Section 35 ILCS 200/10-70 - Computation of valuation(a) Upon receipt of the certificate of rehabilitation, the assessment officer shall determine the base year valuation and shall make a notation on each statement of assessment during the 8-year valuation period and the adjustment valuation period that the valuation of the historic building shall be based upon the issuance of a certificate of rehabilitation.(b) Upon revocation of a certificate of rehabilitation, the assessment officer shall compute the assessed valuation of the building on the basis of the then current fair cash value.(c) An historic building receiving a certificate of rehabilitation shall not be eligible for the homestead improvement exemption during the 8-year valuation period and adjustment valuation period.