I read his book and it is beautiful. I was fascinated by yurts and contemplated building one for a couple of years, still haven't eliminated the idea altogether but I've been looking more at wofati, ferrocement and roundwood. His approach to life and advice around simplicity is very good, the book is worth the money: it's not just about yurts.
I very briefly lived in the old yurt community in Bowdoinham, back when Carlo Pastore was watching over the place. I don't know much about how to build them (or if Bill Coperthwaite was involved directly in their construction, but they are his designs), or what they'd be like in the winter, but it was a sweet little place. Ours was starting to get a bit funky, leaky when it rained, etc, but the big yurt someone else was living in was well-kept, and had a nice woodstove. That was 8 or so years ago, haven't been back to see them lately.
Michael: Sorry for the late reply, must have missed the email notification. I wish I could do the wofati thing here but am pretty sure the Presumpscot Formation (marine blue clay) would shear it apart. No lack of clay for any future cob projects though. My book budget shifted but his book is still up there, hopefully I can pick it up relatively soon.
Jessica: Nice! Didn't know there was a yurt community there, I'll have to look into that. I have an Aunt who has lived in Bowdoinham for decades, will have to ask her about it. I'm up in your neck of the woods now and then, I do some occasional work for a couple who has a place on Dunn Road / Long Pond in Belgrade. If you could use another back for a project let me know and I'll see if I can make my way there.