Report on a historic building survey undertaken on a former agricultural outbuilding at The Grange farm in East Firsby, prior to its conversion to domestic accommodation. The surveyed building comprised a mid 18th century barn: an east-west aligned single storey, one bay building of finely coursed limestone rubble, under a pitched gabled pantile roof. There is evidence of a former granary or hay loft at its eastern side with a pitching hole in the north elevation. Large double doorway towards the east end of the north elevation with brick surround, and a single doorway opposite in the south elevation. Infilled slit vents at ground floor level in the south and east elevations. Internally, the barn has an unusual roof structure, comprising pairs of purlins supported by posts off trusses, with minor rafters supported by tie beams, all at regular intervals.