A home energy assessment (sometimes referred to as an energy audit) will show what parts of your house use the most energy and suggest the best ways to cut energy costs. You can conduct a simple home energy assessment by doing it yourself (DIY) or, for a more detailed assessment, contact your local utility or an energy auditor. Also, you can learn more about home energy audits and find free tools and calculators on energysavers.gov, the Residential Services Network at resnet.us, or the Building Performance Institute at bpi.org.