In this chapter:
(1) "Historic courthouse" means a county courthouse that is at least 50 years old. The term includes a structure that:
(A) previously functioned as the official county courthouse of the county in which it is located; and
(B) is owned by a municipality.
(2) "Historic courthouse project" means a project to preserve or restore a historic courthouse.
(3) "Historic structure" means a structure that:
(A) is included on the National Register of Historic Places;
(B) is designated as a Recorded Texas Historic Landmark;
(C) is designated as a State Archeological Landmark;
(D) is determined by the Texas Historical Commission to qualify as eligible property under criteria for inclusion on the National Register of Historic Places or for designation as a Recorded Texas Historic Landmark or as a State Archeological Landmark;
(E) is certified by the Texas Historical Commission to other state agencies as worthy of preservation; or
(F) is designated by an ordinance of a municipality with a population of more than 1.5 million as historic.