10 Clarence Avenue, Londonderry

10 Clarence Avenue is a late Victorian mid-terrace townhouse of two bays and three storeys, built in 1900 to designs by Robert Eccles Buchanan, a local architect and civil engineer active in Londonderry between 1887 and the 1920s. It sits on the north side of Clarence Avenue within the Magee Conservation Area, set back from the pavement behind a low red-brick wall with a small front garden. The house is rectangular on plan with a projecting rear return built at half-landing level.

The principal (south) elevation is finished in Flemish brick bond and displays a strong Arts and Crafts character. To the right of the façade, a two-storey canted bay rises through the ground and first floors, surmounted at second-floor level by a rectangular gabled bay that is cantilevered on large timber brackets with carved timber corbels to either side. The gable is decorated with vertical half-timber panelling and finished with a plain wide painted timber fascia board and a terracotta finial at the apex. A painted rendered band runs across the ground and first-floor window heads, with a painted sill course to the first and second-floor windows.

All openings on the principal elevation are square-headed. The entrance doorway is reached by five steps and features a moulded cornice supported on console brackets, with moulded pilasters to either side of a four-panel fielded timber door with a stained glass fanlight above. The canted bay windows on the ground and first floors, and the window above the door at first-floor level, are 1/1 sliding sashes with stained glass upper lights. The second-floor windows have been replaced with uPVC, which detracts from the overall character.

The north (rear) elevation is three storeys, rendered and finished with uPVC casement windows to the rear return and the small single-storey extension at the base of the return. The main rear elevation retains 2/2 timber sliding sash windows. The rear return is finished in painted render at ground-floor level only and has a small red-brick chimney rising from its gable end. The single-storey extension has a slated duo-pitched roof with a rendered finish. The east and west sides of the house abut the adjoining properties at Nos. 8 and 12 Clarence Avenue.

The main roof and rear return are covered in natural slate with terracotta clay ridge tiles. A large red-brick chimney stack with a dog-toothed corbel and clay pots rises from the east side, centred on the ridge. Cast-iron guttering and circular downpipes serve the front elevation. Conservation work carried out in 1987 included the reconstruction of this chimney stack and the reslating of the roof in second-hand slate.

To the rear, a slide-back timber door painted red spans almost the full width of the yard, with a plain rendered surround and corrugated metal overhanging from a lean-to roof on its reverse side. The yard backs onto a shared alley with the University campus beyond.

No. 10 is one of a terrace of eleven similar houses — Nos. 2–22 Clarence Avenue — lining the north side of the street on a steep gradient stepping down towards the river. Each house in the row retains its ornate doorcase and canted bay window, with alternating diagonal and straight half-timbered gables to cantilevered square bays above. Historians have described Buchanan's terrace as "generously proportioned" and "excellently modelled," and it has been identified as one of the architecturally finest groups of townhouses in the city. The Conservation Guide noted that Clarence Avenue "is very unified architecturally and is virtually intact." The terrace was listed in 1979 and incorporated into the Magee Conservation Area in 2006.

Clarence Avenue was originally laid out in 1897 and was named in memory of Prince Albert Victor, the last Duke of Clarence and son of King Edward VII, following his death in 1892 at the age of 28. The northern terrace of Nos. 2–22 was erected in 1900, built in tandem with the development of the Magee College campus. The wider northward expansion of Londonderry had begun in the mid-19th century with Georgian-style terraces on Great James Street, Queen Street and Clarendon Street, and continued through a period of sustained economic prosperity from the 1860s to the end of the 19th century. From the 1880s, new red-brick dwellings on College Terrace and Clarence Avenue were built to provide accommodation for students and staff of the college.

No. 10 was initially valued at £26 and was originally owned and occupied by William Moore, a local grocer with a shop on Rossville Street. The 1901 census described the property as a first-class dwelling consisting of ten rooms. The Moore family continued to own No. 10 until at least the 1970s, though the house was leased to other tenants from the 1930s onwards. The property's rateable value was increased to £37 under the First General Revaluation of Property in Northern Ireland (1936–57) and further raised to £42 by the end of the Second Revaluation in 1972.