to be fair, i'm not seeing basements and that landscape looks desert, so it's probably west coast which is prone to seismic activity. even if it's not a disastrous earthquake, out west they need the buildings to flex. wood is the structurally correct choice. your only other option is driving pylons into the ground and making the framework of steel which is way too expensive and frankly overkill. plus building any kind of serious addition is basically out of the question with that option.
United States