First time chicken owner building a new coop. I plan on insulating the roof to prevent solar heat gain in the summer. The walls will be shaded by trees during the summer. I question the need to insulate the walls in view of the amount of venting that is required even in winter. I plan on starting out with 10 chickens in 80 sq ft in a 120 sq ft building. There won't be any drafts in the roost and nest box area. Located in SE Michigan where winter temps can hit -10 to -15 a few nights a year.