The proposed interior scheme was extremely opulent, making use of scagliola for the shafts of the screen columns, and dense ornamentation to the colourful walls and ceiling (Adam volume 12/120). Such opulence would have been expensive, and it was perhaps owing to this projected cost that the scheme was not executed.

These sections show that Adam was making use of his characteristic linear decoration of the 1770s, as well as multiple screened apses which he used throughout his career. Indeed, the scheme is datable by its style, as Stillman explains: 'The lithe arches of the back wall with their attenuated supports, the arabesque and bell flower stops, the complex alternating frieze, the capitals inspired by Spalatro, the Neo-classical subject panels, and the small-scale decorative panels of the apse and vault are all in keeping with Adam’s most exciting decorative projects of the same years (e.g. Derby House or Northumberland House).'