Harty House, 25 Ballynahinch Street, Hillsborough, County Antrim, BT26 6AW

Harty House is an attached, asymmetrical two-storey stucco terraced house built around 1820, located on the south side of Ballynahinch Street in Hillsborough, to the east of Arthur Street. It is rectangular in plan, facing north, with a two-storey rear return. The house does not appear on an 1803 town plan of Hillsborough but is shown on the first Ordnance Survey map of 1833, depicted as an oblong building situated halfway up the Ballynahinch road, immediately next to the entrance of the town's Pleasure Grounds.

The fine decorative façade appears to be a late 19th-century alteration to the earlier structure. The interior has been largely altered, but the exterior retains most of its historic character.

The roof is finished in natural slate with black clay ridge tiles. Rendered chimneystack rise from each gable end, fitted with terracotta pots, and the rainwater goods are cast iron. The external walls are painted in a ruled-and-lined rendered finish — that is, render scored to imitate ashlar stonework — with rusticated rendered quoins and a smooth rendered plinth course.

Window openings are square-headed, with moulded architrave surrounds and keyblocks to the ground floor. The sills are painted masonry, and the windows themselves are early 20th-century six-over-six timber sash windows with exposed sash boxes. The front elevation is four windows wide and asymmetrical. The door opening is round-headed and contains a replacement hardwood panelled door set within an architrave surround broken by a keystone, with a replacement semicircular fanlight above. The doorcase is flanked by plain pilasters and a pair of oversized scrolled foliate console brackets supporting a large cornice and canopy.

A ceramic Blue Plaque affixed to the wall reads: "Sir Hamilton Harty 1879–1941 Musician and Composer Lived here."

The east gable is blank and is abutted by a decorative iron pedestrian gate supported on a tall rendered pier, with a screen wall to the side garden. The rear elevation was not inspected. The west gable has a single first-floor window opening filled with glass bricks. No. 23 Ballynahinch Street abuts the rear section of this gable. To the east, modern decorative steel gates give vehicular access to the rear and to the neighbouring modern house, No. 27.

The Townland Valuations of the 1830s record the house as valued at £8 and occupied by a Mr Aaron Hunter. By the time of Griffith's Valuation in 1861, the property had come into the possession of Captain James Balcombe, who had served with the 57th Foot Infantry during the Crimean War (1853–56). At that point the house was valued at £18, measured 14 yards by 6 yards, and was classified as a two-and-a-half-storey, class 1B+ dwelling. Balcombe paid rent of £1 10s. to the Marquis of Downshire and lived here until his death in 1872, after which the house passed through a number of occupants over the following two decades.

The house was traditionally provided by the Marquis of Downshire as the residence of the organist of the nearby St Malachy's Church of Ireland. Historical records indicate that a Mr W. Penry Williams held the organist's position between 1856 and 1878, and Annual Revision records show five separate occupants between 1861 and 1889, none of whom appear on the known list of organists. In 1878, William Harty became the new Parish Organist. He and his family, including his infant son Hamilton, had previously lived at 14 Main Street, but moved to 25 Ballynahinch Street some time after William took up the organist's post. The 1901 Census records William Harty (aged 49), a Dublin-born Professor of Music, living here with his wife Annie (aged 47) and several of their children. The building was then recorded as a first-class dwelling with 13 inhabited rooms; the outbuildings at that time included two stables, a cow house, a calf house, a fowl house, and a barn, though by 1911 only one stable, a coach house, a harness room, and a cow house are recorded.

William Harty does not appear in the Annual Revisions as occupant until 1889 and remained until 1920, when a Mr John Vine took the house, followed in 1923 by a Thomas Forster — both of whom are recorded as past organists (Vine 1918–1921; Forster 1921–1932) — suggesting that the formal tradition of letting the house to the Parish Organist may only have been established after William Harty's tenure. It is also noted that a direct path was created through the adjoining Pleasure Grounds, allowing the organist to pass through his garden and on through an "Organist's Gateway" beside the Parish Church, giving quick and unobstructed access.

The most celebrated resident of the house was the composer and conductor Sir Herbert Hamilton Harty (1879–1941). From the age of ten, Hamilton Harty assisted his father in his duties as Church Organist. At twelve he was appointed organist of Magheragall Parish Church, and at sixteen he became organist and choirmaster of Christ Church in Bray, County Wicklow. He rapidly established himself as one of the most accomplished Irish musicians of his era, both in Ireland and in England. At the age of twenty he performed before Queen Victoria, accompanying the celebrated singer Madame Ella Russell. He went on to conduct the London Symphony Orchestra and in 1920 became permanent conductor of the Hallé Orchestra. In 1925 he received a knighthood for his services to the arts, and in 1934 was awarded the Gold Medal of the Royal Philharmonic Society, then recognised as the highest honour in music. His compositions include An Irish Symphony, The Children of Lir, and The Mystic Trumpeter. Harty died in 1941 at the age of 61; his ashes were brought to Hillsborough and interred in the Parish Church. The house was subsequently renamed Harty House in his memory.

The building was listed in January 1976. Since then it has been renovated in 1976 and again in 1981, with chimney and exterior repairs carried out in 1992 and a further renovation in 1994. The property sits within a conservation area and is in private residential use.