First floor

A storey (British English) or story (American English; see spelling differences) is any level part of a building with a floor that could be used by people (for living, work, storage, recreation, etc.). The plurals are "storeys" and "stories" respectively.

The terms "floor", "level", or "deck" are used in a similar way, except that it is usual to talk of a "24-stor[e]y building", but "the 13th floor". The floor at ground or street level is called the "ground floor" in many places. The words "storey" and "floor" exclude levels of the building that are not covered by a roof, such as the terrace on the top roof of many buildings.

Houses commonly have only one or two floors. Buildings are often classified as low-rise, mid-rise and high-rise according to how many levels they contain, but these categories are not well-defined. The tallest skyscraper in the world, Burj Khalifa, has 163 floors.

The height of each storey is based on the ceiling height of the rooms plus the thickness of the floors between each pane. Generally this is around 10 feet (3 m) total; however, it varies widely from just under this figure to well over it. Storeys within a building need not be all the same height—often the lobby is taller, for example. Additionally, higher levels may have less floor area than the ones beneath them (e.g, the Willis Tower).

In English, the principal floor or main floor of a house is the floor that contains the chief apartments; it is usually the ground floor, or the floor above. In Italy the main floor of a home is usually above the ground level, and may be called the piano nobile ("noble floor").

The attic or loft is a storey just below the building's roof; its ceiling is often pitched and/or at a different height than that of other floors. A penthouse is a luxury apartment on the topmost storey of a building. A basement is a storey below the main or ground floor; the first (or only) basement of a home is also called the lower ground floor.

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