No building, structure, improvement, or premises shall be used, and no building, structure, or improvement shall be erected, constructed, altered, enlarged, or maintained on any lot or parcel in zone S which is designed, arranged, or intended to be used for any purpose other than as follows:
A. For public educational purposes, including without limitation the purposes specified by Education Code section 40041. Such purposes, however, shall not include any residential, commercial, industrial or other nonpublic use or development on any lot or parcel, or portion thereof, determined by the governing board of the Beverly Hills Unified School District not to be needed for public school purposes unless the zoning of such lot or parcel is changed to permit such use or development in accordance with Government Code section 65852.9;