20 Clarence Avenue, Londonderry

A late-Victorian mid-terrace townhouse built in 1900 to designs by R. E. Buchanan, designed in the Arts and Crafts style. The house is two bays wide and three storeys tall, with a rectangular plan and a projecting rear return constructed at half-landing level.

The principal elevation faces south onto Clarence Avenue and is constructed of Flemish bond brickwork. The ground and first floors feature a two-storey canted bay, above which rises a rectangular gabled bay on the second floor, cantilevered on large timber brackets with carved timber corbels on either side. The gable displays diagonal half-timber panelling beneath a plain wide painted timber fascia board.

All openings are square-headed. The entrance doorway, positioned two steps up, has a moulded cornice supported on console brackets mounted on moulded pilasters flanking a pair of panel fielded timber half-leaf doors. Above the doors is a stained glass square-headed fanlight. The windows on the principal elevation are timber sliding sashes with 1/1 panes; those to the canted bay on the ground and first floors and the window above the first floor entrance door have stained glass upper lights. The box window on the second floor has 8/2 panes, whilst the single sliding sash above the entrance door on the second floor has 4/2 panes. Painted rendered bands mark the window heads on the ground and first floors, with painted sill courses to the first and second floor windows.

The east and west elevations are built against adjoining houses (No. 18 and No. 22 Clarence Avenue). The north elevation is rendered in unpainted cement and rises three storeys; it incorporates a two-storey rear return built at half-landing level, featuring a small red-brick chimney rising from the gable-end. Below this steps down a single-storey duo-pitched abutment with smooth rendered unpainted finish. Windows to the rear elevation include 2/2 pane timber sliding sashes on the second floor of the rear return, timber casement windows to the lower floors, and uPVC casements to the abutment. A margin-paned sliding sash window within the west face of the two-storey return overlooks the yard of No. 18.

Within the yard, a single-storey lean-to painted white abuts the return towards No. 22, with a flush painted door to the north face featuring a glazed top panel.

The roof is pitched with natural slate and terracotta clay ridge tiles. A large red-brick chimney stack with dog-toothed corbelling rises from the east side, centred on the ridge with clay pots. Cast-iron guttering and circular downpipes serve the front elevation.

The house forms part of a terrace of eleven similar buildings lining the north side of Clarence Avenue on a steep gradient. It sits within the Magee Conservation Area, set back from the pavement with a small front garden enclosed by a low red-brick wall with painted metal railings. A rear yard is bounded by smooth rendered walling topped with precast concrete coping, accessed via a timber sheeted gate (painted) within a square-headed opening. The yard backs onto a shared alley with the University campus beyond.