Excessive energy costs
A possible cause of higher cooling costs could be insufficient attic ventilation, requiring the cooling system to run excessively.
In warm weather, inadequate ventilation will trap hot air in the attic, causing air-conditioning systems to work harder, or leaving your home's interior hotter and less comfortable.
In both hot and cold weather, moisture in the attic can become trapped and condense on the rafters if it’s not insulated properly. This moisture can drip down onto the insulation and reduce its effectiveness, potentially increasing energy costs.