Exterior
Brick with stone dressings and plain tiled roofs. The pavilion plan comprises central entrance and administration block with chapel projecting to rear (originally with warm sea-water bath in its basement), linked by short corridor ranges to the hospital and convalescent blocks to either side. These run at right angles to the administration block, enclosing courtyards to front and rear.
Entrance and administration block: two storeys with attic and basement; symmetrically planned, but asymmetrically detailed, with central entrance in shallow projecting storeyed porch. The original doorway is up steps (and is now concealed by a further single storeyed porch addition) with a banded mullioned window below corbelled eaves band in upper storey and hipped lean-to pavilion roof. Slightly advanced outer gables to each side of the block, with mullioned and transomed windows (of 4-lights in right-hand gable, grouped 1-2-1 to left). Brick diaper decoration in gable apexes. Similar asymmetrical disposition of windows to either side of central entrance, with 2-light mullioned and transomed windows to left, single light windows to the right. Plain stone cornice over the central section, lettered ‘Royal Alexandra Hospital 1900’. Asymmetrical rear elevation, with chapel offset to east of centre, mullioned and transomed windows of varying width and height to right, stair tower with gabled roof to its left. Ribbed axial stacks. Narrow corridor blocks (both raised in height, and the western corridor doubled in width) link the administration block to the ward blocks to either side. The 3-storeyed ward blocks are symmetrically planned, but differently detailed, reflecting both their different original functions, and also the different phases in which they were built.
West Wing: symmetrically planned in its N-S axis about a central 4-storeyed pavilion block. This taller block is a 3-window range, with 3 gables advanced from its main hipped roof. Transomed windows of 2 and 2 lights in outer gables, and 3-storey bay window to centre, with 4-light mullioned and transomed windows, and balustraded parapet. Raised diaper brick-work in gable apex; axial stacks between the gables, and louvred and tiled spirelet on main roof beyond. Central gable to rear (east) elevation, and circular corner turret. Arcaded ward ranges to either side, with 6-bay first floor arcaded balcony/loggia (now glazed in), and former open balcony also now enclosed above. Ground or basement storey has a range of segmentally arched windows. The ward wings terminate in paired pavilion towers at either end, built to house toilet blocks, etc, with narrow windows paired in each face. Four-bay balconies like those on the side elevations run between the towers to N and S. Sash windows (with renewed glazing) in NE elevation.
East Wing: Planned in similar fashion to the west wing, with 4-storeyed central pavilion block and wards running N and S of it, but distinguished from the western block by the absence of integral balconies in its long elevations. Like the west wing, the N elevation has arcaded 4-bay balconies clasped between towers, but the E elevation (partly obscured by the addition of a closed-in fire escape) has a 5-window range (originally with sashes, but the glazing renewed in original openings) to either side of central block. This has single central advanced gable, with shallow balcony clasped between canted oriel bay windows in upper storey; mullioned and transomed windows variously grouped, to basement, ground and attic storeys. Drawings prepared by Paul Waterhouse in 1902 show that this range was intended to have balconies projecting from its W elevation, but it is not known whether these were ever built.
Chapel: brick with stone dressings including quoins and bands, and plain tiled roof. Two-light windows to nave (5 in all), and high gable to chancel, clasped by canted apsidal bays to either side, with paired foiled lancet lights. High-set 3-light decorated window in gabled 'east’ wall.