High-performance sustainable facades can be defined as exterior enclosures that use the least possible amount of energy to maintain a comfortable interior environment, which promotes the health and productivity of the building’s occupants (Aksamija, 2013). This means that high-performing facades are not simply barriers between interior and exterior; they are building systems that create comfortable spaces by actively responding to the building’s external environment, and significantly reduce buildings’ energy consumption. Building performance simulations are an integral part of the design process for high-performance facades, since they help in investigating design options and assess the environmental and energy impacts of design decisions. In order to evaluate and optimize the building performance, different analysis cycles should be part of an integrated design process. This article discusses methods for designing high-performance facades, integration of simulations and modeling with the design process, as well as two case studies.