Piano nobile (Italian for "noble floor" or "noble level", also sometimes referred to by the corresponding French term, bel étage 'beautiful storey') is the architectural term for the principal floor of a palazzo. This floor contains the main reception and bedrooms of the house.
The German term is Beletage (from the French). Both date to the 17th century.
In architecture, a corps de logis (French pronunciation: [kɔʁ də lɔʒi]) is the principal or main block, or central building of a mansion, country or manor house, castle, or palace. It contains the rooms of principal business, the state apartments and the ceremonial or formal entry.
The grandest and finest rooms within the corps de logis are often found not at grade level, but on the first or even the second floor above. This floor is often referred to as the Italian piano nobile, the French bel étage, or the German beletage.
A state room or stateroom in a large European mansion is usually one of a suite of very grand rooms which were designed for use when entertaining royalty. The term was most widely used in the 17th and 18th centuries. They were the most lavishly decorated in the house and contained the finest works of art. State rooms were usually only found in the houses of the upper echelons of the aristocracy, those who were likely to entertain a head of state. They were generally to accommodate and entertain distinguished guests, especially a monarch and/or a royal consort, or other high-ranking aristocrats and state officials, hence the name. In their original form a set of state rooms made up a state apartment, which always included a bedroom.
23 Wall Street (also known as the J.P. Morgan Building) is a four-story office building in the Financial District of Manhattan in New York City, United States. Located at the southeast corner of Wall Street and Broad Street, it was designed by Trowbridge & Livingston in the neoclassical style and constructed from 1913 to 1914. It was originally the headquarters of J.P. Morgan & Co. Since the late 2000s, the building has remained unoccupied for long periods, although it has occasionally been used for events.
The building has a facade of ashlar masonry and pink Tennessee marble. The first floor consists of a piano nobile over a low basement; above are the second story, the main cornice, and two more stories. After its completion, the building became known as the headquarters of J.P. Morgan & Co.—the "House of Morgan"—although its exterior was never signed with the Morgan name. The banking room, which took up nearly the entire ground floor, included offices and was used for banking transactions. This space was designed with a domed, coffered ceiling and, later, a large crystal chandelier. Mechanical systems and vaults were in the basement, and executive offices were placed on the upper floors.
An imperial staircase (sometimes erroneously known as a "double staircase") is the name given to a staircase with divided flights. Usually the first flight rises to a half-landing and then divides into two symmetrical flights both rising with an equal number of steps and turns to the next floor. The feature is reputed to have first been used at El Escorial. One of the grandest examples, the Escalier des Ambassadeurs at the Palace of Versailles, was built by 1680 but demolished in 1752 as the palace was rearranged. The Jordan Staircase of the Winter Palace is a notable example, while other such staircases can be found at Buckingham Palace, Windsor Castle, Palazzo Reale di Caserta, Palacio Real de Madrid and Mentmore Towers.
The advantages of an imperial staircase became apparent during the 18th century, when Matthew Brettingham revolutionised the design of the piano nobile of the London town house. Guests would proceed through a series of reception rooms arranged as a circuit. At large gatherings the two branches could ease the flow of guests arriving and departing, or moving between a ballroom and a supper room on the floor below. An imperial staircase is often used today for similar reasons where two streams of people are moving in opposite directions in buildings as diverse as an opera house to a railway station. This use explains why the first single flight is often wider than the following two divided flights, although narrowing flights are also an architectural trick to lengthen perspective in order to increase the impression of size.