Mezzanine
（重定向自Mezzanine floor）
In architecture, a mezzanine or entresol is a raised platform that is independent of a building structure and is supported by columns.
Mezzanine flooring can create additional floors of space for a variety of different uses including storage or extra office space. Mezzanine floors are a very quick and cost-effective way to create new space without the expense and inconvenience of relocation.