Penlan including attached cottage formerly known as Dwyfor.

Penlan, formerly known as Dwyfor, is a substantial house built in the early 19th century, reflecting the Georgian architectural tradition. The structure features coursed rubble masonry, with the main facade showcasing coursed blockwork, large stones used as quoins, and lintels. It has a slate roof with deep overhanging eaves.

On the left side (north), the house is a two-storey, three-window range that includes a central doorway and 16-paned hornless sash windows with slate sills. The roof is adorned with rectangular stone gable stacks that have dripstones and capping.

To the right (south) is a two-storey wing that features a full-height bow on the left, which has French windows beneath a first-floor two-light casement window with a moulded label. The right side has a gabled front with two sash windows, where the first-floor windows are unequal in size. A slate-roofed verandah supported by timber piers runs across the front of the building. The entrance to the right-hand range is through a panelled door located on the left side of the south wall, with a window to the right. Above, there are windows set under the eaves, featuring moulded labels; to the right is an unequal sash window, and to the left is a blocked window.

The interior was not inspected during the survey conducted in June and July 2003.