12 Mawddwy Terrace

12 Mawddwy Terrace is part of a terrace of eight workers' cottages located in Minllyn, Dinas Mawddwy. Built in the mountain-Gothic style, the cottages are constructed with selected local slate laid on bed and feature slate roofs. The design includes two bilaterally symmetrical cottages that form a large gable at each end, which are set slightly forward to dominate the central cottages. Each cottage has a 4-paned half-glazed door with a plain overlight, and 4-paned horned sash windows on both floors, all topped with triangular heads made of shale voussoirs. The upper floor windows in the central cottages are set within five large raised gabled dormers. The cottages have deep eaves supported by extended purlins and ridges with shaped ends. Stone stacks are present on the party walls, featuring necking strings and outsetting heads. The large gable ends showcase decorative timber framing in the upper half. Internally, the partitions are said to be made of slate slabs set on end, an innovation attributed to Buckley and his architect James Stephens. While the cottage has a 20th-century replacement door, it retains its original windows.