The feature of your coop has to do with the environment it is in.  If the winter does not go below freezing, your coop does not need to be very tight.   My geographic location requires that my coops to be fairly tight.  Ventilation is very important to get the heat in summer and moiture in the winter out, and the ammonia year round.
Here is my approach: every openings in every direction and can be closed.  This include windows, doors and vents.  Using cross ventilation and the fact that heat rises, I have two doors, two windows, soffit vents and gable vents.  Everything stays open (secured from predators) in summer.  In winter, I would open the down-wind openings.