4 Rhiw Fach Terrace

4 Rhiw Fach Terrace is part of a row of houses located in Cwm Penmachno, constructed from squared dark stone rubble with alternating buff stone in the quoins. The buildings feature slate roofs and rectangular stone chimneys with water tabling, each originally having four flues. The ground floor windows and doors are topped with deep stone lintels.

Houses numbered 1 to 3 and 8 to 10 are designed as two-window homes, with upper windows positioned at the eaves and ground floor windows and doors aligned below. The doors are located to the right, except for No. 1, which has its door on the left. No. 1 has been extended at the rear with flat slate rubble, resulting in higher eaves and ridge. It also features a window on each floor on the southwest return. No. 10 has a basement due to the slope down to the stream, with a door and two windows to the right on the northeast return. Houses numbered 4 to 7 are double fronted, each with three first-floor windows and a central doorway flanked by windows. Nos. 4 and 5 have decorative render around their windows and doors, while No. 6 is fully rendered and painted. Nos. 1 to 7 retain 19th-century sash glazing, most with intact marginal glazing bars, whereas Nos. 8 and 10 have replacement glazing.

At the rear, there are various extensions, including a notable contemporary attached parallel gabled block to Nos. 3 and 4. The rear sections largely maintain small pane glazing, either horned sashes or fixed panes.

The houses are set in forecourts enclosed by low slate rubble walls, some featuring iron railings, with slate gate-posts. The partition walls of the forecourts are primarily made of upright slate slabs. Across the lane from the front of the houses, there are small gardens on land sloping down to the stream, with walls constructed from upright slate slabs.