This invention relates to a new and useful device for monitoring the heating and cooling energy consumed by a single unit of a multi-unit apartment or office building. The monitoring circuit is responsive to a thermostat located in each unit as well as the speed of a blower; said blower being used to force the heated or cooled air into the unit. The monitoring circuit is comprised of an integrating circuit coupled to the thermostat and/or fan speed circuit. A pulse generator is electrically coupled to the integrating circuit; the pulse generator generates a pulse after a predetermined amount of current flows into the integrating circuit. The extended pulse is then transmitted to amplifier means which in turn transmits said signal to a pulse counter.