Energy Service Agreement (ESA). An ESA is a financing option for building energy efficiency projects where the service provider pays for the upfront costs of any new equipment and performs both routine and emergency maintenance. ESA contracts include standard, predictable payments, while the building owner benefits immediately from having new modern HVAC and related equipment, a better tenant experience, and generally lower energy costs. The equipment acts as collateral, so an ESA doesn’t require a lien on the building itself. “Unleashing Energy Efficiency Retrofits Through Building Performance Contracts” www.osti.gov/servlets/purl/1236618 . “Energy Service Agreements (ESAs)” www.energy.gov . “Energy Service Agreements: Potential Big Kid in Town?” www.aceee.org .