Plas Penrhyn

Plas Penrhyn is a Regency country house with origins dating back to the sub-medieval period. It is two storeys high and built of stuccoed rubble, arranged around a double-pile plan, with the east wing being the primary section. The building has slate roofs and end chimneys.

The main west-facing elevation features 16-pane sash windows, three on the first floor and two on the ground floor. A prominent, full-length Regency verandah extends around the sides, topped with a hipped slate roof and supported by flat, pierced wrought ironwork made at the Porthmadog foundry. A slate-flagged terrace sits in front of the verandah. The entrance is on the north return, through a part-glazed door with a good Georgian fanlight above, all within the returned verandah. To the right of the entrance is a 12-pane sash window, paired with a 16-pane sash window on the first floor, and a blind window to its right. The south return is asymmetrical, with 12- and 16-pane sash windows on both floors. The primary eastern range has a near-central entrance to the three-bay east elevation, leading to a simple, single-storey porch with 16-pane sashes. A further entrance is located to the far right, with a 12-pane sash window above and a flush lean-to extension beyond.

The Regency block contains an entrance hall featuring a late Victorian geometric tiled floor in buff, brown, red, white, and black. A depressed arch separates the entrance hall from the stairwell to the rear, which now has a modern stick-baluster staircase, replacing a lift installed around 1960. It is believed that the original main staircase was in this location. Drawing and dining rooms are situated to the right of the entrance hall, with the dining room located at the rear. Both rooms have six-panel doors with panelled reveals and convex panelled Regency architraves, showcasing applied foliated corner bosses, panelled window reveals, shutters, and moulded marginal ceiling plaster. The dining room retains its original wooden Regency chimneypiece, mirroring the architrave design with an added cable moulding. The drawing room has a simpler wooden fireplace with engaged colonnettes.

The primary range includes a stick-baluster staircase with a mahogany swept rail and columnar balusters, as well as a returned, balustraded first-floor landing. The former hall, now a kitchen, has a large inglenook fireplace with a segmental bresummer and early 19th-century mantelshelf. A boarded door is accompanied by contemporary boarded cupboards above. Above the kitchen door is an early hanging larder with turned sides and door, leading to a plank porch with a boarded door and access to a cellar via a flight of old slate steps. The ceiling is beamed, featuring plain lateral ceiling beams and joists.