Energy models are mathematical representations of processes and systems within a building. The purpose of an energy model is to create an accurate view of how and when energy is consumed within a facility. Models can be applied broadly across the entire building, or focused upon a single piece of equipment. Equilibrium uses information collected from on-site studies, or engineering drawings, to develop and refine the model, and then applies cost data to the conservation measures being studied. Modelling can be applied to the preliminary design of new buildings, or to existing systems and processes. The end result is a better understanding of how a change in process, or investment in energy conservation, will affect the bottom line.