Our neighbors growing up had a house built into the side of a hill like that. It is warmer in the winter, and cooler in the summer. It really seemed to work wel

Our neighbors growing up had a house built into the side of a hill like that. It is warmer in the winter, and cooler in the summer. It really seemed to work well, if you don't mind part of the house not getting light. They put a ton of windows/skylights in the front to mitigate that.