It is well known that significant performance gaps exist between the projected and actual performance of a building. But we can use post-occupancy evaluations to measure performance in terms of resource use and occupant comfort, health and wellbeing and work to close these gaps. This course introduces students to common building performance issues, existing performance frameworks and rating systems designed to characterize these issues as well as the various types of performance gaps. Next, the relationship between occupants, the building envelope and mechanical systems is explored, including the influence of each of these elements on indoor environmental quality and resource use.