This report, published by the Rocky Mountain Institute, Urban Land Institute, and BOMA International in 2020, explores strategies for pursuing low-cost, high-impact energy efficiency and green leasing in Class B/C office buildings. The authors suggest that many such buildings have untapped potential for energy savings and improved tenant satisfaction, and outline best practices for identifying and implementing energy efficiency measures, as well as for marketing and leasing green buildings. The report is based on interviews with industry experts and case studies of successful energy efficiency projects in Class B/C office buildings.