Felin Cochwillan

3-storey, long rectangular building aligned roughly north-south with single-storey range projecting at right-angles to east at north end, and added lean-to (housing corn-drying kiln) against south gable. Roughly coursed rubblestone with voussoirs to segmental-headed ground-floor openings in long walls and slate lintels elsewhere, all windows with slate cills; slate roofs. Long walls in 5 symmetrical bays with main entrance on east side through central boarded double doors with glazed panels and rectangular overlight; gated boarded door with pulley for hoist directly above; to left are 2 horizontal sliding sashes on each floor, 12-paned on first floor, 16-paned to ground, with one identically detailed window on each floor to right. To right of these is the projecting gabled range with central boarded door and large 2-light window in angle with main range on south side; integral end stack with red brick shaft. Roof of main range has 3 small 2-light 8-paned gabled dormers with miniature king-post trusses to bracketed gables alternating with 2 triangular vents; rooflight and purple brick ridge stack with rendered base to left of right dormer. West wall has same window arrangement as east except where disrupted by water wheel to south, accounting for absence of window on ground floor of southern bay and presence of small 18-paned window in 2 lights immediately above wheel; 2 triangular vents in roofslope. Wheel is of undershot type with wooden spokes and iron-rimmed wooden paddles, fed by raised slate slab-lined water channel from mill race to south. 2-storey lean-to grain drying shed on south gable end. North gable end of main range has same windows as to long walls, 2 on ground and first floors, one to second floor; boarded door under bracketed lean-to hood on left of left ground-floor window.

House occupies northern bay and single storey wing only. Mill appears to retain all its machinery substantially intact, including 4 sets of stones. Well-preserved drying kiln in lean-to addition, with slate-slab construction square-section kiln, and perforated tiled drying floor above.