The design was modeled and evaluated during programming and design phases. The design team and client established an energy target early on in the design phase by benchmarking against existing peer buildings and identifying state of the art technologies. Thermal analyses for individual space types were performed to optimize the façade and the program was organized to maintain highly comfortable spaces for users. This user-centered design process resulted in establishing a mixed-mode approach and the selection of a low-energy radiant system for the extreme seasons. Performance modeling via thermal simulation, daylight simulation, and CFD were an integral, interactive part of the entire design process, especially for passive features.