225 ILCS 440/6.01
No sign may be erected which exceeds 1,200 square feet in area, 30 feet in height and 60 feet in length, including border and trim, but excluding ornamental base or apron, supports and other structural members. Except with respect to the repair, rebuilding, or replacement of any sign lawfully erected before January 1, 1993, no sign may be erected after the effective date of this amendatory Act of 1992 in any county with a population under 2,000,000 that exceeds 800 square feet in area, excluding extensions and cut-outs; the extensions and cut-outs may account for no more than an additional 20% in sign surface area. The maximum size limitation shall apply to each side of a sign or sign structure. A maximum of 2 signs may be erected in a facing, in which event the facing shall be deemed to be one sign, the size of which may not exceed the dimensions listed in this Section. Signs may be double faced or be placed back to back or V-type or triangular, provided that the angle between sign faces shall not exceed 90 degrees. The area shall be measured by the smallest square, rectangle, triangle, circle or combination thereof which will encompass the entire sign.
225 ILCS 440/6.01