Ill. Admin. Code tit. 92, § 16.180 – Variances

a) General. Any person wishing to erect or increase the height of any structure or permit any vegetation or use of his/her property not in accordance with this Part must obtain a variance from the Division.
b) Marking and Lighting. Any variance granted by the Division may be so conditioned as to require the owner of the structure or vegetation to permit, at the expense of the owner, the installation, operation and maintenance of markers and lights as may be required to indicate to pilots the presence of the structure or vegetation.
c) In making a determination to allow a variance, the Division will consider, but is not limited to considering:
1. 1) the proximity of the hazard to the normal flight path or traffic patterns at the airport;
2. 2) the proximity of other non-conforming uses, structures or vegetation that would impair the use of the airport;
3) the height of the object;
4) the volume of air traffic at the airport;
5) the type of aircraft using the airport;
6) the type of navigational aids used at the airport;
7) the length and width of existing runways; and
8) the plans for future expansion of the airport.
1. d) A decision to grant or deny a variance will be made by the Division within 30 calendar days after receipt of the notice (see Section 16.160) or within 30 calendar days after receipt of supplemental information (see Section 16.160(c)(2)(C)). The person or sponsor may appeal any decision made by the Division (see Section 16.190).
Variances would be granted when it is found that a literal application or enforcement of this Part will result in practical difficulty or unnecessary hardship and the relief granted is not contrary to the public interest but would do substantial justice and will be in accordance with the spirit of the Act. (Section 24 of the Act)