The owner is erecting the building as lessee under _________ certain long-term leases covering the premises upon which the building is to be erected, and the subcontractor agrees and stipulates that it is a condition of this contract that no lien shall arise or be claimed on account of this contract or on account of any work done or material furnished under this contract as against the title or interest of the lessors, or any of them, in the premises. The subcontractor waives any and all right of or claim to a lien upon the demised premises so far as the lessors' interest in the premises is concerned, and that any lien that may arise or be claimed under this contract shall attach only to the leasehold interests of the lessee in the demised premises, and the subcontractor agrees to cause waivers of lien as against the interest of the lessors in the demised premises to be delivered to the owner duly executed by its subcontractors, or others, furnishing labor, services or material in and about the erection of the building pursuant to this contract, which waivers shall be executed and delivered to the owner before the subcontractor or others shall enter upon the performance of the work or the furnishing of the material.