Yes, you better have an elevator machine room as you don't want your controllers, sheaves, cables, flyball governors etc... be in the open to expose the public to these potential hazards and have some schizophrenic nuts tinker with the equipment. Also get a copy of the American National Standard Safety Code for Elevators, Dumbwaiters, Escalators and Moving Walks ANSI A17.1 published by ASME.