An Energy Performance Certificate (EPC) is a document that provides information about the energy efficiency of a building. It rates the property on a scale from A (very efficient) to G (inefficient) based on its energy use, carbon dioxide emissions, and potential improvements. The EPC includes recommendations for enhancing energy efficiency, such as insulation upgrades or more efficient heating systems. It's often required when a property is sold or rented, helping buyers and tenants understand the energy costs associated with a property.