4, Grosvenor Square W1

No. 4 Grosvenor Square is a terraced town house built between 1865 and 1868 by the builder C.J. Freake, with the facade designed by Thomas Cundy III. The interior was largely remodeled from 1931 to 1934 by Lord Gerald Wellesley for the Italian Embassy. The building is constructed of white Suffolk brick and Portland stone, topped with a slate roof, and showcases an Italianate style typical of Cundy.

The house has four storeys, a basement, and a dormered mansard roof, featuring a five-window-wide facade. The ground floor is banded stone with a central porch supported by coupled Tuscan columns. The upper floors have rusticated quoining, with first-floor windows displaying alternating pediments on engaged Corinthian columns. The central window is more elaborate, featuring tripled columns and a crest over a segmental pediment, all with balustraded balconies. The central three balconies are linked and extend over the porch. The second-floor windows have eared architraves and cornices, while the third floor has a simplified version of this design. There is a sill course at the third floor with carved enrichment below the sills. The building is topped with a rich entablature featuring a modillion cornice and a balustraded parapet, which is broken by a central panel surmounted by a cartouche. The area in front of the building has a stone balustraded parapet.

Inside, the house retains the drawing room ceiling and possibly a top-lit marble grand staircase from the 1860s, although the balustrade is from the 1960s, along with some marble chimney pieces. The overall interior style is a restrained Italianate neo-classical design by Gerald Wellesley. This house is one of only four in Grosvenor Square that survived the mid-20th century rebuilding.