The whole top is open how is that not enough ventilation. Its 8 feet of ventilation. Does each chicken need a hole to stick its head out of? If it had anymore ventilation it would be a open box is that what yours is. Hows it wasyed space underneath when its part of the yard.
Its really nice my wife loves it its simple to clean and maintain. I put linoleum flooring so everything wipes clean. I also made a sand box the length of the coop it catches most of the roosting poop. It really is a nice coop and no rain inside so far great design.
I just set a red trough feeder inside i used to put a gallon waterer in there but it seemed like they stayed in there allday so if they wanna drink they have to come out. I also added a 2x2 above the walkout door the length of the coop for a roost bar i have my sand box under that. Some of them still prefer to roost on the upper 2x2s and my marans prefer to sleep in the walkout door entrance for some reason. Im on vacation till Sunday I'll add some pics then.