The Siboni Arts and Science Center at the corner of Vallejo and Webster Streets in San Francisco, is a 7-story concrete and steel building which include a 355-seat sloped floor performing arts theater, science labs, flexible classrooms, music and art rooms. Each of the three rooftops was designed as play and assembly space for the students. A 7-story elevator bank ties all levels together. The Siboni project was constructed on the occupied K-12 school campus located in the residential Pacific Heights neighborhood, with sweeping views of the Bay. This was the third project Herrero completed for Schools of the Sacred Heart. Knowing the campus and client well, proved valuable in approaching the challenging site work. A house occupying the site had to be razed, a portion of the hill had to be removed, and underpinnings of an adjacent building were required to 66 feet below grade — one of the deepest excavations in San Francisco’s history. The school's low-to-the-ground stepped architecture specifically abated neighborhood concern that property values would drop and that views of the Bay and Golden Gate Bridge would be obstructed. By successfully enforcing all safety measures, paying close attention to the construction schedule and materials staging, and communicating frequently with owners and neighbors about progress, Herrero effectively managed the challenges of the steep hillside, quiet residential surroundings, and the school operations.