What you can assume with a manufactured coop is that they know nothing about proper poultry housing. They are carpenters, not poultry experts.It's a prefab chicken coop. I'd assume the manufacturer took ventilation into account? I specifically bought a prefab kit so I wouldn't have to worry about things like measuring vents and windows.
The capacity they claim their buildings will hold is commensurate with that in egg farm cages. Not what chickens really need.
Why else would they put 4 nest boxes in a coop that can barely hold 4 chickens. They are overpriced, undersized buildings with no where near enough ventilation.
If you haven't measured 1 sq. ft. of opening (around the clock) per bird, it is usually insufficient.