This San Francisco couple wanted to add some informal living space to their cozy, 1 story Victorian home. They envisioned a 3 story rear addition, containing 3 stacked spaces: a family room off the existing main level, with a guest room below and a master suite above. The addition could be a radical departure from the traditional main house, with modern flow and detail. The three stories are connected by a light filled open stairway, which functions more as a piece of art.