625 ILCS 5/1-145.01

A self-contained motor vehicle, not used commercially, designed or permanently converted to provide living quarters for recreational, camping or travel use, with direct walk through access to the living quarters from the driver's seat. Such vehicles must include at least four of the following: a) A cooking facility with an on-board fuel source; b) A gas or electric refrigerator; c) A toilet with exterior evacuation; d) A heating or air conditioning system with an on-board power or fuel source separate from the vehicle engine; e) A potable water supply system that includes at least a sink, a faucet, and a water tank with an exterior service supply connection; f) A 110-125 volt electric power supply.