The following standards are advisory, rather than mandatory:

(1) Space heating systems should be designed to be capable of providing the following minimum space ambient temperatures:

(a) classrooms, offices, music rooms, auditoriums, multi-purpose rooms, libraries, cafeterias, toilet, and similar rooms -- 68°F at four feet from the floor;

(b) locker rooms and showers -- 75°F at four feet from the floor;

(c) gymnasiums -- 65°F at four feet from the floor.