The great drawing room, or third drawing room, was located on the first storey of the house, at the near end of the rear wing, above the great dining room, behind the staircase, and adjacent to the Etruscan dressing room. A plan of the house can be found in the second volume of The works in architecture of Robert and James Adam (part 1, plate 1).

The groin-vaulted ceiling of the great drawing room is included in the second volume of the Works (part 1, plate 5), and is illustrated in accordance with Adam's design (Adam volume 12/144). Adam's preface to this plate reads:

Inside View of the Third and Great Withdrawing-room. The ornaments of the cieling and entablature are chiefly of stucco gilt, with a mixture of paintings. The grounds are coloured with various tints...

Here it is suggested that the ceiling - in both Adam's drawing and the Works - is shown as executed. However, the ceiling was lost when the house was demolished in 1862.

According to Harris, Adam's inspiration for this design came from Giovanni da Udine's painted ceiling in the Vatican loggia, and the Villa Madama, as well as Adam's earlier ceilings such as those for the drawing rooms at Lansdowne House (1967), and Northumberland House (1770).

The Adam office drawing made for the production of plate 5 in the Works was sold from the collection of Edward Croft Murray at Christie's on 9 July 1996 for £49,900.