Penthouse apartment

A penthouse apartment or a penthouse is an apartment on the highest floor of an apartment building or a hotel. It can also be located on the bottom floor with a built in garage. Penthouses are typically differentiated from other apartments by luxury features. The term penthouse originally referred to, and sometimes still does refer to, a separate smaller "house" that was constructed on the roof of an apartment building.

The idea of a penthouse apartment was born in the 1920s, called “The Roaring Twenties”, when economic growth brought a construction boom to New York City, the heart of the American economy. The high demand for living in urban areas and the wealth of Americans led to luxury apartments on the top floor or floors of buildings.

One of the earliest penthouse apartments in the city was publisher Conde Nast’s duplex penthouse at 1040 Park Avenue. The original 1923 plan for the building provided three units on each floor with additional maids’ rooms on the roof, but in 1924, the building’s upper spaces were constructed to provide the grand duplex for Nast. Connected by a staircase to the rooftop entertaining salons, the corner unit at the top floor was redesigned to be private family quarters. The whole unit was decorated in the French manner by Elsie de Wolfe. Completed in 1925, Conde Nast’s duplex penthouse was used for many lavish parties, which were made famous as much by guest lists as by the entertainment.

In architecture, the term penthouse is used to refer to a structure on the roof of a building that is set back from the outer walls. These structures do not occupy the entire roof deck. High-rise buildings often have penthouse structures called mechanical penthouses that enclose mechanisms such as elevator equipment.

While European designers and architects long recognized the potential in creating living spaces that make use of rooftops and such setbacks, in US cities, exploitation of these spaces began in earnest in the 1920s. It was a matter of news when the development of a rooftop apartment at the Plaza Hotel overlooking Central Park was announced in 1923, and this was followed by rapid development of luxury penthouse apartments in the following years.

...
Wikipedia