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I like the idea. Have these been put through stress tests? i.e. Wind tunnels, simulated forest fire, floods, earthquake, cold / hot weather, powder actuated projectiles and how do they compare to traditional wooden framed or steel framed homes? What is the thermal insulation rating? I would expect thermals to be pretty good. I've seen similar designs using aircrete [1] and those are fire-resistant. How strong is this compared to aircrete?

[1] - https://www.youtube.com/watch?v=4VcdwDRNPzA

⬐ adriancr

I assume it has the same longevity as things built out of mudbricks...

⬐ sneak

So, it's going to have to switch to a subscription model eventually to continue to exist?

⬐ bogwog

gotem

⬐ abdullahkhalids

In my country, some poor people (unfortunately) live in mud houses. They periodically add a new layer of mud, as the old layers get eroded away.

I imagine, this could be done by a robot for this 3D structure.

Of course, this depends on house not collapsing under heavy rain.

⬐ sneak

Creative Ground.

⬐ adriancr

or critters digging through walls and into your house

⬐ lhpz

The thermal resistance of raw earth is not good, similar to that of concrete. Thermal conductivity is around 10 W/m.K. To be compared to 0.1 W/m.K for a typical building insulating material.

But raw earth is porous and will store moisture, hence behaves like a two-phase material. Water in the earth may vaporize or condensate in the pores, which helps in regulating indoor moisture levels, and explains the high thermal storage capacity of the material. Since earth is cheap, it's also possible to build thick walls and get a high thermal storage capacity in the building envelope. Sun heat will be re-radiated a few hours later at night during winter, and some the cool of the evening nights will be available indoor during summer days. Because of this high thermal capacity, raw earth buildings are good at this so-called thermal phase shift. But raw earth is still a poor insulating material.

⬐ LinuxBender

Thankyou for that really detailed explanation. That reaffirms for me that I will most likely stick with aircrete and concrete/shotcrete when it comes time to build a few hobby structures I had in mind.

Out of curiosity, could you suggest what material would be best for storing heat from the sun? I am going to build a greenhouse that will face the south and have a wall on the north side to absorb heat. I have seen some people use clay with a black metal wall and some use black barrels of water. I want to be able to extract some heat from it using pipes. Any thoughts on what might be even better?

⬐ lhpz

If you want to store solar heat, you cannot beat water @4000J/kg.K. Black barrels of water is probably the best solution, yet a very simple solution. I've checked the thermal capacity tables, only ammonia would do a slightly better job than water !

I also toy with the idea of building a greenhouse myself, that's why I have done some research. If you want to harness the thermal capacity of earth for a greenhouse, I know of two tricks:

- Excavate one or two meters of soil to build a “pit” greenhouse. You will get earth walls connected to an immense thermal storage capacity. This is the so called Walipini greenhouse concept https://en.wikipedia.org/wiki/Walipini

- The diurnal and seasonal temperature oscillations dampen quickly with depth in the ground. Below some meters of soil, the temperature will be stable at the average annual temperature at your location (Ta). If you can dig a trench to lay underground pipes to create a ground/air heat exchange connected to your greenhouse, you will get a free source of air heated at (Ta) in winter or cooled down to the same (Ta) in summer. Fans to force air circulation will help.

⬐ LinuxBender

I too have been looking into a sunken greenhouse and using geothermal venting and long pipes to bring the port temperature closer to earth, somewhere near 50 degrees F. Much easier to heat or cool that than the outside air.

Thanks for the tips on the water. That has the benefit of having emergency access to water if I need it. Also much easier to build than a clay wall.

⬐ LinuxBender

Interesting. I had not seen aircrete before. It apparently has about 50% of the strength of concrete and has been used since the 1920's. [1] Being very light is a great property. I can think of many uses for this.

[1] - https://en.wikipedia.org/wiki/Foam_concrete

⬐ peter_d_sherman

There's a lot of great videos on YouTube about it; how to make it, how to use it, capabilities of it, etc., etc.

Apparently it can be made cheaply, with relatively modest tools...

If graphene is the new wonder material for electronics and electronic devices -- then certainly aircrete is the "new" wonder material for housing construction...

Also great is that it saves builders from using as much wood; which in turn saves forests/prevents tree depopulation, etc.

⬐ LinuxBender

I am already envisioning projects I could use that with. I will find those videos. I am curious to see if anyone has used it with a shotcrete sprayer. I bet they have.

⬐ peter_d_sherman

Also, if you are entrepreneurially inclined, if you learn how to make Aircrete well enough (post learning curve that is! <g>), I'll bet you could sell your self-manufactured Aircrete bricks -- to various parties...

In other words, Aircrete might make a good product for a future business, if you were so inclined...

(The reason I point that out is because it's on my list of "things that might make good products for future bootstrap businesses" (although, there's probably one too many products on that list already! <g>))

⬐ peter_d_sherman

Note the synergy here between Dome Homes and Aircrete...

Also interesting is the use of counterweights during the construction process to prevent the increasingly angled dome walls from collapsing during the construction process...

⬐ yhoneycomb

this guy is insufferable

⬐ filoeleven

I’ve wanted a dome home since I first stumbled upon one in high school; my friend’s uncle lives in one. His is a wooden geodesic, which you can get kits to build starting at $30k or so for a smallish one. They can be erected in a week by two people with power tools. They can also be multi-story.

$11k is a significant amount of savings, though I’m wondering about the logistics of running plumbing and electricity. (That might be covered in the video, I’ve seen it before so didn’t watch through again.)

I’m in no position to undertake such a project anytime soon—missing the land, time, and funds—but it’s always cool to see it pop up.

If you like alternative house styles, and especially this kind of some, you should check out earthships too. Even higher efficiencies/lower carbon footprints, but friends who stayed in one say they haven’t really worked out the bugs yet.

In any case, stick frame square housing is a “good enough” idea that we have been treating as “solved” when we really shouldn’t. In a lot of places, even building a wood-frame dome home requires all kinds of extra paperwork and time investment with codes enforcement because it’s unfamiliar to them. Not sure how to change that situation.