Rockbrook House, 4 Temple Road, Upper Ballinderry, Lisburn, County Antrim, BT28 2PD

Rockbrook House is a symmetrical three-bay, two-storey house built around 1830, located east of Temple Road in Upper Ballinderry. The building stands on a rectangular plan with a two-storey return extension built around 1840 and a single-storey modern extension added around 2000 to the internal angle at the rear.

The house features a pitched natural slate roof with ridge crestings and rectangular smooth rendered corbelled chimneysstacks, each with three octagonal decorative clay pots. Half-round cast-iron rainwater goods complete the roofline. The walls are finished in roughcast lime render with painted detailing.

The principal south-facing elevation displays high-quality architectural detailing. The ground floor windows are 2/2 horizontally divided timber-framed sliding-sashes contained within paired round-arched headed openings with moulded architrave terminating at a moulded stop at the centre, with painted projecting masonry sills. The first floor windows are diminutive 1/1 sliding-sashes set within elliptical-arched headed openings with projecting masonry sills and plain painted reveals. The central feature is a raised panelled timber door with brass knob, knocker and letter box, surmounted by an elliptical-arched radial fanlight. The door is flanked by raised pilasters, side panels and horizontally divided sidelights all contained within an elliptical-arched headed opening with moulded architrave and key block supporting a brass downlight. A single stone step provides access. The door opening is flanked by the paired round-arched headed windows at ground floor, with three windows at first floor completing the composition.

The west gable is blank, facing directly onto an adjacent perpendicular outbuilding. Rear windows are square-headed 1/1 timber-framed sliding-sashes with projecting masonry sills. The two-storey return at the rear employs the same roof detailing as the principal block and is abutted at the east by a modern single-storey extension with flat roof containing uPVC window and door with uPVC rainwater goods. The return's north gable comprises an offset external gable chimney stack, whilst its east elevation features two square-headed enlarged uPVC windows at ground floor and two round-arched headed windows at first floor.

The house is set in a rural location forming part of an agricultural complex. Two perpendicular aligned earlier outbuildings stand to the west, with a barn to the south-west. Various early outbuildings have been extended and largely rebuilt to the north. A paved forecourt at the south is accessed through wrought-iron entrance gates supported on square roughcast piers with pyramidal stone caps.

Despite internal alterations and later modifications, the retention of the principal fenestration and high-quality detailing of the south elevation have maintained the historical and architectural significance of this late Georgian house, which retains a good rural setting.

Historical records show that Rockbrook House appeared on the first edition of the Ordnance Survey map in 1832 as part of an extensive complex of seven small buildings. The Townland Valuation of the 1830s recorded the property as occupied by William C. Brown, with the main house classified as a 1B dwelling measuring 29 feet by 22 feet and 13 feet high. Two smaller houses were also listed, each valued at less than £1. Outbuildings included a barn, byre, cow house, piggery and potato house, with the entire farm valued at £7 15s 5d. By 1857, the second Ordnance Survey map depicted alterations: where seven similar-sized buildings had previously stood, the farmstead then comprised four larger buildings and three small outoffices. Griffith's Valuation of 1856–64 recorded a slightly decreased value of £6 for the main house, with five small houses and offices at varying values under £1.

In 1878 the house came into the possession of William Cambridge, residing there until 1883 when James Johnston briefly occupied it before being replaced in 1885 by George Usher. In 1885 all the smaller houses and offices were demolished except one valued at £1. The third edition Ordnance Survey map of 1900–01 depicts a much-altered farmstead comprising three large structures arranged to contain a small courtyard. George Usher remained in residence until records ended in 1929. Census records from 1901 describe him as an 84-year-old widowed farmer living at Rockbrook with his two sons and two daughters. The house was then recorded as a second-class dwelling comprising nine inhabited rooms, with outoffices including a stable, cow house, calf house, dairy, piggery, fowl house, boiling house, barn, potato house and shed. By 1911 his son, also named George, had taken over the house following his father's death, aided by his brother John Edward and sister Caroline Victoria Usher in managing the farmstead. The farm remains occupied by a member of the Usher family.

The house was listed in August 1983. Renovation works proposed in 1984 were carried out in 1987. A single-storey extension was added around 2000.