UCs and CSUs list different costs of attendance for students living with parents, and students living on their own (some campuses may also distinguish between campus dorms and nearby off-campus housing). If you try the net price calculators with different housing assumptions in the selection, you can see how that affects financial aid.
Because UCs (but not CSUs) adjust financial aid based on an assumed cost difference between living on your own versus living with parents, it may not save that much money living with your parents if you will be getting the maximum (EFC = $0) financial aid package at a UC. Savings or lack thereof would be based on whether your actual living expenses living on your own or with your parents are higher or lower than the estimates that the schools use.