[1] https://youtu.be/A06vfELMIK8

I would call that a feature. Building forms is basically building the entire building out of wood (or metal), then building it again out of concrete. Single family homes or multi-unit low rises don't require low void high compressive strength. They need speed. Residential prefab never caught on in North America. Maybe this will. If it is cheap.

In adobe construction, too-high clay content can be as big a problem as too low. All clays are somewhat expansive, and the most plastic clays like bentonite are also the most expansive. If your adobe is too expansive it cracks when it dries and contracts. Including enough sand makes it less expansive and less plastic when it gets moist, and including enough straw† allows it to resist cracking.

When you need to build in adobe, you analyze the local soil first. If there's topsoil, you dig through it to get to the clay, sand, and silt that you need. If there's too much clay or silt, you can defecate some sand in a settling tank and pour the mud off the top. If there's not enough clay, you do the same thing but it's the mud you use instead of the sand at the bottom. If your clays are too expansive, or you have way too much silt, you may need to dig somewhere else, or grout your adobe with lime or ashes like they're doing, which shades into building with cement, as you say.

We have thousands of years of craft lore about how to get this to work, plus modern science. It's true that, like rammed earth, adobe works best in dry climates, but its range extends into wetter climates than you might think, especially in the wattle-and-daub form where you supplement the straw with wood.

The big problem with adobe nowadays is not that it doesn't hold up or that you can't make the soils work; it's that it's a hell of a lot of work because your walls are two meters thick, and they're nearly as dense as concrete, and it's slow, because you need to cure the bricks for months before you start construction. A double-wide trailer is just a lot more house for the money.

The potential advantage to 3-D printing your adobe or concrete instead of tamping it into forms, plastering it on layer by layer, or stacking it up in bricks is that you can deploy the material where you think it'll be the most advantageous. The ruffled outside surface will channel rainfall into the grooves where more of it can flow down the wall before it soaks in. Those big spaces you see inside the walls might help with insulation, they will slow leaching of water that can produce moisture or efflorescence indoors, they might let you cure the adobe in place in the wall instead of in a pile of bricks beforehand, and they remove most of the weight of the wall without reducing its buckling resistance. The dome-vault shape allows you to reduce your roof expenses greatly. And maybe squeezing toothpaste out of a CNC crane will be less work than a team of sweaty guys tossing 20-kg bricks up ladders all day.

Still, though, those gorgeous soaring vaults make me very nervous. An adobe wall collapsing on top of your kids would not be very fucking funny at all.

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† I guess straw is a "high-performance fibre-reinforced stabilizing agent". The amount used is typically around 1%, so maybe straw is higher-performance than Mapesoil, or maybe they're just arching the walls more than you would normally dare to do with adobe.