Buffers. Buffer areas are required between residential and nonresidential development and also between multifamily development, including townhouse development and areas zoned, developed or proposed for single-family dwellings whether part of the same project or on an adjacent tract. For uses within the same project, the Planning Board shall waive this buffer requirement if appropriate transitional uses are employed or if topography eliminates the need for said buffer. No buffer is required if the perimeter property line abuts a roadway and the setbacks, set forth in this article, are adhered to. Where a buffer is required along a side or rear property line, a strip of land at least 20 feet wide in the yard or setback area shall be designated as a buffer area. Buffer areas shall adjoin residential property lines and be of uniform width. The buffer area shall contain a landscape screen consisting of a six-foot-high visual barrier of plantings of suitable materials set in a double row, staggered and spaced to accomplish this purpose or a landscaped earthen berm parallel to the lot line and set back an appropriate distance, said berm to be improved with suitable landscaping treatment. Plant materials, spacing and location of the plant materials as set forth elsewhere in the developmental ordinances of the Township, shall be controlling.