Mountnessing Windmill

Mountnessing Windmill is a roundhouse windmill constructed in 1807 for the Agnis family, who were both owners and millers. It was restored between 1979 and 1983. The windmill is built of red brick in a Flemish bond pattern, with a sheet metal roof over boarding. Parts of the structure are timber-framed and weatherboarded, also with a sheet metal roof. The roundhouse is 16-sided, with two 20th-century boarded doors, and a conical roof. The buck, which supports the sails, has a slight bay on the weather face. There are two 20th-century fixed windows on each side, and two more at the rear of the structure. A tailpole and steps lead to another boarded door at the rear. The interior roof is barrel vaulted. Four single-shuttered spring sails are present. The windmill is situated on a mound.

The original cross-trees, quarter bars, and post are mounted on stepped brick piers; the western pier has been repaired, and all packing pieces have been renewed, with bolted splints on three quarter bar and cross-tree ends. The original tailpole and large timbers to the steps remain, though the treads have been replaced. The buck was rebuilt between 1979 and 1983 by Vincent Pargeter, a staff millwright for Essex County Council, retaining original timbers including the crown-tree, side girts, weather beam, spindle beam, tail beam, two sills, and other lesser timbers. A rolled steel joist has been added internally to reinforce the left side girt. The mill contains two pairs of under-driven head stones made from French burr, with one runner removed for demonstration purposes. A cast-iron windshaft, originally from a working mill, is present but likely was second-hand when initially installed. The barrel wheel and wallower have been rebuilt, incorporating parts of the original components. All internal fittings and machinery were constructed after 1979 by Peter Stenning of Kent and Richard Seago of Norfolk, with some original bin framing retained and reused. Graffiti are visible on the post, including depictions of windmills and inscriptions dating to 1821 and 1827. The date 1807 is painted on the crown-tree.

Historically, the mill was owned and operated by the Agnis family from 1807 until 1924, with a brief period of operation from 1932 to 1933. It was acquired by Mountnessing Parish Council in 1956 and subsequently by Essex County Council. It was the second windmill in Essex to be restored to working order, following Aythorpe Roding.