Indiana Code Title 36. Local Government § 36-7-11-6

Sec. 6.  (a) The commission shall conduct a survey to identify historic buildings, structures, and sites located within the unit.  Based on its survey, the commission shall submit to the legislative body a map describing the boundaries of a historic district or historic districts.  A district may be limited to the boundaries of a property containing a single building, structure, or site.  The map may divide a district into primary and secondary areas.

(b) The commission shall also classify and designate on the map all buildings, structures, and sites within each historic district described on the map.  Buildings, structures, and sites shall be classified as historic or nonhistoric in the manner set forth in subsections (c) and (e).

(c) Buildings, structures, and sites classified as historic under this section must possess identified historic or architectural merit of a degree warranting their preservation.  They may be further classified as:

(d) In lieu of the further classifications set forth in subsection (c), the commission may devise its own system of further classification for historic buildings, structures, and sites.

(e) Nonhistoric buildings and structures are those not classified on the map as historic under subsection (b).