21 University Square, Belfast

21 University Square, Belfast is a Grade B2 three-storey mid-terraced townhouse with attic, now used as university offices for the School of Creative Arts at Queen's University. Built in 1848–49 as part of a terrace constructed in stages between 1848–53, it is one of thirty former houses fronting University Square in South Belfast. The terrace was laid out by Charles Lanyon, though the architect of the actual buildings is unconfirmed. The building currently incorporates much of the ground and all upper floor accommodation of the adjacent No. 20 University Square via interconnecting doors, though these changes are largely reversible.

The front elevation faces south towards University Square, overlooking the Old Library (now QUB Student Graduate Centre) and the grounds of The Lanyon Building. It is a three-bay red brick facade built in Flemish bond. The ground floor features an entrance on the left side with an elliptical arched head, brick voussoirs, and moulded plaster reveal, deeply recessed with fluted columns of Doric-type capitals supporting a plain rendered entablature with moulded cornice. A plain glazed fanlight bears the number "21". The door is panelled painted timber, possibly original, with replacement ironmongery. A low painted stone plinth wall with an iron bootscraper flanks the left side. The right side of the ground floor has a single-storey flat-roofed canted bay window with painted render and square-headed window openings on each face, with roll-moulded stucco detail to soffit and reveal edges and a continuous painted stone cill. A painted stone rounded cornice sits above the windows, below painted stone coping of the parapet.

The upper floors have three regularly spaced window openings on both first and second floor levels, aligned vertically. Windows are timber sliding sash, single-glazed, with splayed brick heads and horns to ground and first floor levels. First floor windows are 1/1 sashes; second floor windows are 6/6 sashes, some containing historic glass. Bay windows are 1/1 type. Windows have continuous painted stone cill courses to the first floor (partly hidden behind bay parapet) and separate painted stone cills to the second floor. The pitched natural Welsh slate roof with red clay ridge tiles carries a brick chimney (rebuilt) with corbel detailing and seven yellow clay pots on the right side; no chimney exists on the left side. A small pitched roof dormer to the right has lead cheeks and natural slate roof with red clay ridge tiles, containing paired timber casement windows. The parapet has a hidden gutter, likely formed in lead. Painted metal downpipes with metal hoppers serve the parapet gutter and canted bay roof.

Access to the front is via six replacement reconstituted stone steps from street level, leading to a reconstituted stone paving slab landing, with modern metal railings either side. A disabled ramp with concrete sett surface is formed between brick walls with reconstituted stone coping. A low Flemish bond brick boundary wall with reconstituted stone coping and replacement painted metal railings fronts the street, though this is not original.

The side elevations are fully abutted by adjacent buildings: No. 20 to the west and No. 22 to the east.

The rear elevation faces north and is painted render. The main elevation is three storeys high with attic, exposed on the left side only. It features a single window opening to each level: a wide 2/2 timber sliding sash window on the ground floor, and 6/6 windows to first and second floor levels. A small rooflight sits to the left side of the rear roof pitch. The rear elevation is abutted on the right side by a three-storey return with hipped roof built at half landing height, which is in turn abutted by a two-storey return with hipped roof, finally abutted by a single-storey lean-to. Both larger returns have natural slate hipped roofs with red clay ridge tiles.

The east side of the three-storey return has randomly placed openings not aligned vertically. Ground floor features a flush timber door on the extreme left with two timber top-hung windows to the right. First floor has a 3/6 timber sliding sash window on the left and a top-hung timber window on the right. Second floor has a top-hung window on the left and a 3/6 timber sliding sash on the right. The east side of the two-storey return has a single large window opening on the ground floor with paired top-hung timber windows, and a single 3/6 timber sliding sash window to the extreme right of the first floor, which appears original.

The rear elevation exposed above the two-storey return's hipped roof has a single 4/8 timber sliding sash window (with narrow outer panes) on the right side. The rear of the two-storey return has a centrally located 3/6 timber sliding sash window above the lean-to. The lean-to's rear elevation has a single window opening at approximate middle (type not confirmed at survey).

All rear walls are painted render with painted rendered plinth. All windows have plain reveals and appear to have painted stone cills, except the lean-to which appears to have a painted concrete cill. All ground floor windows are behind metal bars. Painted metal rainwater goods are supported on metal rise and fall brackets. A shared rear yard is formed between the rear elevations of Nos. 21 and 22, linking into a larger network of alleyways and courtyards behind Nos. 20–24 University Square, enclosed on the north by modern buildings (The Black Box, part of QFT and School of Creative Arts at QUB) backing onto University Square Mews.

The roof is finished in replacement natural Welsh slate. A rooflight to the rear, likely modern, breaks the main rear pitch.