Walled Garden, Hallydown House

Hallydown House is a largely Later 18th century house, with subsequent additions and alterations. It is a symmetrical, two-storey building with a basement, originally designed with three bays, and displaying classical architectural detailing. A single-story wing at the rear creates a near-L-shaped layout. The main walls are predominantly whitewashed harl, with whitewashed, coursed render on the northeast side, and sandstone ashlar dressings, some of which have been painted. A horizontal lintel course runs along the basement level, and the eaves feature modillion cornices. Rusticated quoins are present on the front of the house, being flush at the basement and rear, while the ground floor front windows have architraved surrounds and the remaining windows have plain margins. The windows are relatively squat, positioned at both basement and first floor levels, and generally feature projecting cills. A near square-plan walled garden is located to the southwest of the main house.

The northwest (entrance) elevation features a projecting perron stair, which overhangs the basement. The stair has stone treads, foliate wrought-iron uprights, and iron handrails. A timber-panelled door, centrally positioned at ground floor level, is accessed by the stair, and is topped with a radial fanlight within an architraved surround with a consoled cornice. Single basement windows are located on either side of the central stair, with larger, corniced windows aligned at ground floor level, and single windows at the first floor.

The northeast side elevation displays a two-bay gable end on the right, with a single window at basement level and a painted imitation window above. To the left, a single-story wing recessed and containing a boarded timber door and a single window. The southeast (rear) elevation features a large, round-arched stair window at the centre, and single windows at all floors to the right (with a blocked opening at ground floor). A single-story addition projects to the left, and a modern conservatory is recessed to the outer left. The southwest side elevation incorporates a modern conservatory projecting at the centre, a single window offset to the left at ground floor, and a single-story addition attached to the outer right.

The windows are timber sash and case with 6 or 12 panes of glass. First-floor windows are 6-pane tilting windows, and the stair window at the rear has stained border-glazing. The roof is covered with grey slate, and has stone-coped skews. Painted brick-built apex stacks are present along with various ventilation cans.

The interior of the house was not inspected in 1999.

The walled garden, approximately 900 square meters in area, is situated to the west of the house, extending from the southeast corner. It is enclosed by rubble walls with a rubbled coping, and features a square-headed pedestrian entrance to the northeast with an iron gate. Partially enclosing the site are coped rubble boundary walls.