Iowa Demolishes Its First 3D Printed House

It sounds like a headline from the future: the weekend before Thanksgiving, a bulldozer came for the first example of a printed home that was supposed to help the housing crisis in the city of Muscatine. Fortunately, it hadn’t been completed and sold yet.

Printing of this first house began in May 2023, and nine more were to be completed by the end of the year. Unfortunately, when tested for compressive strength, the cement mixture this first home was printed out of failed to meet the 5,000 PSI minimum required for the project. Rather than compromise on safety, the parties involved decided to knock it down and start over.

The goal now is to find out why the mixture, which met the strength requirements in laboratory testing, didn’t behave the same on-site. Currently, the plan is to start building the originally-planned second house in the spring, and begin construction on this first site after that.

The project is a collaborative effort between the Community Federation of Greater Muscatine (CFGM), Muscatine Community College, and Alquist 3D. Want to know more about the state of 3D printing when it comes to housing? Check out our handy guide.

Editors Note: The initial post initially indicated that the failed cement mixture contained hemp, but that has since found to be incorrect and the post has been edited accordingly.

130 thoughts on “Iowa Demolishes Its First 3D Printed House

    1. The walls appear to be being printed with a large cavity (see seond picture) which I would guess is intended to be filled after curing. I assume that they are dropping wall-ties in occasionally, but I don’t see any.

      I doubt it is any faster than a couple of builders throwing up insulated blocks and a brick skin in the European pattern, though. And it is possibly more weather-limited (but less daylight-limited)

      Building a boring box seems like a waste of the technology, I want to live in a Yoda head.

      1. It’s likely less expensive at-acale without all of the relevant tradesmen being involved.

        Although it’s not clear if they are running utilities in the void or not….

        Just skip the hemp and do regular lime-and-rocks concrete

        1. That’s not true at all. You can erect and pour a solid concrete foundation in less than a half a day, that stupid house started in May and still didn’t finish the foundation.

          There is no cost savings when the house takes a year to build.

          1. Let’s be realistic. When the reprap movement first started, the mendel was the first model and the prints it created were slow, and they looked awful. Honestly, skilled artisans could build the target objects by hand in less time and cheaper. Look where we are now…we have printers that can produce amazing results, in a fraction of the time, with large build volumes.

            The point isn’t to be completely competitive tomorrow. The point is to keep improving until one day it *is* competitive. Hell, 3D printing has gotten so good we are getting in range of hobby desktop metal sintering.

          2. I sort of agree. I think the whole point of 3d printing in general is to make Geometry that would otherwise take a very long time to erect take a reasonable amount of time. I’ve seen 3d printed houses that used this to it’s advantage, and ones that just felt like a gimmicky way to cut cost

        2. Spot on. This looks like proof of concept for investors and municipal inspectors. A house or a subdivision should have more reasonable times. If tracks where laid down and 10 perfectly engineered models where created I’d expect them all done with pre-installs for utilities in pretty much a single year.
          Material costs are the second most expensive part of a house…it’s the labour that has most of the cost before finishes are involved.
          Yes, foundations or slabs are a big deal and not typically a 3D activity. And also yes insulation in all its options are important depending on location. But they also exist in conventional builds and don’t comprise a lot of time or relative cost.
          Printing homes can provide housing for the poor, rebuild hotels in disaster sites and provide unique home designs for those willing to pay for them. It’s just another innovative building method and it will need to have some great victories to win over the resistance to change and the displacement of labour.

        3. Factory-built houses that turn up on site in sections and get screwed together are very efficient and super fast, if you’ve ever watched the TV series “Grand Designs” it’s not uncommon for a house to go from foundation to full height in a few days.

          You can have all the machines and automation in a nice warm dry factory with none of the problems of a muddy building site, as well as warm dry workers who can pre-wire and plumb and insulate and even glaze the panels before they get loaded on a truck and stood up on site by a few guys with a crane and a nail gun.

        1. Developers don’t care about “better”. I’ll refer you to the Project Management Triangle: Good, Fast, Cheap – you can pick only two of the three. If you choose fast & cheap, it will come at the expense of quality.

      2. The problem with the build was Iowa wanting their hemp included. Where standard materials are used there is no issue. I think they are not very appealing, but they are being used in 2 ways. If you take a nice flat treeless parcel you can print out a hundred or so in a couple of weeks. The builders are doing this for low income properties, and make nothing in profits. As a result of their exposure wealthier people are ordering highly customized homes, sometimes going into millions of dollars. They can make you a Yoda Head House. I do believe there is tremendous upside to printed houses.

      3. They are laying re-bar throughout the construction of the walls. I was curious how this project would work through notorious and ever changing Iowa weather especially the 112% humidity days.

    2. Hemp has stronger insulating abilities than traditional concrete and some people are using it instead of traditional insulation. It as also ironically naturally more naturally fire retardant than wood. It is not currently cheaper than wood, but investing in hemp based infrastructure will in the long run save money and sequester carbon. On major issue is while there is a plethora of people growing hemp for cbd oil, and thc where it’s legal. There are not enough people growing hemp for fiber, and not enough infrastructure for processing said fibers.

      Hemp is not a cure all. There will always be a place for traditional concrete, steel and even lumber based construction, but it is absolutely better for the environment.

        1. A quote from

          Fire is, of course, the first concern that comes to mind with wood construction – there’s no denying that wood burns. And yet, there’s a great deal of evidence to suggest mass timber is actually safer in a fire than steel.

          For example, in a fire, a thick plank of wood will char on the outside, sealing the interior and protecting it from damage. Wood burns slowly at approximately 0.02 inches/minute and the char created on the wood surface as it burns helps protect and insulate the unburnt wood below and maintain the structure.

          This is because the build-up of carbon on the surface will limit the oxygen supply to the wood below and act as insulator. Therefore, the wood below the charred level will be cool and retain 85 to 90 per cent of its structural integrity.

          Metal, on the other hand, begins to melt when it reaches a critical temperature (around 1300 degrees C) so will fail catastrophically

          1. Never have I ever had such a strong urge to say “look at the source” – that’s a wood merchant trying to say that steel “just melts at a mere 1300C”, when wood is alight and self sustaining combustion at below 450C. Indeed, wood alone *cannot* burn hot enough to melt steel! You need to make charcoal and then force air to even get close. Even the biggest bonfire tops out at 1100C.

          2. The fact of it is that metal softens at far less than the melting temperature.

            You don’t have to melt steel for a steel structured building to collapse. You just have to heat it enough that the steel begins to bend under the load.

          3. NKT:
            Yet you accept Wills assertion about hemp’s ‘naturally more naturally fire retardant’ without similar comment.

            Which is fair, he gives no source, just ‘dark smelly place’.

          4. “For example, in a fire, a thick plank of wood will char on the outside, sealing the interior and protecting it from damage.”

            Some fire retardant paints work the same way. With heat they expand, creating a porous material that carbonizes and isolates the metal from the flame. But this only serves to save time. In the event of a fire, the objective is to save time to evacuate people, goods and get aid.
            An old house with wooden structural elements may burn slower than a modern house built with concrete, steel and aluminum. The use of synthetic materials obtained from petroleum can also accelerate the combustion process and produce highly toxic fumes. For this reason, firefighters are prohibited from entering buildings with this type of insulation in some countries, and can only fight the fire outside.

      1. Nobody anywhere is growing hemp for THC. See definition of hemp in the USA.

        There might be some grown for legit CBD oil, but that space is full of scams. Hemp oil is not CBD oil.

        Hemp for fiber is pretty well optimized and modern overseas. Rope.
        Hemp for clothes is for _rich_ smelly hippies. Cotton his just better and cheaper.

        If you grow a hemp for fiber crop, you are wrecking every sensi crop for miles.
        There are even assholes growing patches of males because they are butthurt over legalization.
        Fortunately, not near me. That would get your ass kicked in this CA neighborhood. Nobody would have seen nothing. Many different boot size marks on head. Hemp bale surgically removed from body cavity.

      2. Why is hemp the magic ingredient? What about other biomaterials such as corn stalks or wheat stalks that are already part of ag production without a great use. Why would a biomaterial improve the inorganic properties of cement anyway? Seems to me that it adds an element subject to weathering and decay which is a major disadvantage to wood over masonary construction. Insulation would not seem to be it since the material is encased by traditional concrete.

        1. Hemp is an excuse to get subsidized to fail.

          Usually when people ask why we aren’t doing X anymore, the answer is “because it’s worse than what we have now”. Hemp fiber has this status and a plausible excuse as a “suppressed technology” that attracts investors and public funding because of the underdog status, because of how “unfairly” hemp has been treated because of the war on drugs. Projects get funded, nothing comes out of them, investors back off, then everyone forgets and a few years later the whole thing repeats.

          In reality of course, Manila hemp, sisal, etc. overtook hemp hemp as a source of rope fiber even back in the day when hemp was still being used, because they were cheaper and better. Then synthetic fibers beat all the natural fibers and the rest is history.

          1. This is the first time I’ve seen someone else state the truth about the history of hemp. I highly encourage any industrial hemp enthusiast to look up the rise and fall of Matt Rens, America’s Hemp King during World War 2. Everything you said is 100% true and happened in the 50s, years before the Controlled Substances Act. It’s not “suppressed technology” and has been importable since the 90s. As a professional in the industry, I can tell you that hemp fiber is not going to catch on.

      3. “Sequester carbon”

        You parrot the big lie. Carbon is life-giving. Cheap, abundant, efficient. Improves the standard of living for the entire world. Does ZERO to harm it. I’m all for research and development of better building materials that are even less expensive, more abundant, more efficient. Whether that’s found in carbon, hemp or any material, I have zero preference. To base decisions on “carbon sequestration” or any other fantasy that man controls the earths climate is beyond idiotic. And the result of a completely programmed, propagandized, menticided mind. Good luck with that.

      4. How do you “sequester carbon?” When the ENTIRE PLANET is made out of…..CARBON! This is another stupid liberal educated, dimwitted, environmentalist idea that is simply a fantasy. Also, hempcrete when done right, holds up for centuries. There are a ton of buildings throughout Europe w
        built with it that are older than our country and look brand new. These guys just havent figured out the recipe yet. “Carbon seguestering” what a joke.

    3. Zoe, what is wood?
      There is a lot one can pick up from deconstructing a structure.
      What we might be trying to understand is what do new materials perform like compared to what exists now.
      It’s about producing progress in construction materials & technology.

    4. Truly extraordinary how many nerds will chime in with criticisms of an experimental project based on [checks notes] no information. You think they haven’t thought of insulation? Have you ever been to Iowa? I assure you, insulation has been worked out. Good grief people. If you don’t know what you’re talking about, don’t forget you could always just say nothing.

    5. Hempcrete is naturally insulated as there are air pockets in the hemp Hurd. However, if this community college actually did their research and provided real reports they would note that hempcrete cannot self support. This is a failure of engineering.

    6. I designed, tested, and poured structural and architectural concrete mixes in the western states for 30 years. No plant based product could do what cement does. If they they tested mixes with a mix of cement and the hemp product they would see more reliability in 28 day strength.

    7. I actually visited the site and the project. After talking to everyone I could that was involved in the project, (because I’m going to build a 3D home in ’24) I found that: 1) they were advised by the scientists who created the material, to include an expansion joint every 10′ or 12’… the crew and the local architect and engineers did not follow this advice, 2) 5000 psi is not required in other 3D projects, but the City of Muscatine decided they wanted that strength in this project. Speaking with other cement experts, they thought 5000 psi was a little over-the-top, 3) It was recommended to the architect to build the first house WITHOUT printing over the tops of doors and windows (most use floor-to-ceiling doors and windows to avoid this)

      I’m simply pointing out some of the other chapters in this story that aren’t present. The truth is always somewhere in the middle.

      1. You don’t have to live in a peanut fueled diesel engine. This project was targeting low income housing. These people may not have much of a choice in where they live so we shouldn’t build them out of things people have strong reactions to.

    1. Where I live, it’s customary to cover the interior of living surfaces with a collection of drywall, paint, tile, carpet, vinyl and other materials which would make exposure to this extremely rare allergen less likely to create an issue.

      1. All those “conventional” products emit toxic VOCs (volatile oil compounds). That new house smell, and the smell of fresh paint, are VOCs that are toxic and that we take for granted as necessary to building. A properly built industrial hemp house (not a THC vapor to be had) with lime plaster walls is the most healthy construction material humans have so far invented.

    2. A quick search of the literature suggests that your claim is not evidence based, i.e. please cite a reputable study that indicated that industrial hemp fiber is a significant allergen. I don’t care if I am right or wrong, I only care about gaining useful knowledge. I’ll wait…

    3. I don’t think the allergies would be a problem. If one were allergic to nails, and there are plenty of those in a house, I don’t think one would get a reaction to the nails in the house framing once the drywall, mud and tape, and paint were added. Consider the hemp to be equally if not more buried in the constructions systems than the nails are.

  1. I think the value proposition for 3D printed homes will require the killer app. That is what features of a printed house does it enable in a better way than traditional homes. I’m not sure what those might be. Architectural whimsy like frank geary seems possible. Another might be making housing development in which every home was a different shape rather than cookie cutter. Perhaps the crews needed are smaller simplifying the contractors need to make payrolls. Perhaps it allows additions to houses easier so that one can start with a small house and grow it over time. Perhaps fire safety in times of forest fires and electric vehicles will favor concrete homes.

  2. I’m glad they’re going back at it to try again. Too many folks give up after a first failure instead of learning from it. Its a good look for the city too since they didn’t compromise on their standards to make an affordable housing project look good.

    A good object lesson is San Diego. The city speed built several full sized homes in under six hours, one took less than 3, by prestaging all the contractors and materials needed to get it done. It was a publicity stunt to advertise the city’s construction industry. Three years later the homes wouldn’t pass code inspections let alone one for a mortgage.

    I firmly believe 3D printed construction in the future, but like anything else new we just need to keep refining the tech.

    1. Why is this the future of home building? In which part is it better then traditional home building?

      Your lesson doesn’t even make sense to me. San Diego is famous for having extremely restrictive councils for approving construction. That hampers home building. They decided to instead have the city rush order some crappy homes rather then just letting people build homes. From that you conclude. Well sometimes bad ideas just need to be tried again and again eventually they will be good. Solar roadways are just around the corner an the hyperloop is the future of travel.

      1. > Why is this the future of home building?

        It’s not. It’s a steppingstone technology to something that doesn’t exist yet. You don’t get steam turbines without inventing the Hero engine first. This project has successfully identified an unknown unknown, that the experimental material does not have sufficient compression strength for the application. That sucks, but it’s progress. Once they have that sorted out I could see this technology being used today to print footers and foundations. Wood formwork is expensive, as are Bricklayers and concrete finishers. The companies doing excavation and site prep already have experience with heavy equipment; If they also offered a truck that would roll up to print the footers, foundation, concrete floors, and driveway I’d have a real hard time saying no to that. Cutting the number of subcontractors and site days required is a HUGE factor in how fast you can build a house.

        “But I want a 3-D printed house?” We’ll get there, but it probably won’t look like this. Concrete is expensive compared to stick framing and while this is “airtight, it isn’t well insulated. It’s a work in progress.

        1. Maybe.
          Maybe it’s just idiots applying the ‘latest thing’ to everything. (e.g. Putting your social life on a computer.)

          IMHO they’re answering the wrong question.
          The structure of a house is not the expensive or time consuming part.

          If the structure makes the plumbing, wiring, finish and maintenance harder, that structure is a bad idea.

          But enough about the Germans building _everything_ (kid’s tree houses) with poured in place ‘crete.
          It’s not that they’re proud of Heidelburg Castle (tourist trap), it’s that they can’t afford to tear it down.
          Same as Flaktowers.
          I digress.

      2. Concrete houses extruded layer by layer probably aren’t the future, but that doesn’t mean it won’t change the way things are built. Automatically placing heavy materials in a build-space the size of a house under a variety of real world site conditions is clearly useful. Learning the practical aspects of working on a jobsite with such machinery is also clearly useful. The applications aren’t limited to homebuilding either. If you had a complex segment of, say, a storm drain system, it might make sense to print on site rather than haul a large oddly shaped segment from a precast company or assemble/align massive molds with compound curves. Maybe you want to build something under 200m of water? A giant printer and the lessons learned printing bad houses could make doing something like that easier.

      1. Ah yes, the reflexive argument that any local/state/federal spending is equivalent to setting money on fire. *They* have multiple goals: training students, testing new building methods and material, and creating homes that teachers can afford to buy near their schools. You seem to think grants like this are just handed out on request. What kleptocracy are you living in to be so cynical?

          1. It doesn’t, it is far less expensive. Now this is for the mass development where they print out an entire subdivision. Individual homes printed out on a single lot can get into the millions of dollars. There is actually a waiting list to have these built. I suppose it’s like the guys that had to have the first electric vehicles. They are also highly customized for individual purposes.

        1. Training students: Fair enough. Failure will accelerate their cynicism. All good. Also note: CC in Iowa that has ‘hemp’ track. Stoners. Bet I could find some decent smoke at that school. Not as good as my home grown, but 20%.
          Testing new material? On a full size model? BS. Was kickbait. They _never_ had a plan to plumb or wire this thing.
          Affordable housing in Iowa? Have you ever been to Iowa? One thing it is: Affordable. This is BS.

          Grants handed out by request?
          Requires specially formatted request, only from people in club. Needs specialist to help write it. Keywords etc.
          Are you child?

          1. Are you a child or were you stoned when you wrote this? Your writing is borderline illiterate.

            So to summarize your comment. It started with you making irrelevant remarks that people at community colleges smoke weed, but that it probably isn’t as good as your home grown stuff, that’s an odd thing to brag about and try to one up college kids.

            Then some disbelief about them testing new material on a full size model. Yes people do that, especially when they are also testing the construction method at the same time. How do you know they never had a plan to plumb and wire it?

            So Iowa has no people that can’t afford to buy a house? Since the house prices are so affordable?

            Then comes the least understandable part of your comment. Do you really think all that is needed to get a grant is to be part of some club and get a specialist to write a request with keywords? Yes having connections helps, having a decent project helps and getting someone who knows how to file those requests helps but all of those are things that anyone trying to get funding for a project should be getting or should have anyway. Do you think they should just be giving grants to people who have no reputation or connections, don’t have a feasible project and just write the request any way they feel like? Maybe you should lay off your home grown weed.

  3. Learn from your mistakes and improve. Experience is the best teacher. And this is a very worthwhile research project! So the first iteration didn’t work out so well. It usually doesn’t on new ‘inventions’.

      1. This.
        Also hardens faster so maybe it “firms up” (higher “early” strength) in time so the next layer doesnt just squeeze previous layer out. If it has no reinforcing it would need to be stronger (as in psi) or thicker. 4000 psi is the level it is generally considered “waterproof” .
        I like the idea of the process, but putting anything in concrete that can rot (hemp, sawdust, etc.) turns from something that can last hundreds of years+ to something that wil likely deteriorate (less sustainable). May be ok in the desert?
        Not reaching spec strength can certainly be from contaminants but number 1 all time reason is someone adding water to soup it up so it pumps better etc.
        So many variables just to get the concrete to sit in a layer, harden enough to support next layer, and still be wett enough to bond with the new layer and hit the spcified strength…
        Love to see it work.

        1. As for the number 1 reason concrete doesn’t reach designed strength being that someone adds water to “soup it up” for the purpose of improving workability, therefore exceeding the water cement ratio of the mix design, that might have been the case with ready-mixed concrete of not long ago but not so much now with the water reducing admixtures used in the latest mix designs.

  4. While I don’t see an immediate need for this tech, it’s hard to deny the future possibilities. I hope they find success or at least learn and publish their findings if they fail so that it can be continued by others. A lot of people are talking about how it’s not faster than just throwing up some lumber walls etc, but being in COVID times, contractors are still quoting six months to a year lead up time to get their hands on building materials like lumber. My wife and I had an architect make us designs for our dream home (more or less, nothing fancy just the right size and layout that we want), the contractors we reached out to as of six months ago were telling us it would be a year to get materials, so they wanted us to pre-order the materials while working on getting all of the approvals etc, to save time. Needless to say the cost of materials and time has halted our plans. If this tech has the possibility of being an alternate solution to save time based on materials readily available at the time during the design phase, I can see it being a reasonable solution depending on your needs.

  5. I recall somewhere inland (Fresno?) is a lady that took posession and is living in her 3d house. Somewhere else a company is building tip up style factory/warehouses so it appears that some claims are inaccurate except for that jurisdiction

  6. If we’re going to print houses out of goop anyways, why not just abolish all building codes and let people build their own shelter like every other animal on earth? Or is this just a scheme to funnel more money into tech companies at the expense of the people who actually have to use their products, as per usual. People can’t afford houses and they’re building this nonsense just to tear it down. Let them eat hempcrete, I guess.

      1. Honestly, good. So many problems are caused by people living in houses that are constructed beyond their own level of comprehension. Working retail at a hardware store and having to sell people various goops and patches to keep the water and animals out of their house really makes you appreciate the humble mud hut.

          1. I’m saying people typically regress to mud-hut tier repairs until their house is unlivable, at which point they either hire someone smarter to essentially rebuild it, or sell it to someone who will. Easier to just have them live in an actual mud hut so they can fix it themselves. It’s all most people are capable of.

    1. Building codes exist for a reason. Some of those reasons are stupid e.g. minimum square footage requirements, but those are the exception. Like OSHA rules, the vast majority of building code requirements are written in blood.

        1. No, it’s not like that.

          Let people build the way they want, and instead of homeless you have massive fires… Brazil’s slums are built without any regard for construction code because people don’t have money nor knowledge to do better. When a fire breaks out several blocks burn to the ground.

          I agree that there’s too much bureaucracy involved that is there “just because,” but a great part of the building codes are justified.

          1. It is like that, actually. Most people can’t afford a house nowadays, and they also aren’t allowed to build one themselves (for their own “safety”). It’s state-mandated poverty.

          2. The problem with letting people build stuff on their own that is dangerous to themselves is- it isn’t just a danger to themselves. It is a danger to neighbors or if they hurt themselves or their janky hut falls down the rest of the infrastructure of society like police, fire department, EMS, medical and hospital get involved. On a large scale letting people suffer their own dumb consequences just does not work. Unless you are a truly die-hard grizzled poor person that refuses to use medical care, electricity, and all that.

        2. Like everything important, it’s a balance.

          Most early building codes are written in blood. Many later building codes are written in cash.

          Nobody cluefull can look at modern American construction and say building codes have improved things. You could make an argument that it would be even worse with no building codes, but that’s not the same as status quo.
          Mega scamfull nationwide corporate builders, tension slabs, intoxicated tradesmen, bribed inspectors, HOAs. It’s joy to own a 1950 house on a half-acre.

        3. How about going to a club and having the floor collapse under you or perhaps you neighbors house catches fire and takes your with it because wiring was faulty. Codes exist because of these things. The reasons most people are homeless have very little to do with housing availability and much more to do with mental health and education issues.


            It looks to me more like there’s housing available, but people aren’t able to afford it or find it.

            On average, there are 27 empty homes per homeless person in the US.

            The houses might not be where the homeless are, but there’s housing available.

            Maybe folks ought to look at moving to where there’s housing.

    2. This comment is just absolute nonsense.

      So what if the house is made out of “goop”, it is concrete like many other houses are made of. How do you think the other houses concrete is made? It starts off as “goop” too, it is just poured into molds in a factory or poured on site in molds.

      Do you realize why building codes exist? A lot of it is for safety, minimum distances for fire, fire suppression systems, electrical safety, water safety, etc. look at what happened before building codes existed, whole areas of cities burned down from single fires.

      Places like you seem to want where everyone just builds whatever they want exist, why don’t you move to one of those places? One of the reasons people live longer is due to houses and building codes. They have sufficient shelter and warmth, safe cooking equipment and water, amongst other things and you are less likely to die because of your neighbour left the oven on or did their own electrical work. Due to the building codes or regulations things are safer.

      Are you really that mad that they printed a house and then demolished it? It was just a prototype essentially. Would you rather they just built houses that weren’t safe? Companies build and test houses all the time, especially in areas where there are hurricane or earthquake or flooding risks. You just don’t hear about them because they aren’t exciting or new. If their prototype house isn’t good enough they tear it down (if it’s still standing) and they try again. It’s far better for everyone than just selling it and having people be injured or killed due to it.

      “So many problems are caused by people living in houses that are constricted beyond their own level of comprehension.”, so what? Not everyone is a builder. Should people stop using electricity because they don’t understand how power plants work? Should they stop using cars because they aren’t mechanics? Should they stop using electrical devices because they don’t understand how they work? Humanities biggest strength is building on the work of others and collaboration. You could apply your comment to practically any part of modern life. What is your problem with it though? That you worked in a retail store and people had to buy stuff? Really? Is that the best you could come up with?

      If you want to practice what you are preaching then get rid of all your belongings, clothes included, and go and live somewhere where you won’t interact with anything made by another person. Then you will be free to build your mud hut and only use things that are within your level of comprehension.

        1. So because I took time to write a reply that makes me an “overeducated nerd”? It hardly requires any education, it is common sense. At this point you must be a troll, either that or you are incredibly stupid.

          If you aren’t interested in reading replies (which you have done and responded to quite a few times already) then why bother writing comments?

          Where do you live that everyone just lets their houses degrade and fall to pieces? In case you didn’t realise, most of the world isn’t like that at all. It takes some serious mental gymnastics to go from people being unable to repair their houses and having to pay people who can do it to people should live in mud huts since houses are too advanced for them. Have you really based your whole opinion on the fact that people buy stuff from retail stores?

          You have a very much warped perception of reality. Can you really not handle anyone countering your opinions? Saying that you are not going to read it just makes you look worse and even more like a troll. My comment isn’t left solely for you anyway, it’s a public comments section.

  7. Haha.. But seriously what was the purpose of the hemp I wonder? They ended up using all the same carbon-intensive stuff, and it seems like it just made it structurally weaker.. Just for the buzzword I guess? Oh these houses ended up being worse for the environment instead of better like we promised, but check it out we put weed in it so that’s cool right

    1. Hemp != Weed

      They’re using hemp to increase the insulating properties of the material (for both sound and temperature) at the expense of some compressive abilities that you’d see in standard concrete constructions.

      Additionally, if Hempcrete can be successfully used it would be good for the environment as the structures using it would act as carbon sinks.

      They don’t have it perfectly worked out. If they don’t get it maybe a different company will. Or maybe we learn enough from this method to improve others.

    2. Sometimes its also because its because it leverages the existing interest and enthusiasm students have alredy demonstrated for the product which helps get them fully engaged in participating.

    3. I don’t actually know *their* intent however fibers (of any sort) are strong in tension and concrete is not. Concrete is GREAT in compression. This could theoretically give it some better strength than pure concrete though that didnt seem to pan out. that *could* have been amongst their intents for including hemp.

      Side story: while working on my mechanical engineering degree I fond a fiberglass/tooling shop that would employ me whenever I was available. Mostly what we made were not parts, but part models and tooling. In other words we made the parts on which you make the parts. So we added framing to the back of our parts to make them sturdy and rigid. The typical process for that was to apply a plaster to the back of the fiberglass tooling part, then use hemp fiber and plaster to tie all of that in to some steel pipes. the hemp fiber saturated with plaster made for some very strong and rigid connections from the tooling piece to the steel.

  8. Why I have a “solar roadways” vibe from this project? Especially with the use of 3D printing that is not suited for making stuff cheaply. Just do, what socialists did before: pour big, flat slabs of ordinary concrete in reusable forms, and then use them to construct the building. Slabs are easier to transport and assemble than premade rooms or houses, and can be manufactured quite cheaply at scale…

    1. If you take into account that this is a school project, the purpose of the project is to train their students. The house is a collateral effect.

      School projects don’t have to scale, don’t need to be cheap, don’t even have to make sense.

    2. I agree, but, this is associated with a educational program which makes me think it qualifies more as research or experimental technology/approach. Why shouldn’t they give it a try, see how it goes and publish the results? I doubt we will see 3d printed houses become common unless something major changes, but, we may as well let them experiment with it.

    3. In its current form it may not be suited to making houses cheaply but in a lot of cases 3D printing can be the cheapest and best way to produce parts.

      One major problem with just using prefab concrete is that every house ends up looking the same and the houses generally aren’t that great. Sure it is cheap and fast but that isn’t necessarily good.

  9. Nothing is perfect the first time around. Science is about hundred of fixes and changes before getting it right. As for knocking it down…that what you do…it not right so you start over. To be honest I would think recycled polyethene from plastic bottles would be a better material than hemp; but the point of this is that IOWA harvest hemp and they are trying to make ‘another use’ for it thus improving the economy of the state of Iowa? You would think builders would want to find a use for what the farmers make – but but I guess sneering at any attempt innovation from a local college is what knuckleheads want to do instead.

  10. The comments on here are hilarious. 3D printed houses have been an emerging tech and not just some crazy pipe dream. Down in Texas they are building entire subdivisions with concrete 3D printing, which is cheaper and faster than traditional home building techniques (The machine can run 24/7 with just 1 or 2 human operators supervising it) It was featured on 60 Minutes a few weeks ago. Don’t knock on the tech before you have a decent understanding of how it works. I would love to live in a concrete house.

    1. sure,
      if your only consideration is initial cost.
      Stick built homes have a much shorter lifespan and a much higher maintenance cost than a number other construction techniques.
      Myself, Id sooner live in a well stacked CSEB structure than any of these extruded concrete atrocities.

      1. If you let the roof go, it doesn’t matter, at all, what’s under it.

        I know where you can get a house in Germany for five euro. It’s teardown cost exceeds the value of the lot. House was built after WWII, west not former east, barely. Truth: It’s almost certainly gone by now. Village was going to eat the cost and sue estate.

        We all like ‘well stacked’. Yeah, stacked!

        Another advantage of stick built is easy retrofitability. Depending on the details. Nice tall crawlspace or basement, single story and everything is easy. You don’t really want to live in a 100 year old brick house.

        1. >If you let the roof go, it doesn’t matter, at all, what’s under it.
          Lifespan of a wood shingled roof 30-50 years
          Lifespan of a Plywood decked Asphalt shingled roof 15-30 years
          Lifespan of a metal roof 40-70 years
          Lifespan of a Tile roof 50-100 years

          I know where there are dozens, hundreds perhaps even thousands of 100+ year old buildings for sale that are still standing strong. The hills of italy and spain are dotted with such opportunities. Many are walkin livable, Many need insignificant renovation, and sure, many are little more than STURDY shells waiting to have their interiors rebuilt entirely due to decades of neglect. Some will cost you just a few euros to secure, if you can show the municipalities you possess the means to rehab. But most will cost you less than a years pay to secure in walk in habitable condition. A family member purchased a beautiful old turnkey house in sicily for $30k USD just before the pandemic hit. Of course youll need to bring your own employment opportunity as the entire reason these houses became abandoned is generation after generation moving to nearby cities, or emigrating to far away lands.

          I, however live stateside in a four story 240 year old brick building with a spanish tile roof. No complaints here. So “you don’t really want to live in a 100 year old brick house.” doesnt apply to me.

          While I am content in my old brick building, I acknowledge that a Stacked CSEB building has a longer life with less maintenance and lower carbon footprint than my current home of fired bricks and mortar.

          1. And Ireland (recently?) has a program to encourage people to move back out to 30 Islands, by offering €80k(?) to renovate neglected homes and live in them. Sicily has a similar program.

  11. Recycled plastic might make a good filler in concrete, you know, poly fibers from shredding. Concrete manufacturing is the worst CO2 emitting process so I bet we will see robot workmen sooner than this kind of thing.
    My friend from Brazil says they construct in brick and concrete and the wiring and plumbing is really difficult.

    1. A lot of tropical countries have to construct with concrete because of things like hurricanes, typhoons, and termites destroying wood in short order. In Japan almost everything coastal is concrete which is why typhoons dont blow down homes very often unlike geniuses here that build wood framed homes in Florida.

      1. One piece of common wisdom back when I lived near a barrier island on the gulf coast was that if you wanted beachfront property, build a house a few rows back and wait for a couple hurricanes to come in. I think it’s a bit less true once they got the seawall.
        But the other one was that the kind of house you want isn’t one that’s made all of concrete in order to not get blown down or something – instead, get one on stilts and keep everything important up high out of the floodwater, even if it’s still got a wooden frame. You can even wall up the underside as a garage, but make sure the walls will easily break away. If you can’t afford either one, either go with something cheap and don’t get too attached to it, or use something that can be moved.

  12. Here’s a great new technology, since we’re using taxpayers dollars (aka grants), let’s insert a experimental material into the middle of it!

    I don’t know why we’re 30 trillion in debit… No idea, none whatsoever.

  13. Yeah I’m betting they didn’t run a moisture test on the aggregate after they got the mix out of the lab.
    As much as I love 3d printing and construction I always thought this was just a silly application compared to the standard methods. Tilt up/ precast panels/walls would make much more sense and could be done multiple times per day.

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