65 ILCS 5/11-84-2
Such an ordinance shall define the location of the proposed sidewalk or the sidewalk to be repaired with reasonable certainty, shall prescribe its width, the materials of which it is to be constructed and the manner of its construction, and may provide that the materials and construction shall be under the supervision of and subject to the approval of an officer or board of officers of the municipality to be designated in the ordinance.
The ordinance shall require all owners of lots, blocks, tracts, or parcels of land touching the line of a proposed sidewalk to construct or repair a sidewalk in front of or touching upon their respective lots, blocks, tracts, or parcels of land in accordance with the specifications of the ordinance, within 30 days after the mailing of notice of the passage of the ordinance, addressed to the party who last paid the general taxes on the respective lots, blocks, tracts, or parcels. In default thereof the municipality may furnish the materials and construct or repair the sidewalk in accordance with the ordinance, or may enter into a contract for the furnishing of the materials and the construction or repair of the sidewalk as hereinafter provided in this Division 84. The cost of such part thereof as may be fixed in the ordinance may be collected as hereinafter provided in this Division 84. The municipality may issue vouchers bearing not to exceed 6% interest annually in payment of these sidewalks, payable solely out of the special tax provided for in this Division 84 when the tax is collected.
65 ILCS 5/11-84-2