65 ILCS 5/11-13-12
An appeal to the board of appeals may be taken by any person aggrieved or by any officer, department, board, or bureau of the municipality. The appeal shall be taken within 45 days of the action complained of by filing, with the officer from whom the appeal is taken and with the board of appeals a notice of appeal, specifying the grounds thereof. The officer from whom the appeal is taken shall forthwith transmit to the board all the papers constituting the record upon which the action appealed from was taken.
An appeal stays all proceedings in furtherance of the action appealed from, unless the officer from whom the appeal is taken certifies to the board of appeals, after the notice of appeal has been filed with him, that by reason of facts stated in the certificate a stay would, in his opinion, cause imminent peril to life or property. In this event the proceedings shall not be stayed otherwise than by a restraining order which may be granted by the board of appeals or by a circuit court on application and on notice to the officer from whom the appeal is taken, and on due cause shown.
The board of appeals shall fix a reasonable time for the hearing of the appeal and give due notice thereof to the parties and decide the appeal within a reasonable time. Upon the hearing, any party may appear in person or by agent or by attorney. The board of appeals may reverse or affirm, wholly or partly, or may modify the order, requirement, decision, or determination as in its opinion ought to be made in the premises and to that end has all the powers of the officer from whom the appeal is taken.
65 ILCS 5/11-13-12