Deesoundm,
As answered to your DM :
As far as I know, last time I checked with local urbanism administrations, these were not allowed in the coastal areas (only classic reinforced concrete constructions are allowed - due to high anti-seismic norms).
So you could probably build one as a "temporary structure" but I doubt you would be able to record in the land registry and gain residency with this.Â
For the mountain areas where wooden constructions are allowed, that's probably ok.
Someone can maybe confirm (or not) what I say.