I've got an old shed that was used as a granary. It's unisnulated, about 30'x20' with wooden walls, has great sun exposure, has water and electricity, and is fairly close to the house. Since we moved into our property 2 years ago, I've been eyeing it with the thought that it would make a great greenhouse. We live in southern Minnesota with harsh winters.
I live in Minnesota and am wondering what materials would be best for the southern wall and south facing roof if we are to transition it to a greenhouse-type building. How much insulation should we put on the north-facing walls?