James Bruce built a wooden mill on this site in 1878, but this was burned down in 1881. He began rebuilding immediately, and in September 1882 opened the new mill, which was the first in New Zealand to be equipped with a roller milling plant. It is a substantial rectangular building of brick six stories high built against the railway line. It has many arched windows at each level, and has a pleasing symmetrical appearance.

The mill has been in continuous use with little modifications for over a century and the company intends to use it into the foreseeable future.

Said to be the largest mill in New Zealand about the turn of the century, it is important as a fine working example of Timaru's milling industry, the largest in New Zealand during the wheat boom of the 1880s.

Internal features include a considerable amount of early machinery still in use, the polished wooden floors, and the spiral sack slide which connects all the floors. The slight alterations that have been made have been in keeping with the original style, and are in brick.

The integrity of this structure and its significance as the mill that revolutionised the flour milling industry in New Zealand make it an outstanding industrial structure.