Walled Garden, Mainhill House

This is a mid-19th century, three-bay, two-storey symmetrical farmhouse with single-storey wings extending on either side. The house is constructed of coursed, droved cream sandstone with ashlar dressings, while the sides and rear are of squared, snecked red sandstone rubble. It features canted bays on the ground floor, a band course above the first floor and at the eaves, and a symmetrical south facing (principal) elevation with slightly recessed, piended wings. Flat-roofed canted bays are present at ground floor level, topped by a shallow parapet, and there's a central bracketed tablet at eaves level. The east elevation has irregular fenestration, with one window in the main block and two in the ground floor wing. The north elevation features regular, but irregular in size, window placements, with one blocked window on the ground floor. Two windows are visible on the west wing. The west elevation displays a side entrance and a single window to the single-storey wing.

A central, six-panelled timber doorway is set in a raised surround, with a letterbox fanlight featuring margin glazing. A boarded side door also has a margin-paned letterbox fanlight. Windows throughout are eight-pane sash and case, with square-pane or lying-pane glazing. The roofs are piended and covered in blue slate with modern flashing. There are two prominent brick-rebuilt wallhead chimneys at each end wall, topped with clay cans.

Internally, the rooms have timber shutters and linings with fan detailing above the windows. The main reception rooms feature decorative foliated cornices. A staircase has cast iron balusters, while the cross-corridor arches and entrance hall are supported by lion-head and acanthus corbels. A stone floor is found in the service corridor.

To the west of the house is a small, single-pitch outhouse, possibly a kennel, built of squared rubble sandstone with a modern corrugated iron roof and boarded timber door.

A surviving west range of farm buildings consists of cartsheds with a granary above. This building is of squared snecked rubble construction with high-level windows on all sides, and a blue slate roof. The eastern side features cart arches with polychrome brick segmental arches and chamfered pillars. A gabled granary door is positioned above the central arch. A short projection remains from a demolished north range.

A three-walled garden is enclosed to the south by a burn and is bounded by walls constructed of squared rubble with triangular capstones.