Drawing 40 has been torn in half (in Soane's day) to form a folder and lacks the plan mentioned in the inscription. The drawing shows a semicircular fanlight approximately 4 feet high and 10 feet wide. A similar drawing in the archives (j/14/1), located in a measuring notebook for painter's work by William Watson and dated April 1828, shows a similar drawing of a fanlight, specifying the 'yellow glass' shown in drawing 40 and labelled as for the Entrance Wall.

A drawing at the Victoria and Albert Museum shows an interior view of the stairwell looking towards the entrance hall. In the drawing, a fanlight is over a door leading into the entrance hall and there appears to be another fanlight over the front door (Victoria and Albert catalogue 3307.78, see P. du Prey for illustration). Although Soane's designs included a porch in front of the entrance, the form of the projecting porch allowed for an external window directly above the front door (see drawing 9).