Although these two survey drawings for Black Rod's house are undated, preceding drawings in the sketchbook are dated '1828' and later drawings are for Sir Francis Chantrey's house, at which Soane built a new ante-room in 1830-31. Soane had previously made designs for alterations and additions to Black Rod's House in May 1826 that were not executed (SM 51/3/7-8). Sir Thomas Tyrwhitt (1762-1833) served as Black Rod between 1812 and 1832.