Traditional house builders should have no problem building an underground house. It's not much different than building a basement, whoever built their house just did a shoddy job. If those builders made a traditional house with a basement with these same issues, you wouldn't come to the conclusion that traditional houses are bad or difficult to do.
Some friends bought a new house, to be built as part of a new housing site.
They got told by others who had already gotten their their homes built to avoid a certain contractor at all cost.
So they went with a large and reputable contractor, and things seemed to move along well. Then the guy decided to visit the site one day, and when he gets there he sees some slightly confused teenager at the bottom of a pit that was to become the basement. He asked what the teenager was doing there. "I'm here to pour the foundation", was the reply. It was obvious the kid was not in his element and did not really know what he was doing.
My friend was confused. First he confirmed the kid was working at the right place. The kid was. Then he asked how old he was and who he was working for. Well he was 17 and was the son of the contractor they were told to avoid at all cost...
Turned out the large reputable contractor didn't had sub-contracted out the work to the one firm they were trying to avoid.
I was going to say roughly the same thing.. Building bad foundations happens all the time and it seems less critical in a traditional house, but..
I know many houses that had incompetent foundation builders. The repair costs/complexity can be similar to the underground house even though the priority seems low in a traditional house. One of the houses was torn down due to the neglecting the problem. (It was a rental and no one cared about using the basement for the decade before it was inspected and condemned.)
In the underground case you really only have to get one thing right and it is just as stupid to get it wrong in the traditional case, but people are distracted and don't see it's priority.
I should have picked a better word than "traditional", which isn't quite right as you say. Perhaps "unproven", "run-of-the-mill", or "inexperienced". It may entirely within the skills of a good "traditional" contractor to do right, but there is at least a bigger downside with potential mistakes due cost of repair, if not a substantially greater chance of mistakes due to the abnormality of the building. So, it's important to be picky.
