jgnat, did you not see my post above, to Black Sheep???
"Well, Black Sheep, these yurts originated in Mongolia, which is located just below Russia...
In fact, Mongolia has a climate similar to ours here in Colorado - except it's shifted towards the cold end of our spectrum. We get highs in the 90's to 100's+; Mongolia's high temperatures usually reach the 80's. Our low temperatures here can reach -15 degrees Farenheit, and Mongolia can get even colder...
True Mongolian yurts - or more properly, gers - are made with multiple layers of felted sheeps' wool for the walls and roof. That keeps things very toasty indeed, during a Mongolian winter...
Of course, people in other areas would want to use something other than felted sheeps' wool, I suppose - though the lanolin in the sheeps' wool keeps the rain/snow out...."