For a downtown Chicago high-rise built in 1969, energy auditing made a huge difference in the amount of energy consumed. Before the energy audit in 2008, the building's energy use intensity (EUI) was 123 kBtu/ft2 yr (exclusive of independent, separately metered condominium usage that includes fan coil fans, refrigerators, stoves and plug loads). After implementing the project's recommendation, the building's EUI decreased to 55 kBtu/ft2 yr, which is a 55% reduction in energy consumption.