Conducting a home energy audit can help you determine what aspects of your home are consuming the most energy and where changes can be made to help you save money and increase your energy efficiency. You can conduct a basic energy audit yourself or you can hire a certified energy auditor to come in. Although having a professional auditor assess your home will be more comprehensive, even doing it yourself can help you determine what areas of your house can use the most improvement.
Below are some useful resources to learn more about doing a home energy audit yourself or hiring a professional:
California Building Performance Contractors Association
Or contact your local power company.