"Flat" vs "apartment"

Both words refer to a self-contained residential unit, i.e. one with its own front door, kitchen, toilet (room) and bathroom. In some parts of the world, the word apartment refers to a purpose-built unit in a building, whereas the word flat means a converted unit in an older building, usually a big house. In other places the terms are interchangeable.

The term apartment is favored in North America (although in some cities flat is used for a unit which is part of a house containing two or three units, typically one to a floor). In the UK, the term apartment is more usual in professional real estate and architectural circles where otherwise the term flat is used commonly, but not exclusively, for an apartment on a single level (hence a 'flat' apartment).

An apartment is in a building or converted house in which no space or single unit occupies an entire floor on its own. An apartment is like a subdivision of something bigger.

Apartments are able be defined by their readiness to be rented to the greater public or holiday makers.

In some countries the word "unit" is a more general term referring to both apartments and rental business suites. The word 'unit' is generally used only in the context of a specific building; e.g., "This building has three units" or "I'm going to rent a unit in this building", but not "I'm going to rent a unit somewhere".

Some buildings can be characterized as 'mixed use buildings', meaning part of the building is for commercial, business, or office use, usually on the first floor or first couple of floors, and one or more apartments are found in the rest of the building, usually on the upper floors.

By housing tenure

Condominium, public housing, owner-occupancy, etc.

Tenement law refers to the feudal basis of permanent property such as land or rents. It may be found combined as in "Messuage or Tenement" to encompass all the land, buildings and other assets of a property.

In the United States, some apartment-dwellers own their units, either as co-ops, in which the residents own shares of a corporation that owns the building or development; or in condominiums, whose residents own their apartments and share ownership of the public spaces. Most apartments are in buildings designed for the purpose, but large older houses are sometimes divided into apartments. The word apartment denotes a residential unit or section in a building. In some locations, particularly the United States, the word connotes a rental unit owned by the building owner, and is not typically used for a condominium.

In the England and Wales, some flat owners own shares in the company that owns the freehold of the building as well as holding the flat under a lease. This arrangement is commonly known as a "share of freehold" flat. The freehold company has the right to collect annual ground rents from each of the flat owners in the building. The freeholder can also develop or sell the building, subject to the usual planning and restrictions that might apply. This situation does not happen in Scotland, where long leasehold of residential property was formerly unusual, and is now impossible.

By size of the unit

Bachelor apartment, one-bedroom, etc.; see below.

By size of the building

Apartment buildings are multi-story buildings where three or more residences are contained within one structure. Such a building may be called an apartment building, apartment complex, flat complex, block of flats, tower block, high-rise or, occasionally, mansion block (in British English), especially if it consists of many apartments for rent. A high-rise apartment building is commonly referred to as a residential tower, apartment tower, or block of flats in Australia.

A high-rise building is defined by its height differently in various jurisdictions. It may be only residential, in which case it might also be called a tower block, or it might include other functions such as hotel, offices, or shops. There is no clear difference between a tower block and a skyscraper, although a building with fifty or more stories is generally considered a skyscraper. High-rise buildings became possible with the invention of the elevator (lift) and cheaper, more abundant building materials. Their structural system usually is made of reinforced concrete and steel.

A low-rise building and mid-rise buildings have fewer storeys, but the limits are not always clear. Emporis defines a low-rise as "an enclosed structure below 35 metres which is divided into regular floor levels." The city of Toronto defines a mid-rise as a building between 4 and 12 stories.

By country

In American English, the distinction between rental apartments and condominiums is that while rental buildings are owned by a single entity and rented out to many, condominiums are owned individually, while their owners still pay a monthly or yearly fee for building upkeep. Condominiums are often leased by their owner as rental apartments. A third alternative, the cooperative apartment building (or "co-op"), acts as a corporation with all of the tenants as shareholders of the building. Tenants in cooperative buildings do not own their apartment, but instead own a proportional number of shares of the entire cooperative. As in condominiums, cooperators pay a monthly fee for building upkeep. Co-ops are common in cities such as New York, and have gained some popularity in other larger urban areas in the U.S.

In British English the usual word is "flat", but apartment is used by property developers to denote expensive 'flats' in exclusive and expensive residential areas in, for example, parts of London such as Belgravia and Hampstead. In Scotland, it is called a block of flats or, if it is a traditional sandstone building, a tenement, a term which has a negative connotation elsewhere.

Australian English and New Zealand English traditionally used the term flat (although it also applies to any rental property), and more recently also use the terms unit or apartment. In Australia, a 'unit' refers to flats, apartments or even semi-detached houses. In Australia, the terms "unit", "flat" and "apartment" are largely used interchangeably. Newer high-rise buildings are more often marketed as "apartments", as the term "flats" carries colloquial connotations. The term condominium or condo is rarely used in Australia despite attempts by developers to market it.

In South African English, an apartment is usually a single level rental area that is a part of a larger building and can be entered from inside the building through a separate door leading off either a wind tunnel or entrance hall/lobby that is shared with other occupants of the building.

In Malaysian English, flat often denotes a housing block of two rooms with walk-up, no lift, without facilities, typically five storeys tall, and with outdoor parking space, while apartment is more generic and may also include luxury condominiums.

In Japanese English loanwords (Wasei-eigo), the term apartment (apaato) is used for lower-income housing and mansion (manshono) is used for high-end apartments; but both terms refer to what English-speakers regard as an apartment (or condominium) and not the level of luxury of a mansion in English parlance. See Housing in Japan. Danchi is the Japanese word for a large cluster of apartment buildings of a particular style and design, typically built as public housing by government authorities.

Studio apartment

The smallest self-contained apartments are referred to as studio, efficiency or bachelor apartments in the US, or studio flat in the UK. These units usually consist of a large single main room which acts as the living room, dining room and bedroom combined and usually also includes kitchen facilities, with a separate bathroom. In Korea, the term "one room" (wonroom) refers to a studio apartment.

A bedsit is a UK variant on single room accommodation: a bed-sitting room, probably without cooking facilities, with a shared bathroom. A bedsit is not self-contained and so is not an apartment or flat as this article uses the terms; it forms part of what the UK government calls a House in multiple occupation

Garden apartment (US)

Merriam-Webster defines a garden apartment in American English as "a multiple-unit low-rise dwelling having considerable lawn or garden space" The apartment buildings are often arranged around courtyards that are open at one end. Such a garden apartment shares some characteristics of a townhouse: each apartment has its own building entrance, or shares that entrance via a staircase and lobby that adjoins other units immediately above and/or below it. Unlike a townhouse, each apartment occupies only one level. Such garden apartment buildings are almost never more than three stories high, since they typically lack elevators. However, the first "garden apartment" buildings in New York, USA, built in the early 1900s, were constructed five stories high. Some garden apartment buildings place a one-car garage under each apartment. The interior grounds are often landscaped.

Garden flat (UK)

The Oxford English Dictionary defines the use of "garden flat" in British English as "a basement or ground-floor flat with a view of and access to a garden or lawn", although its citations acknowledge that the reference to a garden may be illusory. "Garden flat" can serve simply as a euphemism for a basement. The large Georgian or Vict