There is an increased desire for higher level of building performance during and after seismic events in the mission critical and data center industries due to the costs associated with non-structural damage and uptime losses. Conventional industry-accepted approaches such as voluntary use of an importance factor may increase the robustness of the structure itself, but don’t result in reduced floor accelerations and impacts on both computer servers and the extensive mechanical and electrical distribution systems associated with data centers. Seismic isolation remains the premier solution for increasing both structural and non-structural performance during a seismic event. The authors describe the project challenges in the design of two base isolated facilities located in California. The first project is located in Northern California and was for a client operating their data center in a “collocation” format. This project was located on a site with tight space constraints, necessitating the use of fluid viscous dampers as part of the isolation system to limit building displacement to an acceptable level. The second project is located in Southern California and was for a single “enterprise” client. For this project the site was larger, allowing the team to design for a larger displacement to maximize the effectiveness of the isolation system and minimize the demands imparted on the building.