I'm new to this forum. I'm amazed at all the good information and camaraderie! I just finished building my coop inside a barn here in freezing Montana. It measures about 8' x 10', has a concrete floor, and is insulated. I used T-111 for the inside walls. The nests are along the interior wall so we can collect the eggs from inside the barn without disturbing the girls. So far it's working well. Temp inside stays about 40 degrees, even when it drops to mid teens outside during the night. As soon as it warms and the snow melts, I will build an outside run. I'd like to make the run movable so I can drag it to different parts of the yard using the tractor. Any suggestions? Any tips I should know before I build it? Thanks everyone.