Section 1017 addresses elevators, escalators, platform lifts, and other vertical conveyances. Elevators must be provided in all occupancies with more than one story, except one- and two-story buildings and certain townhouses. Emergency operation is required, with manual operation during power failures permitting elevator descent to a floor and opening doors. Elevators must have adequate capacity to carry occupant loads, typically 10 persons or 2,500 pounds for standard residential elevators. Elevator machines must be located in a separate machine room above the elevator hoistway with proper fire-resistance and ventilation. Shaft enclosure must have 1-hour or 2-hour fire-resistance rating depending on building type. Elevator doors must close safely without trapping occupants. Escalators must be protected with automatic stopping at stair end, clear width, and slip-resistant steps. Platform lifts provide vertical accessibility in spaces where elevators are not feasible, with capacity for wheelchairs. Emergency exit stairs in elevator shafts provide secondary exit during elevator failures. Hoistways must be enclosed to prevent debris falling and to contain fire. Lighting in elevator cars and hoistways must be adequate for safe operation. Emergency voice communication must be provided in elevators for occupants to call for assistance.