means a factory-assembled structure or structure equipped with the necessary service connection and made so as to be readily movable as a unit or units on their own running gear, and designed to be used as a long-term dwelling unit or units either with or without a permanent foundation. Such a structure is, or has been constructed such that it will or may be moved from time to time, but shall specifically not include modular homes. For the purpose of this title, all manufactured houses shall be considered to be single-family dwelling units. All manufactured homes must have a foundation base which shall provide adequate support for the placement of the home in accordance with WAC
296-150B-225 through
296-150B-255 as said sections now exist or are hereafter amended.