Wash. Rev. Code § 91.08.200
If the land and buildings belong to different parties, or if the title to the property be divided into different interests by lease or otherwise, the damage done to each of such parties or interests may be separately found by the jury or court on the written request of any party. And in making such findings the jury or court shall first find and set forth the total amount of the damage to said lands and buildings and all premises therein, estimating the same as an entire estate and as if the same were the sole property of one owner in fee simple; and they shall then apportion the damages so found among the several parties entitled to the same in proportion to their several interests and claims. But no delay in ascertaining the amount of compensation shall be occasioned by any doubt or contest which may arise as to the ownership of the property or any part thereof, or as to the extent of the interest of any defendant in the property to be taken or damaged, but in such case the jury or court shall ascertain the entire compensation or damage that should be paid for the property and the court may thereafter require adverse claimants to interplead so as to fully determine their rights and interests in the compensation so ascertained, and may make such order as may be necessary in regard to the deposit or payment of such compensation and the division thereof.
RCW 91.08.200