Heritage Consultancy


Upminster Windmill Restoration 2016-19

One of the most comprehensive repair projects ever undertaken to a smock windmill in the UK.

Built in 1803, Upminster Windmill is one of England's largest and most powerful smock mills. It is listed Grade II* and is owned by the London Borough of Havering. The mill is managed by the Friends of Upminster Windmill who, in partnership with the Council, were successful in obtaining grant aid from the Heritage Lottery Fund and the Veolia Thames Trust to fully restore the windmill to working order and to build a brand new visitor centre alongside it.

Bonwick HC specified the conservation and repair works to the mill's timber frame, its brick base and the mechanical elements from sails to millstones and auxiliary machinery. We are co-managing the repair project which is being administered by Rees Bolter Architects. 

The repair works are being undertaken by a Dutch millwrighting firm, Bouw Molens & Techniek Bertus Dijkstra. Its proprietor, Willem Dijkstra, is a millwright and engineer with experience in conserving a wide range of heritage structures from church spires to mechanical wind engines for land drainage. Willem has recently restored another English-style windmill which was exported to Jerusalem in the mid-19th century by millwrights from Kent. 

The cap roof of Upminster Mill, its sails and upper gearing have made their way through the channel tunnel to Bertus Dijkstra's workshops in Sloten, Friesland. These will gradually be re-assembled on site during the latter part of 2018. The project is due to be completed in 2019 and the mill will officially re-open in 2020.


The internal machinery of Upminster Mill is mainly constructed of timber. It represents the 'wooden engineering' of the early 19th century, before the widespread adoption of cast iron gearing and mechanical parts.