Multifamily Projects. All multifamily projects with 6 or more units shall be required, prior to the issuance of a certificate of occupancy and/or business license, to construct a wall along the rear and the side yard boundaries of the development. The purpose of the wall is to mitigate adverse noise and land use impacts. Therefore, the wall, the height of which shall be determined by the Zoning Administrator, Planning Commission or City Council, depending upon the required level of processing, shall be constructed from the following materials: masonry, pre-cast, cast-in-place, or brick. A front wall may also be required for screening purposes.