For indicating the space economization, Mezzanine can be used in many conditions. Mezzanines are stand alone structures that are normally constructed within a building or other type of open facility. They are typically designed as large square- or rectangular-shaped decks, providing open space directly below the mezzanine. Mezzanines maximize clear space both on top of and below the mezzanine. Mezzanines are available in a number of configurations. Structural mezzanines move open space to the top of the mezzanine and contain shelving or rack units below. Free standing mezzanines do not have these structural reinforcements, but make use of columns to support the mezzanine and the weight of its load.