A buffer wall may be permitted with specific approval by the Planning and Zoning Commission and City Council, when it can be shown that a traditional landscaped buffer is not feasible. A buffer wall shall be a minimum of six (6) feet in height; constructed of a permanent low maintenance material such as concrete block, cinder block, brick, concrete, precast concrete, tile block, etc.; the wall shall be designed by an architect or engineer for both structural adequacy and aesthetic quality.