20 Royal Exchange Square, Glasgow

The building comprises Nos. 2, 4, 6 Royal Exchange Square, Glasgow. It includes terraces dating from 1830, designed by David Hamilton and Robert Black, and later extensions by Hamilton and James Smith, based on a scheme by Archibald Elliot II. The terraces are three stories high and consist of shops and offices, with returns to Queen Street featuring attics to the end pavilions.

The building presents classical terraces to both the north and south sides of the square. The exterior is ashlar, mostly painted, with a pronounced base course. Modern shops occupy the ground floor, though the original frontages retain regular piers.

On Queen Street, the symmetrical pairs of elevations each have five bays. Panelled pilasters divide the bays at ground level, with tall, panelled doors in the outer bays. A frieze and cornice are visible above. Giant order Ionic columns extend from the first to the second floors, along with end pilasters, and moulded cill and lintel bands articulate the windows. A full entablature sits above, and windows are set within panels of the parapet, between panelled dies, with a blocking course above the central three bays.

The elevations facing Royal Exchange Square are arranged in a pattern of 11 bays, recessed between groups of five bays, with 13 bays set back and 11 bays boldly advanced. The eastern ends of each side, to the north and south, are decorated similarly to the Queen Street elevation but use Ionic pilasters instead of columns and have doorways placed in varying bays. Pends (passageways) are located at Nos. 7, 9, 10 and 22. The first-floor windows have simple architraves, with a frieze and cornice above the second floor, capped with a balustrade and dies (balusters are missing from the north side). A section of five bays to the west of the centre is slightly advanced and features giant order pilasters to the first and second floors, with attic windows in the parapet, mirroring the pavilions on Queen Street. The eleven western bays are advanced by a depth of one bay, featuring architraved windows on the first and second floors, and cornices to those on the first floor; an entablature and die, with a balustrade above, complete the design. Plate-glass sash and case windows are prevalent, with some small-pane windows also present. Slate roofs cover the structure.

Flanking Elliot's bank, two triumphal arches close the square to the west (located at 92-100 Buchanan Street). These arches are constructed of ashlar with keystoned semi-circular archways flanked by paired, fluted Ionic columns, supporting an entablature and parapet with coped end dies. Narrow pedestrian openings are positioned on either side of the archway.