1 Clanbrassil Terrace, Clanbrassil Road, Cultra, Co. Down, BT18 0AR

1 Clanbrassil Terrace is a large three-bay, three-storey-over-basement terraced house built around 1860, located on the south shores of Belfast Lough to the east of Holywood. It is rectangular on plan and forms part of a distinctive terrace that is a good example of the large, prosperous seaside residence developed in the late nineteenth century as the suburbs of Belfast expanded following the arrival of the railway.

The roof is pitched natural slate. The brick chimneys have moulded rendered plinths, multiple flues and terracotta pots. Cast-iron ogee rainwater goods sit on sandstone dentilled eaves. The external walls are finished in ruled-and-lined render over sandstone. Windows are replacement 2-over-2 horizontal timber-framed sliding sash with horns (1-over-2 to the second floor), set in moulded reveals — those to the principal elevation in deep relief — with a continuous sill to the ground and first floors and projecting sills to the basement and top floor. Sandstone surrounds (rendered to the south elevation) have keyblocks, except to the basement windows. A smooth rendered plat-band runs between the ground and first floors.

The principal elevation faces north. Access is by fourteen stone steps — the final five contained within rendered masonry walls and piers topped by cast-iron railings — leading to a central three-quarter-glazed timber door with a transom light. To the right, a canted bay with four openings extends from basement to first floor. The second floor is five openings wide. To the left of the bay there are three openings on the ground and first floors. The basement has two 2-over-2 sash windows to the left and a timber door beneath the steps.

The rear elevation serves as the main entrance and is symmetrically arranged with three openings to each floor, plus a small oculus between the central and left window on the second floor. A central projecting porch at ground floor is accessed by four sandstone steps with squared and diamond terracotta tiles to the top step. The porch has a four-panelled timber door with bolection moulded-and-raised panels and a transom light, set into a moulded surround with a keyblock and moulded stringcourse at springing level, with a moulded cornice and dentilled eaves above. Two terracotta urns on plinths sit atop the porch. Steps down to the basement to the left pass through a cast-iron gate and railings, with squared and diamond tiles to the top step. To the west of the basement there is a diminutive 1-over-1 timber-framed sash window to the left and a timber half-panelled door to the right. Beneath the porch on both the east and west walls there are diminutive windows with projecting sills. To the east, the basement has a 2-over-2 sliding sash window.

The east elevation is abutted by the adjoining building, and the west elevation is abutted by a modern building.

The house has been modernised in recent years, resulting in a significant loss of interior detailing, although the internal ground plan has largely been retained. According to local historian C. Auld, the reception room ceilings originally displayed the expert stucco work of William Hayes of Marino, and although the house was built in 1867, the bathrooms were equipped with showers, bidets and comprehensive toilet facilities. The basement provided full culinary capacity with wine cellars and housekeepers' rooms.

The terrace does not appear on the second edition Ordnance Survey map of 1858 but is listed in the Annual Revisions of 1870 as "Clanbrassil Terrace," the name taken from Henry Hamilton, Earl of Clanbrassil, a local proprietor. At that time the terrace comprised four houses, all vacant, with the immediate lessor being James Connor; each was described as a house, yard and pleasure ground with buildings valued at £50. By 1877 this valuation had dropped to £42, perhaps as a result of an appeal. The valuation fieldbook notes of 1885 record that the first house in the terrace, adjoining number 1, was in ruins having burnt down, and by 1887 the current house had fallen in value to £35, likely as a consequence.

According to Auld, entrepreneurs George McAuliffe and James Connor commissioned cartographer J. Phillips to draw a pictorial map of houses and building sites to be let along the coast shortly after the arrival of the Belfast and Bangor Railway Company at Marino and Cultra stations. Clanbrassil Terrace is depicted on this map as having five houses, with those at the ends built at right angles to the central block. The house at the west end was destroyed by fire in 1878, and the proposed house at the east end was never completed, with protruding building stones indicating the intended additional residence. The developers reserved a nearby site for stables and outbuildings. A double-banked earth terrace rose from the sea-bordered lawns to conceal the basement windows. Tennis courts and a pitch-and-putt course spread before the entrance front, and a driveway was designed to surround the completed terrace.

By 1892 the occupier was William N. Pratt, and there were many subsequent changes of occupier indicating that the house was let. The valuation fell to £25 in 1910, but John Morrow of Ulster Tarpaulins, Cromac Square, who occupied the house in 1922, added a motorhouse and greenhouse, raising the valuation to £28 in 1923. The terrace first appears captioned "Princess Gardens" on the third edition Ordnance Survey map of 1900–02, but after 1933 the name reverted to Clanbrassil Terrace, as shown on the map of 1938–41.

In the 1930s the house was occupied by Elizabeth Morrow and leased from Sir Robert J. Kennedy, valued at £28 and later raised to £39. The accommodation at that time comprised two reception rooms, three bedrooms, a bathroom and WC on the principal floors, with three further bedrooms, a box room and tank room above, and a kitchen, scullery, pantry and WC in the service areas. The house was supplied with gas and had a well with pump, a greenhouse and a garage by the gateway. A valuer's note from this period reads: "Old fashioned, fronting close to sea. Looks suitable for seaside lodgings but no demand for such in area. Public footpath along side of garden at back."

By 1949 the house had been converted into three flats, all then vacant and leased from Frederick J. H. Nelson. A valuer described the ground and first floor flat as having numerous new concrete walls, hot and cold basins in the bedrooms, and perspex and fabric wall finishes in the bathroom, commenting it was "more in style of a 'maisonette' than a flat" with a "nice situation and outlook," and valued it at £44. William M. Lemon is listed in 1949 as the occupier of the basement flat, valued at £14; the valuer noted a hand pump for drinking water and described it as a "scullery-type house," with an old flagged floor in the kitchen, a new sink, fitted cupboards, an electric cooker, and cork floors elsewhere. In 1953 the basement flat was occupied by William Heathwood.

The modern end-terrace house to the south may be said to complete that part of the original terrace but presently makes it asymmetrical.

The terrace has a large lawn to the north, separated from the beach to the north and west by a rubble stone wall and steel three-bar railing. To the east, a fence and hedgerow separates the terrace from a neighbouring property. Access to the rear is through curved entrance walls with round rendered stone piers bearing projecting pointed caps on corbels. The boundary to the road to the south is a rubble stone wall with brick and stone coping.