In areas where it is available, natural gas is the most common way to heat your home. Typically older existing natural gas furnaces are typically 80% efficient or less. New natural gas furnaces have a minimum efficiency of 80%, and are commonly available with efficiencies well above 95%, which can save a significant amount of energy. In our area the cost per 100,000 btu's at 90% AFUE is $0.94. New heat pump systems offer costs / 100,000 btu of $0.92 with an efficiency of 10.0 HSPF, so heat pump systems are now a great choice too. Click here to learn more about your fuel choices and heating efficiencies. Mini split heat pumps, and geothermal heat pumps offer costs which are lower still so they are worth a look for sure.