Unless the context clearly requires otherwise, the definitions in this section apply throughout this chapter.

(1) "Historic property" means real property together with improvements thereon, except property listed in a register primarily for objects buried below ground, which is:

(a) Listed in a local register of historic places created by comprehensive ordinance, certified by the secretary of the interior as provided in P.L. 96-515; or

(b) Listed in the national register of historic places.

(2) "Cost" means the actual cost of rehabilitation, which cost shall be at least twenty-five percent of the assessed valuation of the historic property, exclusive of the assessed value attributable to the land, prior to rehabilitation.

(3) "Special valuation" means the determination of the assessed value of the historic property subtracting, for up to ten years, such cost as is approved by the local review board.

(4) "State review board" means the advisory council on historic preservation established under chapter 27.34 RCW, or any successor agency designated by the state to act as the state historic preservation review board under federal law.

(5) "Local review board" means a local body designated by the local legislative authority.

(6) "Owner" means the owner of record.

(7) "Rehabilitation" is the process of returning a property to a state of utility through repair or alteration, which makes possible an efficient contemporary use while preserving those portions and features of the property which are significant to its architectural and cultural values.