From Marin County Main access to San Francisco from the north is via the Golden Gate Bridge. Follow signs to Lombard Street. Turn right at the next street, which is Chestnut. SFAI is 1 block farther down Chestnut, on the left side of the street. The San Francisco Art Institute is located in a residential neighborhood.
Parking is available on all of the streets immediately surrounding the school.
For me, that summed it up.