65 ILCS 5/11-14-1

In addition to existing powers and to the end that adequate light, pure air, or safety may be secured and that congestion of public streets may be lessened or avoided, the corporate authorities in each municipality have power by ordinance to establish, regulate, and limit the building or set-back lines on or along any street, traffic way, drive, or parkway or storm or floodwater runoff channel within the municipality, as may be deemed best suited to carry out these purposes. The powers given by this Division 14 shall not be exercised so as to deprive the owner of any existing property of its use or maintenance for the purpose to which it is then lawfully devoted.