Cefnddwysarn Methodist Chapel was first built in 1822 in the Vernacular style under a single roof span with the adjoining chapel house. Both are built in stone with a slate roof. The south-eastern schoolroom elevation has a sash window with glazing bars each side of the centre doorway, which has two wooden-boarded doors. The chimney stack at the north-eastern end is made from brick.
The interior has painted plaster walls and ceiling. There are the remains of remains of a nineteenth century fireplace shelf and brackets. The panelled dado is possibly constructed from former chapel pews. The adjoining chapel house has two attic sash windows, above the ground-floor sash windows and two central wooden-boarded doors. Since the construction of its sucessor (NPRN: 8492), this chapel has served as a schoolroom and vestry.

RCAHMW, May 2011