Such lease may be entered into without making a previous appropriation for the expense thereby incurred; provided, however, that if the board undertakes to pay all or any part of the costs of operating and maintaining the property of a public building commission as authorized in this Section, such expenses of operation and maintenance shall be included in the annual budget of such board annually during the term of such undertaking.
In addition, the board may undertake, either in the lease with a public building commission or by separate agreement or contract with a public building commission, to pay all or any part of the costs of maintaining and operating the property of a public building commission for any period of time not exceeding 40 years.
110 ILCS 805/7-1.1