St John's Church Hall, a Grade II listed building, was erected in 1910. It was built at the expense of Mrs Williams, Plas Mynach (formerly Mrs Perrin), patroness of St John's Church (NPRN 43878).

The single storey hall, in the style of Douglas and Fordham, is constructed of snecked dressed slate stone with red sandstone dresings and a slate foor. It is built in vernacular Tudorbethan style. The building is rectilinear in shape, a projection at its east end. There is also a plain tapered and banded chimney at the east end. The west gable is crow-stepped, with a ten-light mullioned and transomed window with a wide segmental relieving arch above. There is a gabled porch entrance in the south elevation, with butresses to the left and right. The central entrance and has modern boarded doors with flanking mullioned windows (two-2-light to the left and three-light to the right). Above is a plaque with a heraldic device and lettering, which reads 'Church Hall, Anno Christi MCMX.' It has a simple slate-hung louvre with feathered eaves and a lead ball finial. The interior is divided into four bays, which are divided by butresses. The two central bays are step-gabled and have six-light windows. the flanking bays are lower and ungabled, with four-light windows. There is a large stage at the east end. Throughout the interior are contemporary 9-panelled doors, along with simple Art Nouveau doorcases and door furniture. There is a boarded dado with a moulded rail.

Sources include:
Cadw, Listed Buildings Database

N Vousden, RCAHMW, 23 July 2012