18 Clarence Avenue, Londonderry

18 Clarence Avenue is a three-storey, two-bay red brick terrace house built around 1900 to designs by Robert Eccles Buchanan. It forms part of a terrace of eleven similar houses lining the north side of Clarence Avenue in the Magee Conservation Area, set back from the pavement with a small front garden and a small paved yard to the rear. The yard backs onto a shared alley with the University campus beyond.

The building is rectangular on plan with a full-height gabled bay and a three-storey rear return. The pitched roof is covered in artificial slate with terracotta ridge tiles. A profiled red brick chimney-stack rises from the east side, and the building has replacement metal rainwater goods (uPVC rainwater goods to the rear).

The walling is laid in Flemish bond throughout with continuous painted flush masonry lintel courses. Window openings are square-headed with timber sliding sash windows. The principal south elevation is two bays wide in Flemish bond brick. The right bay comprises a two-storey canted bay surmounted by a rectangular gabled bay to the second floor that is cantilevered on large timber brackets with carved timber corbels to either side. The gable has vertical half-timber panelling with a plain wide painted timber fascia board and a terracotta finial to the apex. The ground and first floors have 1/1 timber sliding sash windows with leaded coloured glazing to the upper sashes. The second floor has a 4/2 timber sliding sash window, with paired 8/2 timber sliding sash windows to the projecting bay. A square-headed door opening to the ground floor contains an original diamond-panelled raised and fielded timber door flanked by flat-panelled pilasters and corbels supporting a lintel cornice with a leaded coloured glazed fanlight over. The door opens onto a concrete path and paved front area enclosed by a low red brick wall to the street.

The east side elevation is abutted by the adjoining building at No.17 Clarence Avenue. The north rear elevation is abutted by a three-storey gable-ended return to the right. The exposed section to the left has 1/1 timber sliding sash windows to the ground and first floors and a 2/2 timber sliding sash window to the second floor. The return has square-headed window openings with painted masonry sills and largely 2/2 timber sliding sash windows with slender ogee horns. The return is abutted by a single-storey pitched roofed addition with an artificial slate roof and red clay ridge tiles. The east face of this addition comprises an original vertically-sheeted timber door to the left, flanked by a 1/1 timber sliding sash window to the right, and two door openings to the far right. The west side elevation is abutted by the adjoining building at No.19 Clarence Avenue.

The rear boundary wall is smooth rendered without paint and coped with precast concrete, with a sheeted timber gate within a square-headed opening.