The site was attractive to the Bourns because the views of Crystal Springs Lake reminded them of Muckross, while Spring Valley, the rift valley of the San Andreas fault line, reminded them of the pastoral landscape surrounding the Lakes of the Killarney in Ireland. The backdrop to the west was the steep foothills of the Santa Cruz Mountains. They wanted to capitalize on all of these existing features and frame them so they could be enjoyed from the house and garden.
In making design decisions, the Bourns were conservative and preferred English traditional styles for the House and the Garden. Both the Bourns and the Chases were from English ancestry; families that had originally immigrated to America in the late 17th century. They followed classical planning aesthetics and absorbed ideas from many different Country Life publications and also from their travels and past experiences. They enjoyed managing the project themselves, treated it like a business, and watched their costs very carefully because they were maintaining several other properties, including the Empire Mine and Muckross, at the same time they were building Filoli.
Compared to other projects, the Bourns showed amazing focus and restraint in making decisions. They required that the design satisfy their need for privacy and seclusion and provide opportunities to enjoy country life. They repeatedly chose the less elaborate and simpler alternative when presented with multiple design options. The result, almost a century later, is an understated and elegant beauty that draws people from all over the world.