Sec. 12. (a) "Public project" means the process of designing, constructing, reconstructing, altering, or renovating a public building, an airport facility, a sewer, a drain, or another structure or improvement that is paid for out of:
(1) a public fund; or
(2) a special assessment.
(b) The term includes either of the following:
(1) A process described in subsection (a) relating to a building or structure leased by a public agency under a lease containing an option to purchase.
(2) A public improvement to real property owned by a public agency.
(c) The term does not include the process of designing, constructing, altering, or repairing a public highway (as defined in IC 9-25-2-4).