A storey (Commonwealth English) or story (American English), is any level part of a building with a floor that could be used by people (for living, work, storage, recreation, etc.). Plurals for the word are storeys (UK, CAN) and stories (US).
The terms floor, level, or deck are used in similar ways as storey (e.g., "the 16th floor", "double-decker"). However, when referring to an entire building, it is more usual to use storey or story (e.g., "a 16-storey building"). The floor at ground or street level is called the ground floor (i.e. it needs no number); the floor below ground is called basement, and the floor above ground is called "first" in many regions. However, in some regions, like the US, ground floor is synonymous with first floor, leading to differing numberings of floors, depending on region – even between different national varieties of English.
The words storey and floor normally exclude levels of the building that are not covered by a roof, such as the terrace on the rooftops of many buildings. Nevertheless, a flat roof on a building is counted as a floor in other languages, for instance in Dutch, literally "roof-floor", simply counted one level up from the floor number that it covers.
A two-storey house or home extension is sometimes referred to as double-storey in the UK, while one storey is referred to as single-storey.
Overview Houses commonly have only one or two floors, although three- and four-storey houses also exist. 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. A single-storey house is often referred to, particularly in the United Kingdom, as a bungalow. The tallest skyscraper in the world, the Burj Khalifa, also has the greatest number of storeys with 163.
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 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. One review of tall buildings suggests that residential towers may have 3.1 m (10 ft 2 in) floor height for apartments, while a commercial building may have floor height of 3.9 m (12 ft 9.5 in) for the storeys leased to tenants. In such tall buildings (60 or more storeys), there may be utility floors of greater height.
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 was traditionally above the ground level and was called the piano nobile ("noble floor").
The attic or loft is a storey just below the roof of the building; its ceiling is often pitched and/or at a different height from 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.
Split-level homes have floors that are offset from each other by less than the height of a full storey. A mezzanine, in particular, is typically a floor halfway between two floors.
Numbering
Floor numbering is the numbering scheme used for a building's floors. There are two major schemes in use across the world. In the first system, used in such countries as the United States, Canada, China, Finland, Japan, Norway, Russia, and other ex-Soviet states, the number of floors is counted literally; that is, when one enters a building through the ground-level front door, one walks quite literally on the first floor; the storey above it therefore counts as the second floor. In the other system, used in the majority of European countries, floor at ground level is called the "ground floor", if numbered having 0 as number; the next floor up is assigned the number 1 and is named the first floor (first elevation), the first basement level gets −1, and so on. In both systems, the numbering of higher floors continues sequentially as one goes up, as shown in the following table:
Consecutive number floor designations + Common floor designationsDoes not account for superstitions like triskaidekaphobia or tetraphobia.Height relative to ground (storeys)Common in EuropeCommon in North AmericaTop floorPenthouse (PH), Roof (R/RF), nth floor3 levels above ground storey3rd floor (3/3F)4th floor (4/4F)2 levels above ground storey2nd floor (2/2F)3rd floor (3/3F)1 level above ground storey1st floor (1/1F)2nd floor (2/2F)Partially above ground storeyUpper ground (UG), Upper level (UL), Mezzanine (M), etc.Ground storeyGround floor (G/GF), Lobby (L), Street (S)Elevators may designate the ground floor with a ☆ (like ☆0, ☆1, ☆L, ☆G, etc., most commonly found in North America) or a green ring (most commonly found in Europe).Ground floor or 0 (0/0F)1st floor (1/1F)Partially below ground storeyLower ground (LG), Lower level (LL), Concourse (C), Parking (P), Semi-basement, etc.1 level below ground storey1st basement (−1/−1F/B1)2 levels below ground storey2nd basement, Sub-basement (−2/−2F/B2)3 levels below ground storey3rd basement, Sub-sub-basement (−3/−3F/B3)
Each scheme has further variations depending on how one refers to the ground floor and the subterranean levels. The existence of two incompatible conventions is a common source of confusion in international communication.
However, in all English-speaking countries, the storeys in a building are counted in the same way: a "seven-storey building" is unambiguous, although the top floor would be called "6th floor" in Britain and "7th floor" in America. This contrasts, for example, with French usage, where a 7-storey building is called une maison à 6 (six) étages. Mezzanines may or may not be counted as storeys.
European scheme
Floor at ground level This convention can be traced back to Medieval European usage. In countries that use this system, the floor at ground level is usually referred to by a special name, usually translating as "ground floor" or equivalent. For example, ("ground floor") in Germany (sometimes however, , adopted from French), piano terra or () in Italy, begane grond () in the Netherlands, planta baja (Castilian) or planta baixa (Catalan) in Spain (both meaning "bottom floor"), beheko solairua in Basque, andar térreo ("ground floor") in Brazil, rés-do-chão ("adjacent to the ground") in Portugal, ("ground level") in Hungary (although in Budapest the ("half floor", i.e. mezzanine) is an extra level between the ground and first floors, apparently a circumevention of construction regulations of the 19th and early 20th centuries), (from French street level,:fr:Étage (architecture) where rez is the old French of ras ("scraped"), ("street").rez) in France, parter in Poland and Romania, ("by the ground") in Slovakia, and ("close to the ground") in Slovenia. In some countries that use this scheme, the higher floors may be explicitly qualified as being above the ground level, such as in Slovenian prvo nadstropje (literally "first floor above ceiling (of the ground storey)").
First elevation, Europe, Latin America
In many countries in Europe, the second storey is called the "first floor", for being the first elevation. Besides Europe, this scheme is mostly used in some large Latin American countries (including Mexico, Argentina, Brazil, Paraguay, and Uruguay), and British Commonwealth nations (except Singapore and Canada).
First elevation, Spain In Spain, the level above ground level (the mezzanine) is sometimes called ( in Catalan, etc., which literally means "interfloor"), and elevators may skip it. When the next level is different from the others, usually with higher ceiling and better decorations, then it is called principal (main floor). This is because before elevators the apartments in the floor that required less stairs to reach was the most expensive and usually also the most luxurious one. In those cases the "first floor" can therefore be two or three levels above ground level.
First elevation, Italy In Italy, in the ancient palaces the first floor is called piano nobile ("noble floor"), since the noble owners of the palace lived there.
First elevation, France In France, there are two distinct names for storeys at ground level, depending on whether it faces the street (called ,) or a garden (called ). Buildings which have two "ground floors" at different levels (on two opposite faces, usually) might have both.
First elevation, Croatia
The same differentiation is used as well in some buildings in Croatia. The lower level is called (abbr. RA), and the upper prizemlje (PR). If there is only one ground floor, it is called . The latter usage is standard for smaller buildings, such as single-family homes.
North American schemes In the United States, the first floor and ground floor are usually equivalent, being at ground level, and may also be called the "lobby" or "main floor" to indicate the entrance to the building. The storey just above it is the second floor, and so on. The English-speaking parts of Canada generally follow the American convention, although Canada has kept the Commonwealth spelling "storey". In Quebec, the European scheme was formerly used (as in France), but by now it has been mostly replaced by the US system, so that rez-de-chaussée and premier étage ("first stage") are now generally equivalent in Quebec. Mexico, on the other hand, uses the European system.
The North American scheme is used in Finland, Norway, and Iceland. The Icelandic term ("ground floor") refers to the floor at ground level.
Latin America
European scheme: In many Latin American countries (including Argentina, Mexico, Paraguay, Uruguay and Venezuela) the ground floor is called planta baja and the next floor is primer piso. In Brazil the ground floor is called térreo and the next floor is primeiro andar.
In other countries, including Chile, Colombia, Ecuador and Peru, the ground floor is called primer piso (first floor). If planta baja is ever used it means the ground-level floor (although primer piso is used mainly for indoor areas, while planta baja is also used for areas outside the building).
East and Southeast Asian schemes Most parts of East and Southeast Asia—including China (except for Hong Kong), Japan, Korea, and Singapore—follow the American system. Indonesia uses both the American and European systems. In the grammar of the respective languages, the numbers precede the word "floor", and are cardinals rather than ordinals, so they would translate literally as "1 floor (1F), 2 floor (2F)" (etc.), rather than "1st floor, 2nd floor", or "floor 1, floor 2".
Singapore In Singapore, the British system of numbering originally prevailed. This was replaced in March 1983 with the North American scheme to create a simplified and consistent standard of numbering storeys. To emphasise the difference from the original scheme, reference is frequently made to storeys rather than floors, where the third (3rd) floor becomes either the fourth (4th) storey/level (storey/level 4). Many buildings continue to label storeys or levels rather than floors. However, in the absence of clear official distinction between the terms, the meaning of "floors" and "levels" have become interchangeable with "storey"; this is reflected in newer buildings. Some buildings in Singapore do use SL (Street Level) for ground level, while others such as Nex and West Coast Plaza uses the European scheme, albeit using "Basement 1" for ground level storey.
Vietnam