I am unfamiliar with Villa Vals, but have lived in apartments that were partly underground and homes with subgrade basements.

The thermal characteristics of the surrounding earth will help you determine the extent that it is acting as a heat sink to help heat or cool the home, compared to acting as an insulator from the thermal aspects of the outdoor air. Big considerations in subterranean housing are ground settling and movement, and preventing infiltrations of moisture and radon.

Best wishes with your studies, Matthieu!

Thank you Brian Lee for you answer!

Actually I look at for create an easy technological system witch arduino and 2 thermostats to measure successively temperature at different deep in the ground, and in different kind of ground. Also I want to push it as far as possible studying humidity in these different kind of ground, because as you said that seems the great problem.

I just have another question: did you like living in such half-buried housings?

It was mixed.

Positives: less outside noise, insulation from extreme heat and cold, cooler in summer,

safer in windstorm, tornado, and thunderstorm

less sway during earthquake, bottom level apartments cost less.

Negatives: cooler than upper level in winter, water leaks especially through cracks due to ground movement, concern about upper floors collapsing during earthquake,

backup from clogged sewage pipes, humidity higher increases summer mildew,

snow presses against window or fills up window well,

easily burglarized so can't leave windows open when absent,

more bugs.

I now live in a one-level house which has no underground part.

It's been a long time since I played with single board computing. How do you like Arduino?

Yes I understand and I see the multiple problems linked to half-underground houses. I just have to make it counterbalanced by positives aspects of the infinite ground around.

I like arduino and I made many different projects with it already (you can see it on Youtube) like an automatic cake cut. I think it's a great tool to make scientific measure systems.