, valleys and hips then the homeowner has some options. If it happens that the home has an open attic space, the owner may need to add an extra square vent for each mixed portion of the roof. The person has the choice of using vents for each peak in a gable-style roof instead of using square vents. In a tall peak style roof, the taller the peak, the taller the vents have to be. The homeowner needs to install two tall vents in the attic space, they have to make sure that they are not across from one another which ensures that the air is being drawn in from the soffits instead of the vents exchanging air with one another.