Barn and Adjoining Horse Mill Approximately 50 Metres North of Haldenby Grange Farmhouse

This is a threshing barn and adjoining horse mill, located approximately 50 metres north of Haldenby Grange Farmhouse. The building is constructed from red-brown brick and features a roof made of pantiles and Yorkshire stone slate. It has a rectangular shape with a through wagon entrance and a projecting canted horse mill on the south side. The structure stands two storeys high and is about 20 metres long.

On the south side, the wagon entrance is positioned to the right of the centre, featuring a timber lintel and a recessed segmental-arched brick panel above. To the right of the entrance, there are three tiers of three breather slits. To the left, there are also three tiers of similar breather slits, with four slits at the lower level and a board door beneath a segmental arch at the far left. The central and upper tiers each have five slits. The horse mill has a low brick wall and piers at the front, with brick piers on the sides, a hipped roof, and main beams visible inside. The eaves feature a single oversailing course of stone slate, and there are shaped kneelers.

On the north side, there is a lower wagon entrance with a 20th-century sliding door beneath a lintel. This side also has three tiers of closely spaced breather slits, with the bottom and central tiers each containing three slits to the left of the entrance and nine to the right. The upper tier has a slatted wooden ventilator for a pitching hatch, with nine slits to the left and three to the right. The west gable end has a central blocked door flanked by four breathers, with two tiers above, each containing five slits. The gable features tiers of four, three, and two slits, all of which are blocked. The east gable end has breathers and a blocked gable hatch. At the time of the last survey, the horse mill was derelict, and the barn was partly derelict. The interior has not been inspected.