1.17th - 18th century exterior. Once 12th century refectory? 2 storey and attics. Gabled rear wing with tall square rubble stacks.

2. Present house of probably early 16th centuy origin with a 17th century addition at the east end. The house was altered, refurbished and extended at the rear in c1840 and externally has been little changed since. Historically owned by the Stradling family of St. Donat's Castle.

'Outwardly Plymouth House has the appearance of a late C17 house in the early Renaissance style as indicated by the central gable. However, a few details - early windows in the W gable and the formerly arch-braced roof - indicate that it is older. It has some affinity in plan with the previous lateral chimney houses, but drastic reconstruction including the transfer of some fireplaces from the front to the back, make the original layout uncertain. The W half of the range is substantially a house of the late C15 or early C16 century which was subsequently extended but the removal of its E gable end makes its full extent uncertain.' (RCAHMW)

Constructed to two storeys of rendered walls, presumably over local limestone rubble, with Welsh slate gabled roof with old slates on the rear pitch. Two pairs of old tall square stone stacks with capping to rear pitch; formerly a lateral stack to front elevation with blocked-in windows beside it.

Five bay front or south elevation has modern transomed and mullioned 2-light wood casements. The left hand wing of the building, which is 17th century, is disused and has blocked windows. Central bay in front elevation has 19th century fretted bargeboarded gable and part finial, and a later slate roofed lean-to porch with wide boarded door. Steeply pitched roof with stone verges, gable stacks at either end. The West gable end has plaster cladding to stone wall. Above a lean-to are early window openings with dripstones and a chamfered rounded headed window to the attic storey. East gable has a window to each floor.
Rear elevation with damaged later rear wing, otherwise obscured.

'In two of the roof trusses the extended feet of the principals are curved, while the cambered collar has, on its soffit, the mortices and peg-holes for former arch-braces with corresponding holes and seating on the principals; the two through-purlins on each side have been renewed, but reused material in the roof includes a chamfered purlin with indications of intermediate pegged rafters or narrower bays than at present. Other trusses have lap-jointed collars with notched ends pegged to the principals.' (RCAHMW)
(Source: NMR site file, Cadw listing description) S Fielding RCAHMW 01/12/2005