Amends the Property Tax Code. In provisions concerning the Historic Residence Assessment Freeze Law, provides that the fair cash value of the property shall be based on the final determination by the assessment officer, board of review, Property Tax Appeal Board, or court. Provides that, after the expiration of the 8-year valuation period, if the current fair cash value is less than the adjusted base year valuation, then the assessment shall be based on the current fair cash value. Provides that those changes are declarative of existing law.