We take total energy usage by building (electricity, Steam, Nat Gas and Chilled Water) convert all of those to one common unit, MMBTU (million British Thermal Units) and after adjusting for the weather differences between years, compare each building's annual usage with the year before.  We then convert the change into a percentage and then rank all eligible buildings by percentage saved.  The top four in each category win first through fourth.     Having won in FY13 does not disqualify you from winning in the future.  The goal is to encourage individual contributions to saving energy.   Mike Marquissee