The Holy Cross School is located on the grounds of the historic Mission San Buenaventura. The site presented significant archaeological, geological, and geotechnical constraints. It is within a State of California Fault Hazard Zone, and the buildings of the existing school are adjacent to a moderately-high slope over non-uniform soils.

Earth Systems conducted a fault exploration program and provided recommendations for slope stabilization. Much of the design included a pier foundation system for the reconstruction of the existing elementary school and the construction of a multi-purpose auditorium.