The first step of an energy conservation program is to monitor energy consumption. A system is explained that, in order to determine which buildings are energy efficient (considering all types of energy that a building might use), monitors total energy consumption. All such consumptions can be reduced to a common denominator: Barrels of Energy (BOE) or British Thermal Unit (BTU). The conversion factors are given for both calculations. To demonstrate how the procedure operates, figures of energy consumption (oil, gas, and electricity) are given for six fictitious buildings for two different years. Worksheets are provided to use in calculating which of the buildings is operating with the greatest degree of energy efficiency. (MLF)