Pen Hesgyn-Isaf is a two-storey T-shaped house of limestone rubble construction with a pitched slate roof. The head of the T is a sixteenth century house, the long block being added in 1662. The seventeenth century block has been extensively modernised and a lean-to added on the western side. The sixteenth century block retains its original mullioned windows. The interior of the sixteenth century block includes an original four-centred Tudor-arched fireplace, ceiling beams, and paved flooring. Few original features survive in the seventeenth century block.

(Source: Site file AN/Domestic/SH57NE, also RCAHMW Inventory, 1937 [1960 reprint], p. 111)

J Hill, RCAHMW, 28 November 2003.