Exterior fire-resistant construction.
All main buildings, excluding accessory buildings that are strictly for agricultural use, shall have all exterior side walls and 75 percent of the front and rear exterior walls below the first floor plate line, excluding doors and windows, shall be constructed of masonry materials as described in division 32, Regulations Applicable to all Districts, section 25.02.712, and in accordance with the city building code, as amended, and fire code, as amended.