Office in MF-D not facing and having its main entrance on Broadway or the Austin Highway, provided such office (1) is compatible and harmonious with the surrounding neighborhood, (2) is to be located in a preexisting structure which contains no more than one thousand five hundred (1,500) square feet of enclosed area, (3) the property upon which the structure is located is contiguous to a property zoned B-1, B-2 or B-3, (4) some portion of the property across the street from the subject property must be zoned B-1, B-2 or B-3 if the property across the street from the subject property is in Alamo Heights, (5) the office is for a use authorized in the schedule of permitted uses for offices in section 3-8 of this zoning code, (6) the structure and property comply with the parking, landscape, setback and other requirements of the zoning code applicable to O-1, and (7) the specific use permit requested promotes the health, safety and general welfare of the residents of the city.