No contract may be made or expense or liability incurred by the board, by any member or committee of the board, or by any person for or in its behalf, notwithstanding the expenditure may have been ordered by the board, unless an appropriation therefor has been previously made. Neither the board, nor any member or committee, officer, head of any department or bureau, or employee thereof may during a fiscal year expend or contract to be expended any money, incur any liability, or enter into any contract which by its terms involves the expenditure of money for any of the purposes for which provision is made in the annual budget, in excess of the amounts appropriated in the annual budget. Any contract, verbal or written, made in violation of this Section is void as to the board, and no moneys belonging to the board may be paid on that contract. This Section does not prevent the making of lawful contracts for the construction of buildings, the purchase of insurance, or the leasing of realty, space and equipment, the terms of which conform with the requirements of this Act, or the making of lawful employment contracts and purchase orders the terms of which exceed one year.
     The board may, however, lease from any public building commission created pursuant to the provisions of the “Public Building Commission Act”, approved July 5, 1955, as now or hereafter amended, any real or personal property for the purpose of securing office or other space for its administrative functions or for community college purposes for any period of time not exceeding 40 years, and such lease may be made and the obligation or expense thereunder incurred without making a previous appropriation therefor, except as otherwise provided in Section 7-1.1 of this Act.