Most of the building was rebuilt in after years, and little of the original mill remain. It is known from written sources that it was five storeys high rectangular in plan. It was 17m high, 33.5m long, and 12m wide. The roof was slightly sloped. It was built of brick in Flemish bond, on a series of stone arches that allowed the waters of the River Derwent to flow through. The throwing machines were two storeys high, and fastened on the first floor. The winding machines were placed on the top three floors. All the machines were powered by Sorocolds external undershot water wheel. It was 7m in diameter and 2m in width. Its stem entered the mill through a hole at first floor level. It drove a vertical shaft which was 0.45m square. This drove a line shaft (horizontal shaft or lay shaft) that ran the length of the mill. The "torcitoios" and "filatoios" took their power from this shaft. The vertical shaft was extended to a further vertical shaft that reached the top 3 floors to drive the winding machines. The mill needed to be heated in order to process the silk and this was explained in the 1718 patent. It was reported in 1732 that Lombe used a fire engine (steam engine) to pump hot air round the mill. The stair column was 19.5m high, but its layout is unknown. There is no information on how materials were carried up and down between the floors.