A grant to build a Mission Church at Hirwaun was approved in 1889. A Mission Room appears on the local Ordnance Survey second-edition 25-inch plan of 1901 (absent from the first edition of 1883-5). It was a rectangular building located on the north edge of the town. It is present on the fourth-edition six-inch map of 1938 but absent from modern mapping. It was probably demolished in about 1950.
Sources:
churchplansonline.org
OS mapping: 25-inch sheet Glamorgan XI.5; six-inch Glam.11NW.
http://www.hirwaunhistorical.org.uk/hirwaun-timeline.html

David Leighton, RCAHMW, 22 December 2014