Sustainability has become a major concern for the construction industry. There has been a growing emphasis on green buildings in the last decade. Renovation is critical in terms of improving the energy efficiency of the building stock. In this paper, the green building certification process of existing buildings in developing countries is investigated. A qualitative case study methodology has been employed to gain a better understanding of the critical success factors of the greening and certification process. In this respect, six leadership in energy and environmental design (LEED)-certified projects in Turkey are examined. A framework is used to analyze the components of this process, including the drivers, resources, green implementations, barriers, enablers, benefits, and impacts. Unavailability of approved materials, poor design of the buildings, and difficulties with the documentation process have been major barriers. The barriers have been overcome through the commitment of the owners, top management support, and collaborative working among project parties. The findings of this study are expected to guide construction professionals in certifying existing buildings in an effective manner. Similar studies may be conducted for existing buildings in different countries, where different regulations and conditions exist. The proposed framework can also be employed to investigate the certification process of new construction projects. (C) 2015 American Society of Civil Engineers.