Building 17 at Cromford Mill

Building 17 at Cromford Mill is a late 18th century cotton spinning mill that was altered and converted for office use and a visitor exhibition in 2014. It is constructed of millstone grit and features a hipped slate roof and timber sash windows.

The building has a long, rectangular plan oriented east to west, with an apsidal eastern end. The north elevation, which faces the courtyard, has 12 bays with timber sash windows arranged in eight over eight panes, secondary glazing, four doorways, and signs of removed external additions. The apsidal east end includes one bay of timber sash windows with eight over eight panes and a doorway, and it is connected on two floors to Building 16 by a brick arched bridge. The west end connects to the first mill (Building 18) via a brick bridge that is lit by a small window, and a Gibbs surround doorway provides access into Building 18.

The south elevation, facing the road, also has 12 bays with timber sash windows of eight over eight panes and secondary glazing, but lacks windows at ground floor level, featuring two infilled windows and a domestic-scale door instead.

Inside, the ground floor is partly open plan and serves as exhibition space for the Derwent Valley Mills World Heritage Site Visitor Centre. Plasterboard walls have been installed to seal in contamination from the building's previous use as a colour works. Recent alterations include a modern central staircase and lift, as well as mainly glazed partitions that subdivide floors one to four into individual offices. Corridors have been created at the front of the building on each floor, featuring modern doors and partitioning. The top floor retains more of its open plan layout, with original roof trusses partially visible.