42, Berkeley Square W1

Terraced house, circa 1741–45, possibly by carpenters Edward Cock and Francis Hillyard, the principal developers of Berkeley Square; altered and extended in the late 18th and early 19th centuries; altered circa 1985.

This is an end-of-terrace corner site with a deep rectangular plan. The entrance is in the north return elevation to Hill Street, with a central entrance hall and stair to the rear. Some principal rooms remain on the ground and first floors, but the plan has otherwise been altered and subdivided.

The exterior is stuccoed brick with a slated modern mansard roof and dormers. The building rises four storeys above basement with a modern mansard attic. The ground floor has banded rustication that continues along the elevation of the rear service building and a linking wall. The first floor features French windows; the remainder are sashes, mostly modern replacements. A moulded cornice and parapet run across the front. The east elevation to Berkeley Square has three windows; those above ground floor are fitted with moulded architraves. A bracketed stone balcony with wrought-iron balustrade adorns the first floor, with window guards to the second floor in the same geometric pattern. A shallow pilaster occurs to the left-hand side and at the angle.

The return elevation has a moulded string course above ground floor and a plain one above the first. This elevation is blind up to an entrance bay, which is full-height and canted with three windows. The neo-classical doorcase features sunk-panelled jambs and lion masks to the corners, a patera to the frieze, and a cornice with guttae. The timber panelled door has a patterned fanlight above. Window guards appear on the first-floor windows, with one window to the right of the entrance bay. The end section of this elevation, beyond the shallow pilaster, appears to be an early 19th-century extension. It has a full-height canted bay to the rear with tall casements to the first floor and window guards similar to other elevations. Cast-iron area railings enclose the basement.

The interior retains little that can be confidently dated to the 1740s. A ground-floor room may retain elements of a panelled scheme with an enriched doorcase and modillion cornice, but the eclectic detail of this room—such as the 17th-century-style plaster ceiling—suggests it may date from the late 19th or early 20th century. An elegant late 18th-century open-well stair on a trapezoid plan features a wrought-iron balustrade and unusual reeded mahogany. An oval lantern above has an enriched surround. The first-floor stair landing has doors with architraves and a niche cupboard with moulded surround in late 18th-century style. A late 18th-century marble neo-classical chimneypiece survives, but much of the décor throughout, including cornices, door architraves and dados, dates to circa 1985 and is not of special interest.

A rear service building of one storey and basement, probably dating from the late 18th century, features tripartite sash windows but has been altered with a circa 1985 mansard and is principally of group value.

The history of the square begins in 1696 when the third Lord Berkeley sold his house, Berkeley House in Piccadilly, to the first Duke of Devonshire with a covenant to protect the northward view from the house, which became known as Devonshire House. The fourth Lord Berkeley, honouring the covenant, developed houses along the east side from circa 1738, first named Berkeley Row. The fifth Lord granted leases for the west side in 1741–45, described as being part of a "new intended square called Berkeley Square". Rocque's map of 1746 confirms the name Berkeley Square. The principal developers were carpenters Edward Cock and Francis Hillyard. The gardens belonging to Devonshire House on the south side subsequently became the gardens of Robert Adam's Shelburne, later Lansdowne House, built 1762–68. The north side was gradually built with terraced houses by the Grosvenor Estate. The gardens of Lansdowne House to the south were developed in the 1930s, forming the south return of the square.