PROBLEM TO BE SOLVED : To provide a real-estate rental property rental method allowing a renter of a real estate to recover a facility investment expense and actively promoting electric appliances with small power consumption.SOLUTION : A real-estate rental property rental method includes the steps of : calculating a first electricity usage charge being an average electricity usage charge in a predetermined period for an electric appliance preinstalled in a real-estate rental property; calculating a second electricity usage charge being an electricity usage charge in the predetermined period in the case of changing the preinstalled electric appliance to an electric appliance with a smaller power consumption; calculating the difference between the first and second electricity usage charges; and calculating a part of the difference as a burden charge to be paid by the renter of the real-estate rental property.COPYRIGHT : (C)2013, JPO&INPIT