The seismic upgrade and rehabilitation of the circa-1875 Pioneer Courthouse in downtown Portland posed a list of challenges for the project team in the areas of site access, public safety and public transportation flow. But another facet of the project—how to prepare the building to withstand an 8.5 magnitude subduction earthquake—proved to be equally challenging. The solution lay in the installation of the first friction pendulum base isolation system to be used in Oregon. It works by literally separating the building from the earth, allowing the structure to move freely up to 18 inches in each direction. The system was installed under the building to preserve the structure's historic fabric.