Various farm buildings were built on Lundy by Sir John Borlase Warren in the 1770s, and a barn was mentioned in the letters written by the Irish steward, Mr Mannix, to Sir Aubrey de Vere Hunt in the 1820s.
A barn is marked, too, on a map of 1820, in roughly the same position as the present one. It is curious, therefore, that it does not seem to appear, or at least not in the right place, in Mary Ann Heaven’s drawing of the village in 1838. It may be that the 18th century barn became ruinous and was rebuilt by Mr Heaven after 1838. His agent, Mr Malbon, does in fact refer to a new barn in 1839. The present Barn is constructed of granite and was converted to a threshing house when the round house was added. This provided a circular walk for a horse or donkey, harnessed to a gin to provide motive-power for the machinery in the adjacent threshing room. Later when engines replaced animal and man-power, the Barn housed one of the few mechanical contrivances on the island: the ancient 4½ horsepower Blackstone stationary engine. It ran on paraffin and powered the threshing box, chaff-cutter, grist-mill, circular saw and subsequently a sheep-shearing machine for which purpose it never really had sufficient speed.
On October 4th 1944 Lundy suffered a violent gale and the roof of the Barn was lifted off in one piece, falling near the entrance to the stables and the dung heap