Despite a recent increase in the greening of existing buildings, the literature continues to focus on investigating barriers to the greening of new buildings. The goal of this research was to develop a method using failure mode and effects analysis to investigate the barriers to the greening of existing buildings using the Leadership in Energy and Environmental Design version 4 for Building Operations and Maintenance: Existing Buildings rating system. Its specific objectives included using this method to 1) investigate potential failure modes when certifying existing buildings using this rating system, as well as their causes and effects, 2) rank failure modes, effects and causes in order of priority and 3) identify opportunities and lessons learned from implementing this method. The research involved bringing together a focus group of five local experts who were familiar with the rating system for a one-day workshop. The experts, along with the research team, were tasked with identifying these potential failure modes along with their causes, effects and detection controls and with rating the probability of occurrence of the failure modes, the severity of the failure effects and the ease of detection of the failure controls. The analysis of the workshop data showed that over half of the identified failure causes were technical in nature, with financial causes and organizational causes representing 14% and 11% of all failure causes, respectively. The analysis also showed the intricate relationship between technical, financial, organizational, social and environmental factors; therefore, these different factors need to be integrated and interlinked, rather than compartmentalized and separated. This research provided a new comprehensive method based on the use of failure mode and effects analysis to evaluate the risks to the greening of existing buildings using the Leadership in Energy and Environmental Design rating system. Workshop participants found failure mode and effects analysis to be an excellent method for identifying, evaluating and ranking green building certification risks because it helped to foster interdisciplinary collaboration between participants from various disciplines, as well as between researchers and industry stakeholders. Nevertheless, there is a need for future applications of the method to limit the scope of the analysis to specific categories or credits of the rating system. This narrow scope would facilitate the analysis of the workshop data and enable a more in-depth and comprehensive analysis of all risks and risk types, including ones that traditionally tend to be ignored, such as organizational and social risks. (C) 2016 Elsevier Ltd. All rights reserved.