The Hon. John Grant (d. 1777) was a lawyer, and the eldest son of the Scottish judge Patrick Grant, Lord Elchies. He became a Baron of the Court of Exchequer in Scotland, and owned large sugar plantation in Granada, which afforded him the wealth to acquire and remodel a large London townhouse at 20 Soho Square.

Soho Square was developed with forty-one houses from 1677-91 on Soho Fields, by Richard Frith, a bricklayer, and Cadogan Thomas, a timber merchant. The original house at number 20, on the east side of the square, was a three-storey, five-bay house with a 64-foot façade. Shortly after construction, the neighbouring two-bay house was incorporated, forming a larger single dwelling for Oliver Cromwell's son-in-law, Thomas Belasyse, 1st Earl of Fauconberg, who lived there from at least 1683-1700. This alteration from two houses into one house resulted in uneven fenestration, and the two southern bays were more widely spaced than their five northern counterparts. Following Lady Fauconberg's death in c1712-13 the lease passed through various hands, until it was sold on the death of the 4th Duke of Argyll in 1770 to Baron Grant.

On his acquisition of 20 Soho Square, Grant quickly consulted Robert Adam about refacing the house, and providing new interior decorative schemes. Various potentially expensive structural alterations were not made. These included a scheme for an additional wing containing a gallery and library connecting with a new stable court. Adam's design to reface the principal front (facing Soho Square) was executed, with a rusticated basement surmounted by eight Ionic pilasters articulating the bays across the first and second storeys. Moreover, Adam's designs for remodelling the interior were also executed, and resulted in characteristic variously shaped rooms, and new decorative schemes.

On the principal (first) floor Adam worked on the oval first drawing room, the square second drawing room, the apsidal third drawing room, and a bedroom for Baron Grant, and on the parlour (ground) floor he worked on the eating room, the oval parlour, Baron Grant's dressing room, and possibly the lobby, as well as redecorating the staircase between these two floors. Drawings survive for at least one element of each of these rooms. It is thought that all of Adam's designs for the interior decoration of the house were executed, although this is largely speculative as there was a large-scale programme of redecoration in the nineteenth century. Adam's interiors included painted panels by both Angelica Kauffman and Biagio Rebecca. These were removed by the owner in 1906 to his house at Bushey, Hertfordshire.

The cost of Adam's works at 20 Soho Square required Grant to take a mortgage on the property in 1773, and a few months later he moved out. It stood empty for a decade as the square was becoming a commercial area rather than a domestic one. It was eventually sub-let as John Wright's Hotel and Coffee House, later the Crown Coffee House and Tavern. Next in 1810-57 the house was used as the premises of a musical instrument maker and seller, and then in 1858 it was taken over by Messrs. Crosse and Blackwell (already in ownership of number 21), oilmen and salters. The two neighbouring buildings were altered and enlarged by Crosse and Blackwell to meet their needs, including the addition of a jam and pickle factory at the rear. Finally, in 1924, the eighteenth-century house was demolished to make way for a new high-rise office block for Crosse and Blackwell, built in 1924-26 by Messrs Joseph; the building remains in use as offices.

Literature:
A.T. Bolton, The architecture of Robert and James Adam, 1922, Volume II, Index pp. 50, 72; E. Harris, The furniture of Robert Adam, 1963, Index p. 58; Survey of London, Volume xxxiii, 1966, pp. 42-50, 69-72; B. Weinreb, and C. Hibbert, The London encyclopaedia, 1983, pp. 816-17; D. King, The complete works of Robert & James Adam and unbuilt Adam, 2001, Volume I, pp. 264, 272-75; S. Bradley, and N. Pevsner, The buildings of England: London 6: Westminster, 2003, pp. 426-28

Frances Sands, 2013