Exterior
A symmetrically planned barrack block, composed of a square 3-storey central keep with long and lower 2-storey wings and projecting end bays with crow-stepped gables and moulded kneelers. Of snecked rock-faced stone with Bath stone dressings and quoins, and slate roof. Windows have plain mullions and transoms and incorporate 2-pane sashes with marginal glazing bars. The keep has projecting corner turrets, higher on the R side, and embattled parapet on a corbel table. A central through passage has a segmental arch with 2 orders of chamfer, which has a doorway L with shouldered lintel, and a narrow guard-room window to the R. The middle and upper storeys have 3-light windows flanked by single-light outer windows. The L-hand turret has 2 windows in the lower storey, stepped stair lights in the middle storey and 3 narrow windows to the upper storey under a relieving arch. The R-hand turret has 3 windows in each storey, narrower in the lower storey, and 2 vents in the gable.
The 8-window wing to the R has plain cornice and corbels, single, 2-light and 3-light windows, and R of centre is a replaced panelled door below an overlight. The 2-window projecting gable at the end has 3-light windows in the lower storey and 2-light mullioned and transomed windows above. The gable has stepped vents. A single-storey projection against the end wall has a lean-to behind.
The 9-window wing L of the central tower has single, 2-light, 3-light and 4-light windows, while L of centre are double panelled doors with side and mullioned overlight, all with marginal glazing bars. A shallow projection under a hipped roof is at the R end, in the angle with the central tower. The L-hand projecting end bay has three 2-light windows under relieving arches in the upper storey. The central 2-light window in the lower storey has been cut down for a doorway. Of the flanking single-light windows, the L side has been cut down to make a doorway and subsequently blocked. An added 2-window projection is set slightly back. It has a roof concealed behind a coped parapet. A 2-light window is on the R side, and a small-pane sash window to the L. The 5-window L end wall has replaced single-light windows, and a central doorway with overlight (both boarded up at the time of inspection).
The rear elevation faces the parade square. The central keep has a rear elevation similar to the front. Its central passage is flanked on each side by doorways with shouldered lintels, above which are cross-shaped lights. The turret on the L side has stepped stair lights in each storey, and in its L side wall. The R-hand turret has 3-light windows, with similar windows in the R side wall.
The 9-window wing on the R has single-, 2-light and 3-light windows, with steps up to ground-floor doorways, and steps down to the armouries in the basement. A central doorway has a diagonal boarded door, and R and L of centre are half-lit doors with diagonal boarding. The end gabled bay has two 2-light windows in each storey, R of which the original elevation continues with a single 2-light window, beyond which is the added projection, with fielded-panel door. The 9-window wing on the L side of the keep has 2 equally placed 2-storey embattled porches to the original officers' quarters. Between these porches are 2-light and single-light windows, with half-lit boarded door to the R end. The porches have steps up to a doorway with shouldered lintel leading into an open porch. Inside are double half-lit doors with diagonal boarding. In the upper storey is a 3-light window with stepped central light above a transom, and embattled parapet. Further L are single and 2-light windows, then another similar projecting bay, with 2-light and single-light windows further L. The gabled end bay has a recessed porch on the L side with shouldered lintel, inside which are half-lit double doors and overlight. To the R of the porch is a 3-light window. In the upper storey are a 2-light window L and 3-light R, with 3 stepped vents in the gable. A lean-to set back on the L side has a sash window to the lower storey and attic, a diagonal-boarded door and overlight to the L, and a projection with 2-light window.