(65 ILCS 5/11-13-4) (from Ch. 24, par. 11-13-4)
    Sec. 11-13-4. In municipalities of 500,000 or more population, the regulations authorized by this Division 13 may be varied in their application only by the board of appeals of the municipality, subject to the power of the corporate authorities to prohibit, in whole or in part, the granting of variations in respect to the classification, regulation and restriction of the location of trades and industries and the location of buildings designed for specified industrial, business, residential and other uses. Variations shall be permitted by the board of appeals only when they are in harmony with the general purpose and intent of the regulations and only in cases where there are practical difficulties or particular hardship in the way of carrying out the strict letter of any of those regulations relating to the use, construction, or alteration of buildings or structures or the use of land. In its consideration of the standards of practical difficulties or particular hardship, the board of appeals shall require evidence that (1) the property in question cannot yield a reasonable return if permitted to be used only under the conditions allowed by the regulations in that zone; and (2) the plight of the owner is due to unique circumstances; and (3) the variation, if granted, will not alter the essential character of the locality. A variation shall be permitted only if the evidence, in the judgment of the board of appeals, sustains each of the 3 conditions enumerated. The corporate authorities may provide general or specific rules implementing, but not inconsistent with, the rules herein provided to govern determinations of the board of appeals. A decision of the board of appeals shall not be subject to review, reversal or modification by the corporate authorities but shall be judicially reviewable under the provisions of Section 11-13-13.
(Source: P.A. 82-430.)