Exterior
High-Gothic Revival style and comprising an L-shaped 3-storey with basement main range on the corner of Bridge Street and Pavilion Hill, and a later 2-storey with basement wing facing Pavilion Hill. Both are of coursed rock-faced stone with freestone dressings, with renewed slate roofs, of steep pitch to the original range, behind coped gables. The later wing has a slender lead spirelet with weathervane dated 1912.
The entrance is in Pavilion Hill where the earlier range consists of 3 asymmetrical bays and is built on a steep slope. The later wing is to the L. In the original range the doorway in the higher entrance bay to the L is beneath a gabled hood, which has foliage stops and a crocketed finial. Double panelled doors have raised fields to the bottom panels. The surround has a ringed nook shaft with foliage capitals and a lintel engraved 1884. A pointed overlight has a foiled circle with patterned glass. A brass plaque above the arch records the opening of the building in 1884. The entrance bay has shallow gabled buttresses and stair windows above the doorway. The lower landing has a 3-light window with coloured glass and a moulded surround with shafts and crocket capitals, and is partly obscured by the gabled hood over the entrance. Above the lower window is a band of shields and alternate square foliage panels. The upper landing window is 2-light and has shafts with crocket capitals and a pointed arch over a tympanum with foiled circular light with coloured glass. A hood mould is a continuous with an impost band. Arcaded eaves, with gargoyles at the corners, are beneath a coped parapet.
On the R side of the entrance is a recessed bay and then a gabled end bay. The centre recessed bay has a blocked 3-light mullioned basement window, while in the lower storey is a 3-light mullioned and transomed window with coloured glass above the transoms. The first floor has a 3-light window in a surround with ringed shafts with foliage capitals, and trefoil heads incorporating patterned glass. In the upper storey the centre bay has 3 sash windows below the eaves cornice, and a large glass panel in the roof lighting the original art room. The R-hand end bay has 2 basement windows in stone surrounds. In the ground and first floors is a shallow castellated 2-storey 3-light oriel window corbelled out on a thin band of relief foliage beneath the sill. In the lower storey the window has coloured glass above the transom, while in the middle storey is a surround with ringed shafts with foliage capitals, and trefoil heads incorporating patterned glass. In the upper storey is a 2-light geometrical window with ringed shafts and foliage capitals. All the windows incorporate 2-pane sashes, some of which were renewed in 2001.
In the 2-bay Bangor Street elevation the basement (10 Bangor Street) has thin pilasters which have end foliage capitals (partly missing on the R side) below consoles enriched by foliage and trefoil panels. The consoles are crowned by prominent seated dragons (missing to the centre). The original shop front has a moulded cornice over a blank stone fascia, but otherwise the shop details are late C20. Above the basement are castellated 2-storey 3-light oriel windows with detail similar to the Pavilion Hill elevation. The upper storey has 2-light geometrical windows carried above the eaves under coped gables on moulded kneelers. The moulded cornice incorporates a corbel table.
The later wing on Pavilion Hill is 3 asymmetrical bays, including a projecting and wider central bay. The 2-window R-hand bay has a cross window and a cross window to the R, both incorporating 2-pane sashes and above corresponding blocked basement windows. The central bay has a double panelled door under a mullioned overlight, but cut down from an original cross window, with another cross window to its R. The L-hand bay has a single cross window. The upper storey has windows lighting the council chamber similar to those in the lower storey, but with sill band and incorporating patterned glass. The central bay is further enriched by a thin band of foliage beneath the sill, while the windows are recessed beneath a blind pointed arch with hood mould and foliage stops. In the tympanum are 3 blind panels, the central having a circular window in a cusped surround, while the outer panels have shields bearing 3 leopards, arms of Edward I. A coped gable has a central attached shaft on a shield corbel, and has a crocketed pinnacle. The roof in the outer bays is behind a coped parapet on a moulded eaves cornice incorporating stone rainwater head.
The 2-window L gable end of the Pavilion Hill elevation is pebble-dashed. A corbelled first-floor stack bears a shield in relief, while its upper portion is of rock-faced stone. In the lower storey are 3-light mullioned and transomed windows, while in the upper storey are smaller 2-light mullioned windows, of which the R-hand retains its original intricate glazing pattern. The earlier range has a brick rear elevation.