St Osyth's Priory, Tithe Barn adjoining the west range of Gatehouse

St Osyth's Priory, Tithe Barn adjoining the west range of Gatehouse

This is a barn dating from the later 16th century, with three eastern bays converted to residential use in the mid-20th century. The north and west walls are constructed of septaria and limestone with flint galleted mortar and limestone quoins. The south wall is timber framed and weather boarded. The roofs are covered in red plain tiles, and the floors are partly brick and partly concrete.

The barn comprises 14 bays. The three eastern bays have been converted into a dwelling, and the south elevation features three porches with additional lean-to structures attached.

On the north elevation, there is a chamfered plinth and a band running at roughly two-thirds of the wall's full height. The stonework contains randomly distributed squares of limestone, echoing the chequered work of Lord Darcy's buildings. An 18th-century stable is attached to the west end at a right-angle. Immediately to its east is a double-width opening under a brick arch. Three other doors have chamfered limestone surrounds with Tudor arches and label-moulds. At the east end are three windows: two to the first floor of the converted bays and one to the ground floor. The west gable displays stonework patterning similar to the north elevation.

The south elevation features, at its west end, an inserted opening with double doors, above which is an inserted domestic window. In the fourth bay is the first of three wagon porches, with its entrance now boarded over. Lean-to structures are attached to the barn both east and west of this porch, which has a pitched roof. The central porch in the seventh bay retains its full-height wide opening, with knee braces from outer posts to the tie beam, though the doors are missing. The opening of the east porch in the eleventh bay has been reduced in height by weatherboarding, and a lean-to structure stands against the barn on its west side. To the east of this porch is the house conversion, with painted brickwork to the ground floor and weatherboarding above. The first floor has modern Georgian-style windows, while the ground floor has iron-framed casements.

Internally, the barn's fourteen bays are defined by posts braced to tie beams. On the north side, not all posts survive; only two stand to full height within the eleven open bays, the remainder missing the lower portion with only the braced section remaining. The posts to the south are slightly jowled, while those to the north are not, except for the first two posts to the west. The rafters are coupled, with principals supporting collars positioned below the upper of two purlins. The principals also carry short, straight wind braces to either side. Between each pair of principals are four common rafters running behind the purlins. The south wall consists of studs and a mid rail. Most of the sill beam survives, resting on a brick plinth.

At the west end, a partition with a platform above separates the three end bays from the main barn body. The platform creates an upper floor or loft, with access between this and the 18th-century stable to the north. A brick fireplace is located in the west wall at the south end of the platform. The eleventh bay to the east is also divided from the rest of the barn by a timber partition. Opposite each of the three wagon porches, in the north wall, is a smaller door set within a splayed opening under a brick arch. Both sides of the central porch have studs and a mid rail; the roof has coupled rafters with collars clasping a single purlin to each side.

Within the three converted eastern bays, few structural details are exposed. Visible elements include the severed upper section of the north wall posts braced to tie beams and some studwork.