https://www.dailymail.co.uk/sciencetech/article-10268041/Worlds-eco-sustainable-houses-3D-printed-Italy.html

The homes of the future? World's first eco-sustainable houses
have been 3D printed in Italy entirely from local raw EARTH

.. . .

Who are they kidding ?

Mud "bee-hives" - and they could have been built
a lot faster and cheaper using conventional molds
rather than 3-D mud printers.

Toss in about 10% concrete powder and resin too
if you want them to survive a few rainstorms ...

Adobe construction does have it's place - and that
place is in EXTREMELY dry climates. Even then it's
the practice to coat the bricks with an asphalt-
based compound to shed water. Still, a couple of
wet weeks and all you have left is a pile of mud.

Durable eco-construction is a difficult business.
Wood/fiber absorbs water and rots - and I'm not
aware of any suitable polymeric wax that will
permeate every fiber for protection. Concrete
IS eco-unfriendly, takes a HUGE amount of energy
to create. Depending on the area - like areas
that don't have earthquakes - local flattish
stones with a concrete-based mortar may be the
best bet ... 90% less concrete. For earthquake
zones though ... well ... the Inca figured that
out with specially shaped interlocking stones
that quakes would simply help settle even
tighter together. Those were labor-intensive
however.

I've seen houses built of recycled plastic in
India and Africa. But there isn't enough of
that for the larger market.

It's a PROBLEM. How to build houses that are
both strong, affordable and durable without
requiring insane amounts of energy or rare
materials.

There was a sci-fi short long ago - Bradbury
I think - which envisioned future humans living
in something like tents (presumably of advanced
materials). Yurts sort of fit that bill, but the
modern popular ones use lots of wood framing
and aren't really yurts - just round houses.

Oh, if you want yurts, GoogleEarth Ulanbaatar
Monglolia ... seems like everybody has one, even
if it's in the backyard of their conventional
house. Hundreds of thousands of yurts stretching
to the north .....