Capel Blaenplwyf including attached vestry and house range to rear

The building is a chapel dating from the 1878, constructed of coursed brown rubble stone with dressings in blue/black and yellow brick. It has a slate roof with overhanging verges, plain bargeboards, and a timber finial. The front gable features a central large recess flanked by two narrower recesses, all with triangular heads defined by four plain piers. The piers have black brick quoins and yellow brick at eaves level; the triangular heads of the outer windows are detailed with moulded yellow brick, black brick voussoirs, and a yellow brick apex diamond. The central recess mirrors this detailing, extending upwards to the springing of a similar triangular head. A shallow gabled porch with bargeboards and a yellow brick cambered-headed doorway sits at ground level. Double three-panel doors are set within the porch, above a plain overlight and a plaque reading 'Blaenplwyf M.C.'. Above the porch is a row of three arched windows in yellow brick, each with a moulded brick conjoined hood and stepped over keystones. The outer bays have similar long windows with hoods divided by a panelled stone lintel between floors. Foundation stones, dated August 16th 1878, are visible below each window. The glazing includes marginal bars and coloured glass in the margins. Above the central triplet of windows is a yellow brick roundel with a moulded arched yellow brick hood and an eight-pointed louvred vent within. The north side wall has a pier corresponding with the facade, and four tall arched windows in yellow brick surrounds. The south side is rendered except for the corner pier, eaves, and plinth. Three windows are visible, the fourth bay being obscured by a chapel house set at a right angle. A narrow, two-window, two-storey front, with twentieth-century plastic glazing and a door, faces onto the south side. A brick chimney stack is located on the left end of this section. The house is the south end of a lean-to vestry range extending across the rear of the chapel, which is rendered with a half-hipped north end. A boarded door within a yellow brick surround is visible in the chapel gable above the vestry.

Inside, a single gallery runs along the entrance end, featuring long horizontal panels and roundels above a bracket cornice, supported by two iron columns. The ceiling is coved, forming four bays with timber ribs on corbels. There are four panels with moulded surrounds and plaster roses. The chapel contains numbered pitch-pine pews arranged in three blocks, with shaped bench ends. The set fawr (pulpit area) has curved corners with open balustrades and ball finials to the newels. The ornate pulpit includes short stairs up each side, turned balusters, ramped rails, turned newels, and heavy bosses at the joint between the rails and the pulpit frame, topped with ball finials. The pulpit platform has contrasted coloured woodwork, short balustrading each side, and panelling below. The pulpit itself breaks forward with canted panelled sides and an ornate panel front in contrasted colours, featuring heavy carved consoles, a carved cornice, and a bookrest. Panelling behind the pulpit forms the lower portion of a tall, stucco pedimented Corinthian aedicule that frames an arch with a keystone, pilasters, and moulded capitals. Doors lead to the vestry on either side of the pulpit. A lobby features two half-glazed doors and a central window with etched and coloured glass.