“Special valuation for historic properties” or “special valuation” means the local option program which when implemented makes available to property owners a special tax valuation for rehabilitation of historic properties under which the assessed value of an eligible historic property is determined at a rate that excludes, for up to 10 years, the actual cost of the rehabilitation. (Chapter 84.26 RCW). (Ord. 2069 § 2 (Exh. B), 2011).