Honeyman and Keppie, dated 1890. Long classic 2-storey red ashlar office block.
Central 3-bay section: ground floor channelled ashlar, polished above. Advanced wide central bay with architraved and pedimented doorpiece supporting mermaids, set in arched panel; flanking statues of a mariner and a shipwright on trireme podia. Dentil cornice forms base for pedimented temple with 2 inner Corinthian columns fronting 3 large mullion and transom stained glass windows; balustrade over main entrance. 2 flanking cross windows with pilasters; 8 bays to either side with 1st floor pilastraded drawing offices. 3-storey tower at W end, Doric columned openings at 2nd floor. 6 bays to W with arched ground floor windows and blocked pedimented door dated 1890. 1st floor pilastrade. E end: E-facing pediment over pilasters, intersected by 1903 addition for gangway to new offices. 1-storey lodge with arched entrance and bipartites to E. 2 tall domed gatepiers, channelled at base.
Brick rear with ashlar band course and details. Curved section at E with arched 2nd floor windows and ashlar parapet. 3-storey square Italianate water tower with arched door and arched bipartite 1st floor window. Water tank, behind balustrade, is carried on brick piers and
Nearly all windows to N and S are original sash and case 2-pane below, 9-pane above. M-roof, slate and glass, modern behind pediment.
Interior: mosaic floor in vestibule with modern "GS" insertion, ornate wrought-iron banister to stairs. Board room: fine carved wooden fireplace with portrait of Sir Wm Pearce, walls two thirds panelled. Geometric plaster ceiling, Corinthian columns and stained glass windows.
Arched corridors. 1st floor an open drawing office with wooden beams to M-roof and cast-iron columns supporting valley.