ok, live in MO, so we have cold snowy winters, and hot humid summers. building our coop now. We were thinking of having our roof corigated tin, so there will be minni vents from the up curves in the roof. how many added vents that can open/close do we need? The coop 8ft by 4ft, and 4ft tall. The chickens will be free run most of the time (but we will have a chicken run for them when we are not home. also, how many windows do we need? Any tips on how to do windows CHEAP??