What was once a growing trend, green building and sustainable design—has now become mainstream in building design and construction. Green building is typically associated with environmental responsibility. However, an often-overlooked objective of green building is the bottom-line motivation of the owner to realize energy savings through increased efficiency in building systems. Thus, the hallmark of any green building project is the ability to verify the performance expectations of the owner through a verification process of the building energy systems commonly known as commissioning.