Special side and rear yard regulations in single-family residential districts. Notwithstanding the otherwise applicable side and rear yard regulations established for principal structures and uses by the district regulations of this chapter, detached accessory structures and uses located within the rear 20% of the lot shall not be required to maintain an interior side or rear yard in excess of five feet in any single-family residential district; provided, however, that this special regulation shall not apply to residential recreational facilities or antennas and antenna support structures, and provided further, however, that no accessory structure or use, or combination of such structures or uses, located within an otherwise required side or rear yard pursuant to this subsection shall occupy more than 30% of such required yard. Notwithstanding the foregoing limitations, parking areas within single-family residential districts may be located in any required yard.