A machine room is an area where the elevator drive unit, controller and main disconnect switches are located. Typically for residential elevators, a machine room will be located on the lowest landing as close as possible to the elevator hoistway.

The Machine Room-Less (MRL) elevator is now available because advanced motor technology has reduced the size of electric motors used with traction equipment. These newly designed permanent magnet motors (PMM) allow the manufacturers to locate the machines in the hoistway overhead, thus eliminating the need for a machine room, typically over the hoistway. A typical traction elevator requires a sheave-to-rope ratio of 40:1 – in other words, a sheave 40 times the diameter of the hoist rope. Smaller ratios such as 16:1 might be achieved with the MRL hoisting methods. When these types of smaller ratios are achieved, a flexible high strength hoist rope is used to provide the smaller 16:1 ratio. The grooves are shaped to grip the hoist ropes.