The stable/Court-house at Trostrey Court, Usk is probably the original gatehouse, later converted to ox-house/stable. There is a 1667 date inscription (but it is not clear whether this refers to date of construction or the date of repair). It is built of rubble, of 2 storeys with an external stone stair.

This building has been described by Fox & Raglan as an Ox-house and others have suggested it is a gate-house, the removal of ivy reveals its blocked openings, but its original usage is uncertain.

It is possible that by 1667 Trostrey Court's meetings took place here on the first-floor at certain times of the year, and that the ground-floor was used as a superior stable for the horses of those attending the meeting. It would certainly have provided an impressive approach building alongside the house.

There appear to be three periods in this stone-built, rectangular, 2-storey building, although very little, except the walls survive from the first period. The straight-joint evidence of opposed doorways, perhaps indicating, it was originally, either a barn or a gate-house.
The second period relates to the 1667 date-stone on the gable over the external stair, a time when the whole building was rearranged, probably as a court-house over stabling. By the early 19th century the building had become a two bay cow-house, divided from a stable at the north-west end with granary/store over.

Geoff Ward, visited, 24/02/2006.