Ballywilliam House, 38 Ballygowan Road, Ballywilliam, Comber, Co. Down, BT23 5PG

Ballywilliam House is a substantial and rambling two-storey farmhouse situated in a hollow between the Ballygowan and Old Ballygowan Road, approximately 1.5 miles south of Comber, County Down. The property is built around a modest two-storey house from the 1780s, which was extended and renovated around 1850, with further extensions added in the late 19th and 20th centuries.

The main original section faces south with a symmetrical front façade. At ground floor centre is a large flat-roofed porch with extensive glazing, added sometime after 1858. The porch front features a central timber-panelled double door reached by two stone steps, flanked by large four-pane windows with panelled pilaster jambs; the porch sides are similarly glazed. The porch is topped with a cornice and blocking course. Either side of the porch are sash windows with vertical glazing bars and simple moulded surrounds. The first floor contains three similar but shorter windows, all resting on a cill course. The east gable has a ground floor window matching the porch design but without surround, and a first-floor sash window with Georgian panes to the right.

The east gable merges with the east façade of a long two-storey return set into the slope; its north end contains only a single storey (added around 1925, which is actually part of the first floor). The ground floor of this façade has two sash windows with Georgian panes (8 over 8) and two smaller windows above at first floor. To the right are first-floor windows only: a large mullioned and transomed window to the left and an oriel window with a hipped roof and similar frame to the right. The north gable of this return is single storey and features a projecting hipped roof conservatory or porch with mullioned and transomed windows and glazed double doors.

The west elevation is complex. The west gable of the main front section has a single-storey lean-to cloakroom (added around 1925) with modern metal windows attached. This cloakroom connects to a large two-storey gabled housekeeper's section, which is itself attached to the west face of the long rear return, enclosing a small yard. Above the cloakroom section, the gable proper has a first-floor sash window with Georgian panes to the right and a small attic sash window above.

The enclosed yard is bounded on the south by a short section of the main house's rear façade and on the east by the west façade of the long return. This portion has two ground-floor sash windows with Georgian panes flanking a timber-sheeted door, and two similar but shorter windows above at first floor. To the north, the yard is enclosed by a two-storey gabled extension linking the west façade of the return to the east façade of the housekeeper's section. The extension's first-floor south façade has a small bathroom window with a modern frame; the ground floor has a timber-sheeted door with a four-pane fanlight leading to a small store. A flight of stone steps leads to an intermediate level doorway into the housekeeper's section.

The housekeeper's section's south façade has several metal casement windows, while its north façade (built into the slope) has a curious hipped roof half-dormer or oriel window with a mullioned and transomed frame. The north gable of the extension between the housekeeper's section and return has a small mullioned and transomed window with a small loft opening above. To the north, the west façade of the long return has two large mullioned and transomed windows.

The house façade (excluding the housekeeper's section) is finished in lined render with moulded quoins to the front. All roof sections are covered in Bangor blue slates. The original front section has an overhang to the gables with shaped barges. Chimney stacks include two yellow brick stacks to the original section, two rendered stacks to the return, and a brick stack to the housekeeper's quarters. Cast-iron rainwater goods are present throughout.

Northwest of the housekeeper's quarters stands a former dry closet (built between 1834 and 1858), now used as a shed. It is rubble-built with a Bangor blue slated gabled roof, a timber-sheeted doorway to the east gable, and a small window opening to the south façade.

To the south of Ballywilliam House is a drive with a gate screen comprising a low curving wall, simple gate pillars, and plain mid-19th-century wrought-iron gates. To the south and west of the house is a large collection of outbuildings, probably dating from the early to mid-1800s, with a large two-storey section to the southeast (along the west side of the entrance drive) in rubble and brick, dating from the later 19th century. Large portions of the outbuildings are currently undergoing conversion to offices.