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Comment by abdullahkhalids | Hacker News Reader

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?

Edit: Waterproof? Earthquake proof?

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The closest traditional construction low-cost design I can think of, which is somewhat common in Mexico, is built from concrete blocks like this:

https://s3-us-west-1.amazonaws.com/contentlab.studiod/getty/...

This is actually higher cost than your typical American house, which is just built with panels of wood put together haha

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.

If this is the low-cost design, what would be high cost? Steel and glass?

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 don’t feel that this machine is ultimately meant for poorer regions with cheap labor. This is just mainly R&D.

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.

Another similar material is earthbags: http://goodearthglobal.org/faq

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.

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