The American Institute of Architects (AIA) Committee on the Environment (COTE) is the oldest U.S. program dedicated to sustainable design. In 1997, COTE introduced its annual Top Ten Awards, “the profession's best known recognition program for sustainable design excellence” (AIA), to celebrate exemplary projects and give the industry guidance on how to integrate green building principles. In 2015, to mark its 25th anniversary, COTE embarked on a landmark research initiative to study the first two decades of Top Ten, published in 2016 as Lessons from the Leading Edge. Part of the research was to revisit the program’s criteria of evaluation, known as the COTE Measures of Sustainable Design. The result of this effort was to overhaul the program with a completely new set of principles and metrics. The 2017 Top Ten Awards are the first year to use new criteria such as economic impact and more robust metrics for health and resilience. In this presentation, three members of the COTE Advisory Group will present the new criteria and engage the audience in a lively discussion about what defines sustainable design.