Types of apartments

Penthouse apartment
A penthouse apartment or penthouse is an apartment that is on one of the highest floors of an apartment building. Penthouses are typically differentiated from other apartments by luxury features.
In architecture, the term penthouse is used to refer to a structure on the roof a building that is set back from the outer walls. These structures do not occupy the entire roof deck. High-rise buildings will often have penthouse structures enclosing mechanics such as those in an elevator machine room.

Designers and architects recognized the potential in creating living spaces that make use of setbacks. When used as private outdoor terrace spaces, setbacks can allow for significantly larger and more protected spaces than cantilevered balconies. Due to the desirability of this outdoor space, buildings may be designed with such setbacks on more than one of its uppermost levels, to allow apartments on several levels to feature such terraces. Not all penthouses have such terraces, but they are a desired feature. One such space may be divided among several apartments, or one apartment may occupy an entire floor. A penthouse apartments may also provide occupants with private access to the roof space above the apartment, instead of or in addition to terrace space created by an adjacent setback.
A penthouse apartment may have additional exclusive features not found in the majority of apartments in the building, such as a private entrance or elevator, or higher ceilings. In buildings consisting primarily of single level apartments, a penthouse apartment may be distinguished by having two or more levels.
Penthouse apartments are generally expensive, and are often associated with a luxury lifestyle. Thus, those wishing to market or otherwise inflate the prestige of a particular apartment may use the term. The term penthouse is sometimes applied to apartments that are no different than others in a building, other than being on one of the uppermost floors. The term sub-penthouse is sometimes used to describe apartments near the top of a building, when the term penthouse is reserved for the uppermost floor.

Railroad apartment
A railroad apartment is an apartment with a series of rooms that connect to each other in a straight line just like cars on a train. Often, there is an entrance at only one end, so a resident must walk through each room to get to the next, though sometimes there is a narrow hallway.
The term is common in New York City, San Francisco and nearby areas. Railroad apartments are common in brownstone apartment buildings.
A railroad apartment is similar to a shotgun house

Short stay apartment
A Short Stay Apartment is a furnished apartment that is rented for short periods of time, usually days or weeks. They are quickly becoming a preferred alternative to hotels for various reasons. A short stay apartment is a self-contained apartment space which will include a lounge, a bathroom and a kitchen. The apartment layout can vary from one-room studios to various roomed luxury apartments with many bedrooms.
The ability to temporarily own your own apartment offers plenty of freedom for its guests, for example, cooking and sharing a family meal. Many families travelling will often prefer to live together, eating and sleeping in one single apartment, rather than spread out around several hotel rooms.
A short stay apartment is a valid alternative to hotels for groups of people and families, as well as businessmen. Apartments are often available in good locations within city centers. Private villas also can be rented for short stays which are often located in rural areas or even coastal regions.
Quality
Quality of the apartments can vary. Many people who own a second home rent it out for short stays, some use an agency that specialises in renting out apartments, other choose to rent it out themselves, publishing it on websites. Often, agencies offer a higher standard of apartment, realising that people who rent a short stay apartment want comfort and a good standard of furnishing, they also usually offer greater levels of customer service.
Individual owners who manage their own properties may be cheaper, although the furnishing and decoration may not be as high-standard, and there may be little or no customer service during the stay should something occur.
Extended Stays
Business executives increasingly prefer a short stay apartment to hotel rooms. Apartments offer more privacy and freedom, and can be cost-effective. Short stays of more than one month are often called extended-stays. Many apartments come equipped with desks and internet connections, some even provide small offices, designed for business executives on short contracts etc.

High-rise
A high-rise is a tall building or structure. Normally, the function of the building is added, for example high-rise apartment building or high-rise offices.
High-rise buildings became possible with the invention of the elevator (lift) and cheaper, more abundant building materials. Buildings between 75 feet and 491 feet (23 m to 150 m) high are considered high-rises. Buildings taller than 492 feet (150 m) are classified as skycrapers. The average height of a level is around 13 feet (4 m) high, thus a 79 foot (24 m) tall building would comprise 6 floors.
The materials used for the structural system of high-rise buildings are reinforced concrete and steel. Most American style skyscrapers have a steel frame, while residential tower blocks are usually constructed out of concrete.
Although the exact definition is immaterial, various bodies have tried to define what 'high-rise' means:
The International Conference on Fire Safety in High-Rise Buildings defined a high-rise as "any structure where the height can have a serious impact on evacuation"
The New Shorter Oxford English Dictionary defines a high-rise as "a building having many stories".
Massachusetts General Laws define a high-rise as being higher than 70 feet (21 m).
Most building engineers, inspectors, architects and similar professions define a high-rise as a building that's at least 75 feet (23 m).
High-rise structures pose particular design challenges for structural and geotechnical engineers, particularly if situated in a seismically active region or if the underlying soils have geotechnical risk factors such as high compressibility or bay mud. They also pose serious challenges to firefighters during emergencies in high-rise structures. New and old building design, building systems like the building standpipe system, HVAC systems (Heating, Ventilation and Air conditioning), fire sprinkler system and other things like stairwell and elevator evacuations pose significant problems.

Loft apartment
Loft apartments are apartments that are generally built into former industrial buildings. When industrial developments are developed into condominiums instead of apartments, they may be called loft condominiums. The general term warehouse-to-loft conversions may sometimes be used for development of industrial buildings into apartments and condominiums. "Loft-style" may also refer simply to developments where a street-level business occupies the first floor while apartment "lofts" are placed above the first floor.
These dwellings may advertise "exposed brick" and are the two-story equivalent of studio apartments. Loft apartments generally have one open room having the bedroom in a loft while the kitchen and living room comprise the first floor. This style may be chosen for redevelopment of industrial buildings due to the original high-roofed room design of such buildings. Sometimes, loft apartments are one component of municipal urban renewal initiatives that also include renovation of industrial buildings into art galleries and studio space as well as promotion of a new part of the city as an "arts district."
Originally popular with artists, they are now highly sought-after by other bohemians, and the gentrification of the former manufacturing sectors of large cities is now a familiar pattern. One such sector is Manhattan's Meatpacking District. The adoption of the Adaptive Reuse Ordinance (2001) in the City of Los Angels (primarily the Arts District) is another example of such legislation to encourage the conversion of no longer economically viable industrial and commercial buildings to luxurious residential loft communities. Such is the demand for these spaces among the well-off that real estate developers have taken to creating ready-made "lofts" in urban areas that are gentrifying or that seem primed to do so. While some of these units are created by developers during the extensive and costly renovation of old buildings, a number of them are included in the floor plans of brand new developments. Both types of pre-fab loft offer wealthy buyers or renters the proximity to urban amenities afforded by traditional lofts, but without the perceived safety risks of living in economically depressed industrial areas. Detractors argue that these ready-made units are neither produced nor consumed in the spirit of traditional loft living.

Garage apartment
A garage apartment is an apartment built within the walls of, or on top of, the garage of a house. The garage may be attached or a separate building from the main house, but will have a separate entrance and may or may not have a communicating door to the main house. A garage apartment is one type of "Accessory Dwelling Unit" or ADU, a term used by architects, urban planners and in zoning ordinance to identify apartments smaller than the main dwelling on one lot or parcel of land. Other examples of ADU's include granny flats, English basements, mother-in-law suites, and auxiliary units.
In the U.S., garage apartments are frequently found in older urban areas, either in secondary buildings designed for such purposes (sometimes called 'guest' or 'carriage' houses), or converted into residential units from their original use. ADUs may be regulated by size, occupancy, lot size, core features (such as kitchens or bathrooms), other building codes and parking allotment.
Many jurisdictions in the U.S. prohibit new construction of or occupancy of ADUs except for relatives

Serviced apartment
serviced apartment is a type of furnished, self-contained apartment designed for short-term stays, which provides amenities for daily use.
Serviced apartments can be less expensive than equivalent hotel rooms. Since the beginning of the boom in cheap international travel and the corresponding increase in the level of sophistication of international travellers, interest in serviced apartments has risen at the expense of the use of hotels for short stays.
Since the dot-com crash, company budgets have been squeezed and since when staying in a hotel one is paying for facilities such as restaurants and bars which are often not needed, many companies have switched their accommodation budgets to serviced apartments