The rustic original feature: the tiny stairs up to the next room (often featured in old homes that were partly dug out of a big rock).
Cob homes! And the website has more construction types for sustainable housing I'm loving these example of larger family sized cob homes that don't all look like hobbit holes. ;) I like that cob can be freeformed, but I would like it to look a little more like a 'normal-to-us' home as well. (and fit our family of seven)