 The E-shaped plan, of which the central range had been doubled in depth in the seventeenth century, was retained.Campbell presented a plan for the south elevation, which was modified in the execution, but he was principally involved in remaking the interiors, where his presence is commemorated in the stucco portrait bust of him in the soffit of the bay window at the south end of the Gallery, which is the sole surviving contemporary image of the Scottish architect; the plasterwork is associated with the ""three Germans"" alluded to in the correspondence from Lord Wilmington's gardener William Stuart, one of whom is thought to have been the Anglo-Danish stuccator Charles Stanley.The London plasterer John Hughes supervised the plasterwork.