(a) This chapter does not apply to the construction of a structure in a municipality that has in effect a nationally recognized model building code governing the construction if the building code requires at least one one-hour fire-resistive means of escape with a total width equal to or greater than the total exit width required under this chapter for a structure of three or more stories.
(b) This chapter does not apply to a grain elevator constructed of:
(1) steel;
(2) steel and concrete; or
(3) wood if fewer than five persons are employed at the grain elevator.

(c) This chapter does not apply to a county courthouse that:
(1) was constructed before September 1, 1989; and
(2) is located in a county with a population of less than 50,000.