Mill Dam House

Mill Dam House is a building that originally served as barracks and offices for the Royal Engineers, dating back to 1846 and restored in 1990. It is constructed of red brick with grey header bricks in Flemish bond and features a low pitched hipped roof made of Welsh slate, reflecting a late Georgian style. The layout includes a central open courtyard with a staircase and single-depth rooms on three sides.

The exterior stands two storeys tall and comprises seven bays, with the central three bays projecting. The symmetrical front is flanked by matching sides. At the center, there is a two-leaf six-panelled door with a fanlight, set beneath a gauged brick round arch and located in a later projecting porch that has a stone-coped facing gable. Above the porch is a moulded stone apex inscribed with the words 'R.E. Office'. On either side of the door, there are six 12-pane sash windows, each positioned under gauged brick flat arches. The first floor features seven similar sash windows. The central projection has a stone band at the first floor level, a brick band above it, and a facing stone gabled parapet. The flanking bays have a brick band, a stone cornice, and a rendered block parapet. The left and right returns are similar, each with central pediments. On the right return, there is a later six-flush panel door with a margin-glazed overlight.

Inside, the building retains a largely complete interior, highlighted by a large open central stair hall. This hall contains an impressive cast-iron Imperial stair, with galleries on three sides at the first floor level and stairs leading up on the fourth side. The stair features cast-iron risers, tread balusters, and a handrail, along with original joinery and plasterwork.

The specific purpose of this well-planned building is not entirely known, and Engineer's barracks are considered rare. The patterned brickwork is reminiscent of that found on the circa 1810 stores at the former Ordnance yard at Gunwharf, making it of considerable historic interest due to its unusual plan form and staircase.