Piano nobile

An early-15th-century piano nobile at the Palazzo dei Diamanti, Ferrara. Its larger windows indicate its superior status compared with the rooms on the floor below.
The Beletage of Dresden's Villa Martha, built in the 1870s
At the 18th-century Kedleston Hall in Derbyshire, the piano nobile is placed above a rusticated ground floor, and reached by an external staircase. The uppermost windows indicate that the upper floor is of far lower status.

Piano nobile (Italian for "noble floor" or "noble level", also sometimes referred to by the corresponding French term, bel étage) 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 (meaning "beautiful storey", from the French bel étage). Both date to the 17th century.