Plas Llidiardau

Plas Llidiardau is a two-storey country house built in 1854, constructed of coursed rubble stone with tooled cornerstones and red brick window dressings. The building is topped with steep slate roofs and stone chimneys.

All windows are long moulded timber-mullioned with narrow sashes featuring horizontal glazing bars, set within red brick cambered-headed surrounds with flush slate sills. The architecture is of simple detail throughout.

The asymmetrical south-west garden front comprises three bays. The centre features a long two-light stair light serving the first floor. To the left is a slightly projected narrow gable with twentieth-century bargeboards, containing a first-floor two-light window and a ground floor four-light window (altered in the twentieth century with a French window inserted in the centre two lights). To the right stands a large canted-sided projection with a five-sided steep hipped roof and three two-light windows on each floor. End wall chimneys feature external chimneybreasts with plain rubble stone square shafts. The rear wing running north-east has a rebuilt stone ridge stack.

The north-east front has two bays. The left bay is recessed and features a broad cambered brick arch over a herringbone-boarded door with side-lights and a two-light window above. To the right is a slightly projected gable containing a two-light window over a large three-light window. The rear north-west gable end displays a two-light window over a three-light window. Recessed to the right is a narrow bay with a hipped roof, containing a single-light window on each floor to the left and a back door to the right in the angle to the south-west rear service wing.

The service wing has a stone rebuilt ridge stack and formerly terminated in a crosswing, which was removed in the later twentieth century. The north-east front features a timber gallery across the first floor, originally providing access to the cross-wing. The gallery has four nineteenth-century brackets on corbels, though the boarding and glazing are twentieth-century (a historic photograph shows it originally had more ornate mock half-timbering). Two ground floor two-light windows are present below the gallery. The gable end has twentieth-century render where the crosswing was removed. The south-west side of the service wing has paired doors to the left, then a ground floor single-light and two-light windows with two two-lights above (not aligned), followed by a long narrow stair light to the service stair, then a two-light on each floor (not aligned). The rear return of the front range has an inserted twentieth-century ground floor window in similar style.

The entrance hall leads into a stair hall on the left, with principal rooms on each side of the stair hall. Original doorcases are chamfered and stopped, with side planks finished in curved pointed tops. Six-panelled doors, panelled window reveals and panelled shutters are present throughout. The centre stair hall contains an open-well stair with heavy roll-moulded rails, closed strings, octagonal newels with moulded finials and pendants, and octagonal balusters. The south-west room has been altered in the twentieth century as a kitchen. The north-east room, with a canted bay, contains a plain black marble fireplace and a moulded cornice. Back stairs have a chamfered newel and finial. The rear wing contains a former kitchen and butler's pantry.

The first floor landing features a big rectangular frame to an opening to the rear landing. The main landing has two doors leading to bedrooms: the front left bedroom has a plain slate fireplace, and the front right bedroom has a marble fireplace with roundels. The rear landing has four doors off. The north-west bedroom has a grey marble fireplace moved from the ground floor south-west room. In the servants' corridor are two remnants from the previous house: a cupboard with six-panel fielded-panelled doors featuring some ogee-headed panels (dating to the earlier to mid-eighteenth century) and a curved twelve-pane sash window with original very thin glass panes (late eighteenth to early nineteenth century).

Basement cellars are present beneath the building.