Cnoc an Dudain, 7b Ruisgarry, Berneray

7b Ruisgarry is a single-storey, roughly rectangular-plan cottage built from rubble, likely dating from the late 18th or early 19th century. It features a thatched roof and thick, battered rubble stone walls with slab-capped wallheads. The window openings are small and deeply recessed. The cottage is located on the north side of Bays Loch on the east side of the Isle of Berneray, near the west edge of Loch Watersee.

The front elevation, facing northwest, is four bays wide, with an entrance positioned to the left of center. The rear elevation, facing southeast, has two window openings, and there is one window on the northeast elevation.

The building has replacement side-sliding timber sash windows and a timber ledge and braced front door. The piended roof was reinstated around 2010 and is thatched with marram grass, featuring a continuous marram ridge. The roof is entirely netted and weighted along the eaves with stones, secured to the netting by wire. There is one stone chimneystack with a plain circular pot. Timber boards have been used above some of the window and door openings to help secure the thatch.

The interior of the cottage was seen in 2017, revealing that the internal fabric and layout are all from the 21st century. The interior roof has exposed timber rafters and timber boards.