The site is depicted on three editions of the historic 25-inch O. S. maps as 'House of Mercy', but it was formerly a fulling mill, with an early to mid-nineteenth century miller's house forming the south-eastern part. This is built of random rubble with block quoins and a pitched slate roof, and has a Georgian-style front to the south-east, with a central door with fanlight above, and flanking 16-pane sash windows.

The fulling mill was supplied with water by a leat taken from a weir across the River Taff at ST 15237842, still extant, which supplied also Llandaff corn mill (NPRN 403395). The 1st edition map (1880) shows the leat passing round the buildings on their south side, with a weir to the west diverting water underneath the buildings, evidencing that the mill was behind the house to the north-west. By 1901 this channel under the buildings has gone, and the second and third editions (1901 and 1920) show the buildings divided into three cottages, which was still the case when they were Listed in 1987. The buildings were considered to be of particular interest as a scarce example of a surviving fulling-mill within the city boundary. Since then they have been reconverted and modernised as a single dwelling.

Information from Cadw Listed Buildings database.
W J Crompton, RCAHMW, 9 October 2014.