The U.S. Federal Housing Administration recommends a minimum of at least one square foot of attic ventilation (split evenly between intake and exhaust) for every 300 square feet of attic floor space. This 1/300 rule is general and may not apply to all buildings. It’s typically the minimum recommended standard that should be used for ventilating attics. But make sure you do not over-ventilate, since too much ventilation can be a problem as well. An excess number of roof penetrations can cause leaks and other problems during extreme weather.
If you are not sure if your attic is properly vented, or if you’ve had high cooling and heating bills in the past, now is the time to call a reputable roofing contractor in your area, who will check your attic and roof to determine that you have the proper amount of ventilation your attic requires.
And since windows, doors, and appliances can also waste energy if not addressed or maintained properly, take a further look around the rest of your home to address energy efficiency and keep your home as comfortable as possible. The Department of Energy has some useful tips to help you audit the energy-efficiency of your home and save money.