This Act shall not apply in any instance where the proposed erection, addition to or replacement of a structure is located in an area for which airport approach regulations are effective under "An Act relating to airport zoning", approved July 17, 1945, as amended from time to time.
This Act shall not be construed to require any change in height or location of any structure in existence or in the process of construction on the effective date of this Act.
620 ILCS 30/11