42 Bluestone Road, Crossmacahilly, Portadown, Craigavon, Co Armagh, BT63 5SH

This is a storey-and-a-half, three-bay rendered and partially painted vernacular thatched house, believed to date from the second half of the 17th century, making it one of the oldest still-inhabited structures in Northern Ireland. It is of national interest on account of its age, rarity, surviving plan form, roof structure, and the evidence it preserves of an earlier shingle or tile roof covering predating the current thatch. It stands parallel to the Bluestone Road, separated from it by a short garden approximately two metres deep, and faces south. A cement-rendered wall topped with boulders runs along the roadside boundary.

The entrance is at the eastern end of the central bay, reached through a lean-to porch with a slated roof. The entrance door is match-boarded and painted, with no fanlight. To the east of the porch is a six-over-six sash window with a stone cill of standard Georgian size, which is notably large for a vernacular house. To the west are three further windows of similar type: one to the central bay and two in the western end bay. All openings, including the porch, are regularly distributed across the façade. At first-floor level there is a single narrow three-over-three sash window with a painted stone cill, tucked under the eaves at the centre of the elevation. The gables are unusually slightly higher than the thatched roof — approximately 75 millimetres — and cement parging has been applied to the junction between roof and gable. There are two rendered chimneys: one on top of the west gable, and the other aligned with the edge of the porch at the central bay. The west gable is unpainted and smoothly rendered in lime-rich sand and cement. Two small side-hung six-pane casements are located at first-floor level on the west gable, symmetrically placed about the centre of the façade and without cills.

The roof is currently scollop thatched in combed wheat straw. It is cut horizontally over the eaves and has a rounded head. Fixings are hidden except at the ridge and eaves. A single ligger of hazel secures the eaves, which are also wrapped in wire mesh. Since the time of survey, the ridge has been changed from a historically inaccurate block-cut form to a flush ridge, which is secured by two lines of liggers.

To the rear, a large single-storey kitchen return projects from the western end. It is slated with natural slates and fitted with cast aluminium rainwater goods. Two painted timber windows in a Georgian glazing pattern — top-hung casements — face west, and two similar windows light the rear gable. A similar window and a sheeted entrance door are on the eastern side of this return. Further to the east is a wide casement window in a similar style with sixteen panes to each side. A small additional return projects from the eastern end of the building; this has a small one-over-one sash with obscure glazing facing west and a corrugated metal roof. This return connects to a taller brick barn of similar height to the house, recently re-roofed with overhanging natural slate, which has two arched openings for farm use. A new barn-like structure has also been built to the rear, parallel with the house. It is constructed of brick with similar arched openings, and features dormers and a ridge ventilating cupola. Its design is considered slightly out of character with the vernacular style of the other buildings.

The roof structure is of particular historical and architectural significance. When inspected during renovation, regular mortices were found in the purlins, indicating that cross-bracing had once been provided. Marks were also found showing that rafters had been butted into the purlins to give a common upper surface. This complex form of construction is not required for a thatched roof, but is found on Waringstown House and Waringstown Church — buildings now slated but which may originally have been shingled, and both of which date from the mid-17th century. It is considered likely, on the basis of these structural parallels, that this building is of similar age and that it was originally roofed in slates, shingles, or tiles before being thatched. The first-floor beams are similarly notched to receive rafters and create a flat surface for the floorboards above, which is also an early joinery technique, though one recorded on buildings constructed up to the early 18th century. Dick Oram, who surveyed the house in 1993, observed that while the building has the appearance of a standard vernacular farmhouse at first sight, its original plan with interlocking doorways along the central axis and pegged timber framing of roof and floors belongs to what can only be described as a post-medieval tradition, making it of very special interest.

A building similar to the present structure, but with an L-shaped return to the southwest, is shown on the Ordnance Survey map of 1834–35, though it was not formally included in the contemporary valuation. By the revised Ordnance Survey map of 1860, a small return to the northeast is indicated instead. The property is recorded in the second valuation as a very old one-and-a-half-storey thatched building in good condition, leased by Thomas Twynam from the Duke of Manchester's estate, with a rateable value of £3 5s 0d. The Twynam family acquired the freehold in 1910 and were still in residence in 1929.

A discarded entry in the 1836 valuation refers to a public house on the old road to Portadown, occupied by a George Green, described as a very old thatched building in good condition, rated at £4 7s 7d and subsequently deemed under value, and therefore not given a reference on the accompanying map. It is described as measuring 49 feet by 20½ feet by 11 feet, with old thatched outbuildings measuring 45 by 12 by 5½ feet, 31 by 17 by 5½ feet, and 18 by 13 by 5½ feet. These dimensions suggest that this entry is indeed a description of the present building, and that it did function as an inn at that time. Local tradition holds that the building was known as the Red Cow inn, a tradition that is supported by this documentary evidence, although formal cartographic confirmation is lacking. John Rocque's map of 1760 does indicate a structure on what appears to be this site, though that map is insufficiently accurate to be relied upon, and no early maps of the townland have been found among the surviving Trevor or Manchester Estate papers.

The setting of the building changed little until the late 20th century. Craigavon New Town Commission compulsorily purchased the building in the 1960s and maintained it in reasonable condition. It was listed in 1981 and sold to its current owner in 1993, who undertook a programme of renovation that included relocating the spy window, sheeting in the ceiling, re-plastering, and extending the building to the rear with a new kitchen. The roof was re-thatched in 1981, and again in 1995 using wheat straw. The ridge was re-thatched in wheat straw in 2001.