As in the ground floor plan on drawing 16, the library has three south-facing windows and a chimney-piece on the east wall. Bookcases line the other three walls, with the west bookcase containing several deep shelves for storing folios.

Pencil inscriptions on drawing 22 specify the colour of the east wall: white over the chimney-piece, a band of green above, and a white cornice. A note on drawing 23 specifies a frieze like that made for Mr Windham, most likely referring to the music room Soane designed for William Windham at Earsham, Norfolk, 1784-85 (q.v.). Another moulding in the library (the sheet is trimmed) is to be a replica of a design for Robert Fellowes at Shotesham Park, Norfolk, 1785-90 (q.v.). Soane often reused his designs, especially for joinery and plasterwork.

Drawings 22 and 23 vary slightly in their bookcase designs.