(b. 1734, Foligno, d. 1808, Foligno)
Italian architect. He trained as an architect in his birth town and was a pupil of Luigi Vanvitelli; he worked with him in Rome and Naples. In 1769 he went to Milan with Vanvitelli and became one of Lombardy's most important architects of the time. He was appointed Imperial Architect of the Realm in 1779.
His most famous works in Milan include: Palazzo Ducale (the design of this building was inspired by Vanvitelli) and Palazzo Greppi (the architect's style is more personal and better defined by the clarity and essential nature of the design). Between 1776 and 1780 he designed and built the Villa Reala (Royal Villa) of Monza which can be considered one of his masterpieces. The building he is most famous for, however, is the Teatro alla Scala of Milan (opera house), with its sober and linear façade.
Some of the other buildings he designed in Milan are: Palazzo Belgioioso, Palazzo Casnedi, Palazzo Morigia, Palazzo Cusani, Palazzo del Monte of Pietà, façade of Palazzo dell'Arcivescovado, Teatro della Cannobbiana.
Piermarini was appointed professor in the Academy of Fine Arts of Brera, better known as Brera Academy, Milan, when it was formally founded in 1776.
When he stopped receiving official commissions in Milan, Piermarini retired to his birth town and died there in 1808.