The treatment of the rugged two-story masonry base of the former Rockville Mill is unusual for such architectural refinements as the stringcourse projecting between the stories and the hierarchy of window sizes, with larger openings below, smaller above. The attic story, with a broad monitor in clapboard, was rammed onto the upper story during the building's rehabilitation into office space and seems mocking, especially in contrast to the simple, low-gable roof with clerestory monitor that originally capped the composition. Few of its period and size exist, so its preservation for modern office use is welcome, even though it is now further diminished by a rather too extensive parking lot.