My coop is almost done but i need to put in the roost pole. i was going to put it on my north.wall but i am concerned about putting it in front of the vent. The north wall is 4 feet high with a flap vent making up the top 8 inches. I was thinking of putting the roost about 12 inches below it which would give them roughly 20 inches of headroom. will they catch a chill in the winter? I live in northern ontario where we have long and cold winters. i was thinking i could insulate and close the vent for winter. the rest of the walls have large windows or the door. Should i put the roost lower? I was hoping to put a dropping board below the rost so i need at.least 18 inches of headroom.