The back parlour was at the rear, on the ground storey of the house.

A close variant of the design was executed, with jugs rather than rosettes in the capitals. It survived to be photographed by the LCC in 1936, although the photograph is mislabelled as being for the front drawing room rather than the back parlour.

This design is similar, with the same frieze and capitals, as that designed by Adam in 1769 for the back parlour at 10 Hertford Street (Adam volume 22/266). The Hertford Street design is inscribed in pencil with the words, [Bac]k Parlor River / [cropped]t House River, corresponding with the intended location of this design.