(a) Except as provided in subsections (b) and (d), nothing in this section shall be construed as requiring registration for the purpose of practicing architecture, engineering or landscape architecture by a person; provided, that the person does not use the appellation “architect,” “engineer” or “landscape architect,” an appellation that compounds, modifies or qualifies the word “architecture,” “engineering” or “landscape architecture,” or that gives or is designed to give the impression that the person using those words is an architect, engineer or landscape architect.

(b) It is unlawful for any person other than a registered architect or engineer to prepare plans and specifications for any building or structure other than the following:

(1) Structures classified as business, factory-industrial, hazardous, mercantile, residential and storage occupancies, as those occupancies are defined in the 1985 edition of the Standard Building Code, that are:

(A) Less than three (3) stories in height; and

(B) Less than five thousand square feet (5,000 sq. ft.) in total gross area;

(2) One-family and two-family dwellings and domestic outbuildings appurtenant to those dwellings;

(3) Farm buildings not designed or intended for human occupancy; or

(4)

(A) Signs that do not exceed either of the following limits:

(i) Any portion of the sign is twenty feet (20′) or more above the ground level; or

(ii) Any portion of the sign is fifteen feet (15′) or more above the ground level, if the sign has more than one hundred twenty square feet (120 sq. ft.) in total sign face area;

(B) Subdivision (b)(4)(A) shall not apply if, in the opinion of the local government building official, failure of the support system for the sign is likely to cause harm to people or property.

(c) Nothing in this section shall prevent any awarding authority, public or private, from requiring the services of a registered architect, engineer or landscape architect for any project.

(d) Any person, firm, company, business, corporation or other entity that was organized and doing business other than business regulated in this chapter that was organized and doing business prior to January 1, 1967, and whose corporate name includes the appellation “engineer” or an appellation that compounds, modifies or qualifies the word “engineering,” may continue to use that corporate name and shall not be required to register pursuant to this chapter. This section shall not be construed to authorize those entities to engage in the practice of architecture, engineering or landscape architecture without registering pursuant to this chapter.