On either end two three-bay–wide wings project four bays to the street. In the central 15-bay section, the middle three bays project forward slightly. The three-story building is faced entirely in Indiana limestone. The first story is, like City Hall's marble, rusticated, with the bays on the inside of the wings and the center pavilion made a series of segmented arches to give them an arcade appearance. On the east and west elevations only the interior bays are in arches. Within them are large six-over-six double-hung trabeated sash windows. Above them a cornice forms the base for fluted pilasters with Tower of the Winds capitals that divide the windows on the upper two stories. The second story windows are also sash, set in rectangular openings with sills and cornice caps on consoles topped with rosettes or oval patera. The middle bays of the wings are six-over-six in a slightly recessed arch with pedimented lintel on consoles. They have a small balcony with iron guardrails. A stringcourse around the building sets off the third story and forms its window sills. The central section has six-over-six with a plain surround. On both second and third stories of the wings' south face they are flanked by narrower four-over-four sash. The frieze below the roof cornice has rosettes or patera atop each pilaster. In the middle of the wings, and above the central pavilion, is a solid panel. That above the pavilion has "CHASE" carved in it. The north (rear) facade is less ornate but also well-delineated. A balustrade runs along the flat roof; there is a penthouse in the center. Four fluted Tower of the Winds columns rise from the balcony level of the central pavilion. The windows they divide are identical to those in the middle bays of the wing end second stories, with the third stories likewise fenestrated with shorter six-over-six. Two bronze lanterns flank the main entrance, with grille-covered four-over-four sash in the outside bays. The simple bronze door leads, as in City Hall, into a vestibule. Opposite it, across the central hallway, is the main staircase. At its landing is a multilevel stained glass window, with urns, foliate and architectural motifs flanking a central panel with another quotation from Lincoln: "Go forward without fear and with manly heart."