If the director of the department determines that the standards for factory built housing or factory built commercial structures prescribed by statute, rule or regulation of another state are at least equal to the regulations prescribed under RCW 43.22.450 through 43.22.490, and that such standards are actually enforced by such other state, he or she may provide by regulation that factory built housing or factory built commercial structures approved by such other state shall be deemed to have been approved by the department.