The authority and any person are hereby authorized to enter into a lease or leases for the use and occupancy of any or all property of the authority or for the use and occupancy of any space in or all of any buildings or facilities constructed by the authority under the provisions of this article; provided, that the proposed use by any such lessee or lessees shall be in furtherance of the purpose for which the authority is created; provided further, that an adequate rental is established in said lease or leases. Any executive head of any agency, board, commission, public corporation, bureau or department of the state is hereby separately authorized to enter into any said lease with the authority.

No free space shall be available to any person on any of the property or in any of the buildings, facilities and structures of the authority so long as the principal of or interest on any bonds, including refunding bonds, issued by the authority remains unpaid. If at any time there is or is about to be vacant space on the property or in the buildings, facilities or structures constructed by the authority and there is no person available to rent such space for the purpose for which the authority is created, then, but only in such event, in order to prevent default in its bonds, the authority is hereby authorized to enter into leases with any person for any lawful purposes pursuant to and subject to such rules and regulations as to such occupancy as may be adopted by the authority; provided, that the use of such facilities by such tenants shall not interfere with the use of the premises by other tenants who are occupying same in furtherance of the purpose for which the authority is created; provided further, that any such leases shall be based upon a rental rate, established by the authority, commensurate with the then current commercial rates for similar facilities and space of like character in the City of Birmingham, Jefferson County, Alabama. Any such lease shall not be for the purpose of competing with private enterprise or for lending public credit, but shall be solely for the use and benefit of the holders of the authority's bonds to avoid default thereon and to insure the prompt payment of the principal thereof and interest thereon when due.