) is a solved problem. Cheap, legal, socially acceptable, housing is not.
I looked into this a few years ago. I discovered that even if I can build the 3d printer myself for free (including time), wood structures are still cheaper than the concrete. The only reason you would choose this over something else is if you want a unique shape that is impossible to do in wood. I wanted to build a cheap shed, but this was one of the more expensive options, and it didn't really save any labor either.
A lot questions about cost, but nobody is talking about speed. They said the frame was both fabricated and erected in 24 hours. That's a big one-up on prefab.
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[ 3.6 ms ] story [ 130 ms ] threadhttps://m.all3dp.com/2/cura-support-settings-optimize-your-s...
Looking at the photos of the houses, I wonder if they pause the printer at the point just before where it needs to draw the first layer above the top of the window frame. At that point a couple of workers manually lift the prefab window unit into place. Then the printer can resume and print that next layer on top of the top of the window frame.
That said, wooden and, more recently, foam forms have been used since forever. (At least a hundred years?) Breaking the forms away from cured concrete doesn't seem to be problematic.
EDIT: Also, in another video there's a brief shot where the machine is printing the internal zig-zag pattern over a steel mesh manually placed on the wall, presumably for reinforcement. I fast-forwarded through 4 or 5 videos and it's almost suspicious the way they avoid capturing these details. I guess such details don't fit the narrative they're selling.
There's got to be something in there that supports horizontal forces.
Personally I think they should emphasize the manual labor requirements. One of the strongest criticisms of 3D-printed and prefab housing technology is that it reduces demand for low-skilled labor. For the past 80 years home construction has been a major pillar of the American labor economy; likewise for China and many other countries. Free or reduced cost housing is great, but to the extent it comes at the expense of a sustainable labor economy, then it's problematic.
Of course, this is Mexico, so I assume the equation is different. But in Mexico, at least they'll let you live in a shack-I-mean-tiny-house, so I assume this has to be somewhat competitive.
The possibility of using local materials for a 3d printer is enticing, however.
I'd have thought the virtues of 3D printing as a construction technique are much more to do with precision forming of unusual shapes tbh, which is the other end of the market.
Seems like they are just doing R&D at this point though.
You likely make it cheaper by using locally-sourced materials (gravel, sand, cement if possible) instead of transporting those. And you can probably pack the rest a lot more tightly than moving those air-filled walls around.
Edit: Waterproof? Earthquake proof?
https://s3-us-west-1.amazonaws.com/contentlab.studiod/getty/...
But it would be difficult to find a house in Rawalpindi, Pakistan that isn't composed from some combination of locally made small bricks, concrete blocks, concrete and cement.
I know a number of people that had never seen drywall, the building material, before immigrating to north america.
Only in North America have I been told that I woke someone up in the middle of the night because I opened a door or got a glass of water from across the house because the house creaks and drums when you walk across it.
Concrete blocks can be produced locally with rather simple tools. It also has benefit that it may provide work to local people. In poor regions, labor is cheap and creating workplaces is always benefit to local commnunity, so I wonder if automating this out is positive thing at all. I'd like to see comparison of costs/benefits for houses built like this vs more traditional construction. Don't get me wrong, I love tech toys, but this looks very much as a solution looking for a problem.
The nozzle that deposits that concrete is just guaranteed to be much more fussy about quality control than the guys shoving it into moulds to make blocks. So it'll need high-quality materials transported from somewhere, not whatever is lying around.
This page mentions $15/sq-ft, and declining, so a 500 sq ft home would be $7500. Or 100 months of average income in this part of Mexico.
What is the barrier to affordable housing construction in rural areas? Where I traveled in Uganda it was availability and affordability of materials and equipment. Cement was expensive as was corrugated roofing. Renting heavy equipment was expensive.
We had plentiful cheap unskilled labour, free bricks made from clay soil baked in the sun, lots of hand tools and a foreman with basic construction skills. Transportation was slow but not prohibitively expensive.
I hope this 3D printing technique is simply a way of waving a flag to draw attention to the need for better housing in these communities. There are many much better MVPs than an expensive machine using expensive materials operated by an expensive team.
For this solution to scale, it has to be really good at dealing with whatever's available. This seems exactly the kind of "making square pegs fit round holes" problem that is suited far more to localized human ingenuity than automation.
Appropriate technology there is a hand-press for making TIB-style mortarless interlocking bricks from local dirt. (I have heard that Ugandan brick masons use way too much mortar anyway.)
The test site was likely in Mexico because building codes in the US have no provision for establishment and testing of new technology that is too far removed from existing construction techniques, such as inflation forms lined with rebar and sprayed with shotcrete, or 3D-printed corrugated-interior concrete walls. If the machine built 50 houses in the US, none of them could get certificates of occupancy from the inspectors.
The end goal is likely not to house the poor around the world, but to establish building codes that advantage the first-movers in printed-concrete home construction, so the patent-holders can build houses in the US that can be finish-ready for $5000, install windows, doors, electrical, and plumbing with assembly-line labor, and then sell for $75000.
I agree with your concerns over the way regulation gets us stuck in a rut. But from TFA:
"The same technology could also help transform the construction of affordable housing in the United States. Earlier this year, Icon printed a welcome center for a master-planned community in Austin, Texas, designed for people who have been chronically homeless, and the company is beginning to print 400-square-foot homes in the community that will be completed in early 2020."
By contrast though: I can design you a house that follows traditional design rules. So long as I use standard materials under the standard rules someone else has long ago done all the work to ensure the standard is right and so it doesn't need additional certification. It is quite likely I can violate something in the standard and still be safe - but then it is up to me to prove it is safe (I'm not qualified to do this)
Houses get around this because engineers figured out the limits - a 2x12 can up to (note up to not exactly!) span x distance under these assumptions. The inspector just verifies you met all the conditions and you are good. You can do this with any form of building, but it is much cheaper for one building to just certify that exact design. If you only have a half dozen designs it is probably cheaper to certify each separately, but eventually you have enough different designs that you just figure out the limits and rules and never have to worry about it again.
You might be able to do that on a single property with 50 identical copies of one design, but one at a time is unlikely. So you build the engineer certified designs and then lobby to get the method of construction included in the building codes.
Is that one a special type of concrete? In places where earthquakes occur I would expect some kind of reinforcement to that concrete mixture, or it would crumble very easily at the first hit, but from the article it doesn't seem they're adding iron bars or any similar reinforcement.
I think since donors have to feel good about themselves they won't just donate concrete and bricks.
And since NGO's can't build houses that are not up to code they can't just use local labour.
So this might work.
Earthship houses have shown after decades of having a cheap house design with cheap materials, that's not enough to solve the problem. Watch the docos read between the lines.
The actual benefit here might even be the fact the NGO makes the government give land titles for under the houses.