Except as hereinafter set forth, no buildings shall be erected to a height in excess of two and one-half stories or in excess of 35 feet. In a U3 District, apartment houses may be erected to a height of four stories but no greater than a height of 50 feet. If a height district limitation is specifically set forth in another chapter of this Planning and Zoning Code, the provisions set forth in the specific district chapter shall prevail over the provisions contained in this section.