Each principal building shall be separated by 30 feet from any other principal building. In cases of rear-to-rear or rear-to-side configuration, the rear of a principal building shall be separated by 45 feet and buffered from the rear or side of any other principal building. The buffer strip shall be a minimum of 15 feet wide, shall not overlap with any required yard, and shall meet the standards of § 155-27.1C(5)(c) of Chapter 155, Subdivision and Land Development.