Four criteria must be met for special valuation under this act. The property must:

(1) Be an historic property;

(2) Fall within a class of historic property determined eligible for special valuation by the local legislative authority under an ordinance or administrative rule;

(3) Be rehabilitated at a cost which meets the definition set forth in RCW 84.26.020(2) within twenty-four months prior to the application for special valuation; and

(4) Be protected by an agreement between the owner and the board as described in RCW 84.26.050(2).