Illinois Administrative Code
Title 71 - PUBLIC BUILDINGS, FACILITIES AND REAL PROPERTY
Part 600 - ILLINOIS ENERGY CONSERVATION CODE
Subpart C - PRIVATELY FUNDED COMMERCIAL FACILITIES
Section 600.320 - Local Jurisdiction

a) Construction projects involving privately funded commercial facilities and for which a municipality or county requires a building permit must comply with the Illinois Energy Conservation Code if the project involves new construction, addition, alteration, renovation or repair. In the case of any addition, alteration, renovation or repair to an existing commercial structure, the Code as described by this Subpart C applies only to the portions of that structure that are being added, altered, renovated or repaired. [20 ILCS 3125/20(a)]

b) The local authority having jurisdiction (AHJ) shall establish its own procedures for enforcement of the Illinois Energy Conservation Code. The AHJ is authorized to enforce a building code that differs with the Code as described in this Subpart C, but any standards applied by an AHJ must be at least as stringent as the Code as described in this Subpart C.

c) A unit of local government that does not regulate energy efficient building standards is not required to adopt, enforce or administer the Code; however, any energy efficient building standards adopted by a unit of local government must comply with the Act. If a unit of local government does not regulate energy efficient building standards, any construction, renovation or addition to buildings or structures is still subject to the provisions contained in the Act. [20 ILCS 3125/20(d)]