Except as provided in subsection (b) of this section, each hotel or motel with 10 or more units for which a contract for construction is executed after July 1, 1989, shall have installed a fast response residential fire sprinkler system that is intended: to detect and control a fire automatically; to provide improved protection against injury, loss of life, and property damage; to maintain survivable conditions in the room of fire origin; and to improve the chance for occupants to escape or be evacuated. A hotel or motel need not install a fast response residential fire sprinkler system if: the hotel or motel is a one or two story building; and all occupants are able to exit directly to the exterior of the building and not only to a central corridor through an approved exit door, as those terms are used in the most recent edition of the National Fire Protection Association Life Safety Code adopted by the State Fire Prevention Commission.