30 ILCS 500/40-55

Each lease must provide for actual or liquidated damages upon the lessor's failure to make improvements agreed upon in the lease. The actual or liquidated damages shall consist of a reduction in lease payments equal to the corresponding percentage of the improvement value to the lease value. The actual or liquidated damages shall continue until the lessor complies with the lease and the improvements are certified by the chief procurement officer and the leasing State agency.