The plans shows that the house has a symmetrical seven-bay front to the north (entrance) and the south (garden), each front having a central door. Some other country houses of this period have a double-pile plan consisting of a rectangular block, two ranges deep, divided by a cross-corridor, with a spine wall carrying the chimneys; Coleshill House in Berkshire was one example. The asymmetrical layout of the east-west interior walls at Fairford and the 'Vacuum' in the the west side are puzzling.

Kip's engraved aerial view of c. 1710 shows a two-storey house with a dormer-windowed attic; the offices are to the west of the house. Recent research by Mr C. Hobson shows that the offices as built were 'similar to, but less extensive, than the ones shown in the plan' (email 30.9.13). Soane's alterations to the reception rooms were small ones: chimney-pieces, cornices and bookcases as well as a partition in the hall to make a dressing room and vestibule.

The incomplete plan and elevation in Soane's hand on the verso of drawing 1 seems to be a design for domestic offices within a single block. It is unlikely that this was intended to replace the irregularly laid-out existing offices at Fairford since there is no mention of such work in Soane's office ledgers. This preliminary design may not have been taken any further, or it is for an unidentified scheme.