35 ILCS 200/10-60
It is the duty of the titleholder of record or the owner of the beneficial interest of any historic building which has been issued a certificate of rehabilitation, to file with the chief county assessment officer, on or before January 31 of each year, an affidavit stating whether there has been any change in the ownership or use of such property, the status of the owner-occupant, or, in the case of a cooperative, whether there has been a change in the use of the property or a change in the cooperative form of ownership. If there has been such a change, the nature of this change shall be stated. Failure to file such an affidavit shall, in the discretion of the chief county assessment officer, constitute cause to revoke the certificate of rehabilitation. The chief county assessment officer shall furnish to the owner a form for the affidavit wherein the owner may state whether there has been any change in the ownership or use of the property or the status of the owner. If the chief county assessment officer determines that the historic building is no longer used as an owner-occupied single family residence or an owner-occupied multi-family residence, or that there has been a sale or transfer for value of the historic building other than to the first owner-occupant after the issuance of a certificate of rehabilitation, or that the historic building no longer meets the definition of a cooperative, he or she shall revoke the certificate by written notice to the taxpayer of record, and shall send a copy of that notice to the Department.
35 ILCS 200/10-60