It always depends on your risk tolerance - some people jump out of planes but that's not on my bucket-list. Seriously, have your clients research the Alquist-Prieto earthquake hazards maps prepared by the State and viewable on-line. Some faults are considered 'dormant' but others are still rated to be active even though they haven't had a rupture in recorded history. The Santa Rosa fault just north of Thousand Oaks falls in the active category with displacement along the fault rated as possible.
As a native San Franciscan I still remember reading an article in National Geographic about the San Andreas fault. The writer was speaking to a woman living in Daly City just south of where I lived. When she asked about how she coped living on top of the fault, she pooh-poohed him saying "It isn't under the house, it's out there by the back fence". That's risk tolerance!!