Except as otherwise specified in the case of a combining district, and except for mobilehome parks as regulated by Chapter 17.52 of this title, every use in an R-S district shall be on a building site having a median lot width not less than fifty (50) feet, and an area not less than five thousand (5,000) square feet. A corner building site shall have a median lot width of not less than sixty (60) feet. (Prior gen. code § 8-28.5)