 O Street Market previously consisted of between 12,000 sq ft (1,100 m2) and 12,500 sq ft (1,160 m2) on the main level and a 4,500 sq ft (420 m2) basement. The facade of the original one-story, rectangular brick building is 95 ft (29 m) wide and 150 ft (46 m) long. The most distinctive feature of this Gothic Revival section is the square tower on the northwest corner of 7th and O Streets NW. A gable roof and a monitor run the length of the remaining portion of the original facade. Including the tower, there are six bays on the 7th Street facade and five on the O Street facade. On the 7th Street facade, each bay features a pair of doors and transom windows. The bays on the O Street facade also have double doors and transom windows, except for the central bay, which projects and features a large window. The second and fourth bay transom windows on the O Street facade are surmounted by double-hung windows.
