In the past two decades, thermal airflow and air quality performance simulations have played an increasingly important role in the design of high-performance green buildings and, most recently, in green campuses and communities. In the best of circumstances, these simulations tools have fostered innovation by enabling consideration of unprecedented capabilities. This seminar reviews the scope, development, applications, and limitations of these simulation tools; considers case studies of larger projects that have relied on these tools; introduces students to the underlying theory of these tools through the guided development of their own simulations tools; and engages students in the application of these tools to their own design projects.