75, South Audley Street W1

No. 75 South Audley Street is a former terraced town mansion, originally built between 1736 and 1738 as three separate houses by Edward Shepherd. It was combined into one house known as Bute House between 1774 and 1776 by "Capability" Brown and Henry Holland, with possible alterations by Robert Mylne around 1802. The building was refronted in 1907 by C.J. Corblet and underwent a grand interior refurbishment for the Legation in 1927 by Fern and Billerey.

The exterior features a Portland stone front, with stucco on the return and rear, and a slate roof. The 1907 façade presents a "Palladian" style but retains full-height bows from the late 18th and early 19th centuries at the rear. The building is two storeys high, with a basement and attic storey, and is seven windows wide. The entrance is located in the third bay from the right, framed by engaged Corinthian columns, an entablature, and a pediment. The windows are architraved, with pediments over most on the ground floor, and an elaborated architrave with an open scrolled pediment above the doorway. The ground and first floors are articulated by a giant order of Roman Ionic pilasters that rise from a rusticated basement to the main entablature, which features a modillion cornice. The attic includes enriched pilaster strips aligned with the giant order and a balustraded crowning parapet.

The rear bows feature recessed glazing bar sashes and are complemented by cast iron area railings in a late 18th-century style, topped with urn finials. The interior is finely executed in the French Louis XVI and English 18th-century styles, retaining elements of earlier decorations. Notable features include late 18th-century chimney pieces made of statuary marble, painted "grotesques" from the Bute family's occupation, and painted friezes and ceiling panels. The roundels in the ceiling of the north room of the first-floor suite are reset Tiepolo canvases, with the main ceiling panel titled "Allegory of Venus and Time" now housed in the National Gallery, introduced in 1876.