Buildings systems have historically been over-sized to minimize contractor/designer call-backs. It is widely recognized that this over-sizing leads to excessive chiller and boiler cycling with an attendant reduction in efficiency. The same design approach routinely leads to reduced efficiencies throughout the building systems. The same mentality pervades the operation of building systems. This customarily increases utility costs by at least 20%. This presentation will present specific examples of the deleterious effects of the ”more is better” approach by examining the impact of too much differential pressure across a control valve, too much supply air, and an over-sized pump in a thermal storage system.