What are the key steps in the energy modeling process to increase accuracy and properly account for the performance of the façade system? The limitations of past practices will provide a reference as the importance of early-stage parametric modeling is explored as a strategy to rapidly identify key factors driving the performance of different designs. New metrics that help focus design on the elements that drive environmental conditioning—such as TEDI—will be discussed as a more appropriate metric for energy performance than the more familiar EUI. The checks and balances required to ensure accuracy of results will be emphasized.