While browsing pinterest, I found this image with a reference on it to a book. It looks like a more managable project for a lone homesteader than a full wofati, although I'd be tempted to dig the walkway a foot deeper and put a floor in to create more of a coldsink.
This book comes at the peak point of the country garden but just before the mass commercialisation of food production. It has a lot really useful information about solar building design, obviously some of it no longer applies i.e. lead based paints.
You can find the book as a pdf here.
Horticultural Buildings