Former Laundry and Servant's Hall at Plas Gwyn

The Former Laundry and Servant's Hall at Plas Gwyn is a 2-storey linear building with rendered walls and a hipped slate roof, featuring slender rectangular rendered ridge stacks with capping. The main front faces the yard behind the house. The former laundry is located at the left (south) end of the building and includes a tall paired-sash window with 42 panes, along with two similar windows on the rear side. To the right, there is a doorway with a slate plaque above it that reads: Dean John Jones / 1650 - 1727 / Addysgwr a dyn garw, which commemorates the father of William Jones, for whom the current house was built.

The former servant's hall is to the right and consists of a 2-window range with 12-pane horned sash windows on each floor. On the rear, there is a small 6-paned sash window located between the stack and to the left of the left-hand stack are tall paned sash windows on both the first and ground floors, with a similar window also found in the north gable.

The interior of the former servant's hall was not inspected during the survey but has been modernised and converted into a flat for the housekeeper. The former laundry still retains the original copper and some of the drying apparatus.