In 1776, when his interior decorative work was Nostell was nearing completion, Adam proposed making considerable architectural alterations to the house. The 5th Baronet required space for his growing family, but the extent of Adam’s designs was far more significant than this reason could dictate. Adam proposed the rearrangement of the central block, and the addition of four new wings with new vestibules and light wells between the two southern and two northern wings.

These drawings show Adam’s designs for alterations to the house. We know from Adam’s account for the corresponding presentation drawings, that he also produced a plan for the attic storey, and a section through the house, although neither of these survives. Adam’s proposal to build new wings required the demolition of Paine’s kitchen and brewhouse pavilions on the south-west and south-west corners of the central block. In the event, only Paine’s brewhouse pavilion was demolished in preparation for Adam’s replacement, but this was not executed, and there remains an empty space on the south-east corner of the house.

In 1776, work on the north-east family wing began immediately. This wing and the adjacent vestibule on the north front, were the only elements of Adam’s new scheme to be completed. The vestibule on the north front has been amalgamated into the green dressing room (later the billiard room), as the north-east wing was not built, and therefore the vestibule served no purpose. Work was halted on Adam’s architectural alterations to Nostell in 1785 on the 5th Baronet’s death, and his widow, Sabine’s realisation that the family was in financial difficulty.

There is a set of five 1776 finished drawings – duplicates of these designs – within the private collection of Lord St Oswald. There are also 15 working drawings for the construction of the family wing in an Adam office hand, and dated or datable to 1776-78 within the National Trust drawings collection at Nostell.