As used in this part, the terms set out hereinbelow are defined as follows:
(1) “Person” means an individual, corporation, partnership, business, trust, unincorporated organization, association or joint stock company; and
(2) “Substantial completion” means that degree of completion of a project, improvement, or a specified area or portion thereof (in accordance with the contract documents, as modified by any change orders agreed to by the parties) upon attainment of which the owner can use the same for the purpose for which it was intended; the date of substantial completion may be established by written agreement between the contractor and the owner.