According to the U.S. Department of Energy, about 45 percent of a typical homeowner’s utility bill comprises heating and cooling costs. You can save up to 50 percent on your energy bills, and re-insulating is a great way to increase the energy efficiency of your home. Specifics about how much energy you can save withinsulation depends on factors like the size and construction of your house, the type of HVAC systems you have and more.