A complicated day's entry, as Soane sketches out three different aspects of the build, working on measurements for the heights of the rooms.
The first sketch shows his new loggia with the large arched opening being that of the porch and adjacent smaller arched opening being the west opening to the balcony with the masonry blocks of Portland-stone shown around the top of the arch; above is the supporting timber, or 'wall plate' running horizontally from left to right and a series of smaller joists above it which hold up the floor of the South Drawing Room. The reference to No.12 indicates that this sketch is a comparison with the height of the existing house, and Soane is trying to foresee some of the complaints that lay in waiting for him. HH are the initials of Henry Harrison, a fellow architect and surveyor.
The second sketch is an elevation of the three arched inner openings of the loggia and the horizontal beam above (supporting the first floor) with measurements again marked. The two side arches are shown to contain books (ie bookcases) to a height of 8 feet 7 inches, whilst the central arch provides access for guests to the loggia. As built in 1812, this was an open balcony, although Soane would later enclose it to its present appearance. The Eating Room is the Dining Room. The overall height of the stonework for the loggia is noted as 8 feet 7 inches to the sprigging of the loggia arches, with a further 5 feet 5 inches to the top of the plate, giving a total of 14 feet. Again the measurements were taken by H Harrison.
The third and final sketch shows a section and plan through the No. 13 staircase hall looking south showing the large opening between staircase and front entrance hall (on the left) and the adjacent niche, with the steps of the main staircase shown and measurements marked. Above the large arch (marked faintly in pencil) is the door to the South Drawing Room from the first floor landing. Again the heights are noted, showing that the height comes to 8 feet and 7 inches - this is to verify that the heights to the springing of the arches are the same in the staircase as they are at the front of the building - in other words, is the ground floor level and is the height of the arches set out correctly.