Many utility companies will do an energy audit for free, and they'll send you a list of both major and minor repairs, breaking down how much you can save on your energy bill by doing each one.
For example, most homeowners can save between 5 and 30 percent on their energy bills just by sealing air leaks, a fix that you can often do yourself with a caulk gun [source: Energy Savers]. If your utility company doesn't offer an auditing service, you can find professional auditors or even perform one yourself. The U.S. Department of Energy has a very useful checklist for performing your own energy audit.
No matter who does the audit, if you have a professional coming in, make sure that he or she uses a blower door test, which uses a high-powered fan to detect air leaks [source: Energy Savers]. The auditor will either provide you with a list of repairs you can do on the spot or send you one a few days later.
Ready to seal up those air leaks? Before buying a ladder to caulk any hard-to-reach places in your home, read up on saving through swapping on the next page.