All multi-unit residential Building exteriors shall be brick, stucco, stone, tile, metal panels or fiber cement siding. With the exception of brick or stone which may be used on the entire Building exterior, no single material shall comprise more than 60 percent of a Building’s exterior. Where stucco, tile, metal panels or fiber cement siding are used, at least 20 percent of the Building’s exterior shall be brick or stone. Wood and vinyl may be used as trim, soffits and/or accent materials only.