This procedure gives your attic the air it needs to properly vent.  In cold climates this equates to adequate moisture removal and the elimination of the associated problems, like mold growth and wood rot.  In hot climates, the super heated attic air can flow out the upper vent (if you have them), and draw cooler air in around the house.  This is what your architect and builder expected.  However, in most homes the insulation contractor may have plugged up some or all of your soffit vents.  Our home energy auditors have found most homes have this problem.  Check yours or click here to schedule an energy audit for your home (if you live in the Phoenix area).  If you have questions about your existing attic vents, take a few digital pictures and send them to us for evaluation.  Take advantage of our knowledge and free advice!  Please, no more than six pictures.  Take one of each side of the home noting to make photos of the soffits vents (if any), gable vents (if any), and one or two shots of the attic.