The walled terraces are thought to have been added in the mid-seventeenth century. Moss states that these walls were embellished by Adam during the first phase of his works in 1777-82 (Moss, pp. 70-71). The presence of the circular drum tower of the brewhouse suggests that these designs must have been made in c.1779, after the brewhouse replaced the laundry tower. Tait suggests that these drawings were unfinished perspectives, possibly with the intention of engraving them in the future (Tait, 1996, pp. 17, 30).