[header] How to be green at home [title] Insulate your home. [step] Nearly half of your home's energy expenditures come from heating and cooling. To reduce the amount of heating and cooling needed, it is important for your home to be well-insulated. 
Ideally your home would be well-insulated when it was built, but this is not always the case. To improve your home's insulation, hang thermal curtains over your windows.