Pen Llwyn Farmhouse is an early to mid-19th century, stone-built, 1 1/2-storey, double-pile plan farmhouse of two main units to front, with recessed flanking outer- units, formerly agricultural. The house has a symmetrical facade of 3-light mullion windows flanking a dressed stone central doorway. At first-floor there is a lower 2-light window over the doorway flanked by similar height 3-light mullion windows. The outer bays each have a 2-light mullion window only to ground-floor. The rear N-W elevation's openings have brick arches, consisting of a central doorway, flanked by windows with sliding sash frames to each floor.

The properties agricultural outer units have been incorporated into domestic accommodation, but old photos indicate the south-west end to have been a cart-house with external gable-end stone stair to granary over. The north-east end is shown as a stable with window opening to ground-floor and loft over.

Visited, Geoff Ward, at the request of Peter Jones-Hughes, Flints. conservation officer, 15/02/2006.