18 Main Street, Hillsborough, County Down, BT26 6AE

18 Main Street is a mid-terrace, symmetrical three-bay two-storey rendered house of the early nineteenth century, built between 1800 and 1819 and situated on the east side of Main Street, Hillsborough on a sloping site. The building faces west and is rectangular in plan.

The house retains its early nineteenth-century external appearance. The pitched roof is covered with natural slate and fitted with black clay ridge tiles. A rendered chimneystack with clay pots sits to the north. Cast-iron guttering on iron brackets and cast-iron downpipes run along the eaves. The walling is painted ruled and lined render with a stepped plinth course and rusticated render quoins.

The front elevation features three bays with square-headed window openings. The windows are original tripartite timber sashes with cylinder glass and painted masonry sills, characteristic of Wyatt style. The central bay contains a round-headed door opening with a deep moulded architrave surround. The door itself is timber with four raised and fielded panels and brass furniture. A spoked fanlight sits above it, and there is a single granite step and wrought-iron bootscraper at the entrance.

The building is mid-terrace, abutted on the north gable by adjoining property No. 16 and on the south gable by No. 20. The rear elevation includes a stairhall projection with a catslide roof and a pair of lean-to extensions to either side. Early 6/6 timber sash windows with exposed sash boxes are present on the upper level. The ground floor has replacement timber casement windows and a pair of replacement glazed timber panelled doors.

The interior retains some interesting elements of the late Georgian period despite changes to the internal layout. The basement level is evident from historical records, and the 1901 Census recorded the house as a first-class dwelling of 10 inhabited rooms with two out offices.

The building was not shown on a map of circa 1800 but first appeared on the first Ordnance Survey map of 1833. Historical records indicate that in the 1830s the house was occupied by Dr. Gilpin and valued at £8 8s. The Griffith's Valuation of 1861 shows Mrs. Alice Kidd as occupant, with the house valued at £13 and classified as 1B+ dwelling measuring 10 by 8 yards and two-storeys high. Alice Kidd, described as a retired grocer in the 1901 Census, occupied the house until 1909, having been widowed in 1860. Her husband Robert Kidd was a local haberdsher whose will records effects of around £800. Hugh S. Jefferson, Alice Kidd's nephew, became occupant in 1909 and remained until 1930. The house was formerly used as a grain shop and forms part of several dwellings on Main Street previously employed as commercial premises. The building was listed in 1976 and extensively renovated in 1983.

To the rear of the property is a cobbled yard with original rubble stone and brick walling. A two-storey rendered former outbuilding with natural slate roof stands here, featuring replacement timber casement windows and a central arched passageway giving access to the original landscaped garden beyond. This outbuilding was recorded as a rear office on the second edition Ordnance Survey map of 1858 and by 1911 was being used as a stable and barn. The former stable and storeroom remain well-maintained.

The property forms an important component of the historic streetscape, situated as part of a terrace of varying house types lining the east side of Main Street. The building is within a conservation area. The listing extends to the house, outbuildings, and walling.