So a few weeks ago I studied under Sepp Holzer, the super permaculture guy.
As part of it, he talked about his philosophies on root cellars and animal shelters. He has a basic recipe for both. He even talked about how you can build one and later easily convert it to the other.
I have a lot more pictures of [url=https://www.richsoil.com/sepp-holzer/sepp-holzer-permaculture.jsp]Sepp Holzer's root cellar[/url].