| Upper Dyffryn House | |
| Type: | House |
| Map Relief: | yes |
| Coordinates: | 51.9062°N -2.8418°W |
| Location: | Grosmont Monmouthshire |
| Built: | 1692 |
| Architecture: | Vernacular |
| Governing Body: | Privately owned |
| Designation1: | Grade II* listed building |
| Designation1 Offname: | Upper Dyffryn House |
| Designation1 Date: | 6 May 1952 |
| Designation1 Number: | 1922 |
| Designation2: | Grade II* listed building |
| Designation2 Offname: | Former Detached Kitchen and Dairy at Upper Dyffryn |
| Designation2 Date: | 19 October 2000 |
| Designation2 Number: | 24150 |
Upper Dyffryn House, Grosmont, Monmouthshire is a farmhouse dating from the early 17th century. It was built by John Gainsford, Sheriff of Monmouthshire in 1604. The farmhouse is Grade II* listed as are the dairy and kitchen which stand a little way from the main building.
The farmhouse was constructed in the very early 17th century, Cadw recording that the builder was almost certainly John Gainsford, who served as Sheriff in 1604. Both the exterior and the interior have been little altered subsequently. The kitchen and dairy, which comprise a separate building set a little away from the house may originally have been constructed as an independent dwelling. Its construction date is "probably contemporary" or slightly later than the farmhouse.
The architectural historian John Newman describes Upper Dyffryn as a "tall early 17th century farmhouse". It is two storeys high, with attics above, and constructed of Old Red Sandstone rubble. It has a stair turret and tall chimney stacks, representing "a considerable advance in layout". The dairy is also of two storeys and of rubble construction and has a "fine ovolo moulded doorway with ornate shaped door-head".
Both the farmhouse and the dairy remain in private ownership and have separate Grade II* listed building designations.
. John Newman (architectural historian). The Buildings of Wales. Gwent/Monmouthshire. 2000. Penguin. London. 0-14-071053-1.