Generally, if you follow through with the upgrades recommended by your energy auditor, you'd be able to save between 20 percent and 40 percent on you energy bills. Assuming you spend the national average on energy, which is $2,300 per year, and you improve your home's energy use by 30 percent, you'd be able to save $690 per year.

The great thing about the $690 in savings is that energy auditors in the Philadelphia area charge around $500, so you'd still be able to save $190 extra dollars that you could use toward the upgrades in the first year, not to mention the money you would continue to save for years to come. The money saved on utilities, which can be used to pay back the money spent on upgrades, is often referred to as a "return on investment."

Auditors can give you a general idea of the return on investment for upgrades, like insulation, air sealing, duct sealing, appliance upgrades, etc. This will help you to decide which measures will be most cost-effective and which measures you may want to wait on until you have a bigger efficiency budget.

To get an idea of where your home stands in terms of energy efficiency, you can use our quick and easy online energy audit tool.