A Venetian window (also known as a Serlian or Palladian window or Serlian motif) is a distinctive architectural element that consists of a central arched window flanked by two smaller rectangular windows. This design is often used in classical architecture and has been widely employed in Renaissance, Baroque, and Neoclassical buildings. Although Sebastiano Serlio (1475–1554) did not invent it, the window features largely in the work of the Italian architect Andrea Palladio (1508–1580) and is almost a trademark of his early career. The true Palladian window is an elaborated version. Both the Venetian window or Serlian window and the Palladian window were inspired by Hellenistic and Roman examples which are part of the classical tradition and related to prestige and sacredness. ^[1]

The Venetian window consists of an arched central light, symmetrically flanked by two shorter sidelights. Each sidelight is flanked by two columns or pilasters and topped by a small entablature. The entablatures serve as imposts supporting the semicircular arch that tops the central light. In the library at Venice, Sansovino varied the design by substituting columns for the two inner pilasters. To describe its origin as being either Palladian or Venetian is not accurate; the motif was first used by Donato Bramante^[2] and later mentioned by Serlio in his seven-volume architectural book Tutte l'opere d'architettura et prospetiva expounding the ideals of Vitruvius and Roman architecture, this arched window is flanked by two lower rectangular openings, a motif that first appeared in the triumphal arches of ancient Rome.

Palladio used the motif extensively, most notably in the arcades of the Basilica Palladiana in Vicenza. It is also a feature of his entrance to Villa Forni Cerato. It is perhaps this extensive use of the motif in the Veneto that has given the window its alternative name of the Venetian window; it is also known as a Serlian window. Whatever the name or the origin, this form of window has probably become one of the most enduring features of Palladio's work seen in the later architectural styles evolved from Palladianism.^[3] According to James Lees-Milne, its first appearance in Britain was in the remodeled wings of Burlington House, London, where the immediate source was actually in Inigo Jones's designs for Whitehall Palace rather than drawn from Palladio himself.^[4]

The Palladian window or "Palladio motif" is Palladio's elaboration of this, normally used in a series. It places a larger or giant order in between each window, and doubles the small columns supporting the side lintels, placing the second column behind rather than beside the first. This is introduced in the Basilica Palladiana in Vicenza,^[5] where it is used on both storeys; this feature was less often copied. Here the openings are not strictly windows, as they enclose a loggia. Pilasters might replace columns, as in other contexts. Sir John Summerson suggests that the omission of the doubled columns may be allowed, but "the term "Palladian motif" should be confined" to cases where the larger order is present.^[6]

A variant, in which the motif is enclosed within a relieving blind arch that unifies the motif, is not Palladian, though Burlington seems to have assumed it was so, in using a drawing in his possession showing three such features in a plain wall (see illustration of Claydon House right). Modern scholarship attributes the drawing to Scamozzi. Burlington employed the motif in 1721 for an elevation of Tottenham Park in Savernake Forest for his brother-in-law Lord Bruce (since remodelled). Kent picked it up in his designs for the Houses of Parliament, and it appears in Kent's executed designs for the north front of Holkham Hall.^[7]

The Ipswich window is another variant.^[8]

The Venetian window design originates from the Renaissance period and is strongly associated with the Italian architect Andrea Palladio (1508–1580), who used it extensively in his works. However, its conceptual origins can be traced back to the earlier architect Sebastiano Serlio (1475–1554), who described a similar window form in his treatise Tutte l'opere d'architettura et prospettiva (1537). Because of Serlio’s early documentation, the window is sometimes referred to as a Serlian window.^[9]

Palladio further refined the form and integrated it into his villas and palaces, which led to its popularization across Europe and later in the United States during the 18th and 19th centuries.

A typical Venetian window consists of:

• A large central arched opening that provides a focal point.
• Two smaller rectangular side windows that are usually separated from the central arch by slender columns or pilasters.
• A decorative entablature or cornice that unifies the composition.
• Sometimes a balustrade or balcony beneath the window, especially in grand residences and palaces.

Andrea Palladio extensively incorporated the Venetian window motif into his architectural designs, particularly in his villa and palace facades. One of the most famous examples is the Villa Godi (1542), where Palladio utilized the motif to enhance symmetry and grandeur.^[10]

During the Baroque and Neoclassical periods, the Venetian window became a favored design element in both Europe and North America. In England, architects such as Richard Boyle, 3rd Earl of Burlington (1694–1753) incorporated Palladian windows into their designs, further cementing their association with Palladianism. Notable examples include:

• Chiswick House, London (1729)
• The White House, Washington, D.C. (1792–1800), where Palladian windows are seen in its design.

The motif was widely used in American Colonial and Federal architecture, often appearing in grand homes and public buildings. It was particularly popular in the designs of Thomas Jefferson, who integrated Palladian elements into his works such as:

• Monticello, Virginia (1772)
• The Virginia State Capitol, Richmond (1788)

In modern architecture, the Venetian window remains a popular design element, often appearing in neoclassical and revivalist buildings. Contemporary adaptations may incorporate materials like aluminum and glass, while maintaining the fundamental tripartite composition.^[11]

• 
  A corner of the Basilica Palladiana, Vicenza, with Palladian window openings to the loggia
• 
  Pair of Palladian windows on wings of south front of Burlington House, Westminster, the earliest appearance of the element in Britain
• 
  A Venetian window, with blind sides, designed by Isaac de Caus (d.1648)^[12] circa 1647, south front of Wilton House, Wiltshire, England
• 
  Claydon House (begun 1757), here the Venetian window in the central bay is surrounded by a unifying blind arch

• Venetian door

• Parada López de Corselas, Manuel, La serliana en el Imperio Romano: paradigma de la arquitectura del poder: una lectura de la arquitectura y la iconografía arquitectónica romanas, 2015, L'Erma di Bretschneider ISBN 9788891308863
• Parada López de Corselas, Manuel, La serliana en Europa. Fortuna y funciones de un elemento arquitectónico (siglos VII-XVIII), 2019, Centro de Estudios Europa Hispánica ISBN 9788415245834
• Summerson, John, The Classical Language of Architecture, 1980 edition, Thames and Hudson World of Art series, ISBN 0500201773

• Crank Out & Casement Windows Comparison