Drawings 56 to 63 are alternative designs for the new wing. Soane's built addition is shown in grey wash while the proposed rooms are in pink wash. In all of the drawings the old house is not included, probably suggesting its complete replacement. The drawings show alternative designs for rooms arranged around the circular tribune.

Drawing 56 is a design for a new wing with, as in drawing 52, a 'hall' (later music hall) on a north-south axis aligned with the tribune and south portico. A drawing room is on the east end of the addition, mirrored the existing library and breakfast room that lie to the west. The south portico projects on four columns and leads to the tribune. Drawing 57 is an elevation that corresponds to drawing 56, with a projecting Ionic portico between six bays, the single-storey top-lit tribune positioned behind the portico and surrounded by the three-storey building.

Drawings 59 to 62 correspond with the plan on drawing 52. The entrance front (drawings 59 and 60) has a round-headed arch framed by a twin Doric order and surmounted by two sculpted couchant lions with a foliate sash draped between them. The portico forms the end of a projecting three-storey wing between seven bays. At the rear elevation (drawings 61 and 62), the thirteen-bay three-storey building surrounds the single-storey tribune on three sides. As in drawing 57, this design allows for the tribune to continue as a top-lit room. Variation is provided on the elevation by projecting bays: in drawing 60 the end bays slightly push forward and in drawing 59 they are set back.

Drawing 63 resembles drawing 58 but with symmetrical east and west wings. Both drawings 58 and 63 show a square vestibule fronted by four columns linking with the entrance halle. In drawing 63, a long portico is attached to the south front. Both drawings include an east-west enfilade extending the length of the house.