Changes in operations can save 5-30% of building energy use at low cost, yet these changes are often not implemented. Little attention has been directed toward understanding why. This project focuses on how building operators approach energy use and conservation in their work, viewing the building as a social system. It draws on interviews, a workshop, surveys, and case studies, learning from operators, facilities staff, researchers, policymakers and occupants. We found two clusters of obstacles to lowered energy use. First, while building operators have the technical means to reduce energy use, social, organizational and technical constraints limit ability and motivation. These include low status, customer service practices, poor feedback on occupant environment, little energy data, and technology shortcomings. A second cluster of obstacles rests on the fact that current combinations of buildings, management, and expectations leave many occupants dissatisfied with indoor environment. Recommendations call for shifting the focus of energy use reduction strategies to better include building operators, who are in an ideal position to shape and vet solutions. These include (1) increasing status and visibility of building operators; (2) improving ability to see how energy is used; and (3) attending to indoor environment in coordination with energy efficiency.