No factory built housing or factory built commercial structure shall be installed on a building site in this state after the effective date of the regulations adopted pursuant to RCW 43.22.480 unless it is approved and bears the insignia of approval of the department.
(1) Any factory built housing or factory built commercial structure bearing an insignia of approval of the department shall be deemed to comply with any laws, ordinances or regulations enacted by any city or county or any local enforcement agency which govern the manufacture and construction of factory built housing or factory built commercial structures or on-site housing.(2) No factory built housing or factory built commercial structure which has been approved by the department shall be in any way modified prior to, or during installation by a manufacturer or installer unless approval of such modification is first made by the department.1973 1st ex.s. c 22 § 2; 1970 ex.s. c 44 § 2.