One of the oldest windmills in the UK is at risk of collapse, we are working to save it.

Bourn Windmill is located between the villages of Bourn and Caxton, just south of Cambourne. It was purchased by our charity in 1936 and restored from a state of dereliction into working order.

Watch the video below to learn more about the Bourn Windmill project with Graham, one of our Mill volunteers. 


The Windmill dates from before 1636. It is an open trestle post mill, which means that the whole mill rotates around a central pole. There are only around 50 of this type of extraordinary windmill remaining in the UK, 5 of which are in Cambridgeshire. Much of the mills' interior and workings are original with numerous names and dates carved onto the woodwork. In recognition of its heritage value to the nation, the windmill is designated as an Ancient Monument and is Grade I listed.

Graham Bruce is one of the CambridgePPF volunteers who helps to maintain the mill, “during a routine inspection in 2020 we found evidence of rot in the cross beams. It is the beams that help support the weight of the mill and so this was a bit of a concern, so the charity contacted Historic England for help. They provided advice and an emergency grant to pay for a structural engineer and Millwright to carry out investigative surveys.”

In June 2020, they started removing the bitumen that protects the woodwork in order to assess the extent of the rot. What they found surprised and concerned them, as Bill Griffith’s, the Millwright describes “a sand and cement type material, which we had imagined had been used only in a limited way as a filler for small defects, was actually extensively distributed in the centre of all four crosstree arms. The wood surrounding this sand and cement material showed rot in several places and it appeared that rainwater was infiltrating the structure of the crosstree arms". The mortar was used for repairs in the 1980s when rot was discovered. These repairs are now over 35 years old.

The conclusion was a risk that the beam could fail and the mill could collapse. It was considered that it was not safe enough to complete the investigative surveys, which triggered the start of the first major phase of this project.

Phase 1 Preventing collapse and designing repairs

The mill needed to be made safe by scaffolding/propping. Once this was done the surveys to assess the extent of the damage could be completed. It should then be possible to design a scheme of repairs in order to secure the future of the mill.

The mill was closed until further notice, and has been placed on the “Heritage at Risk Register” by Historic England.

We were delighted to be awarded an emergency grant of £23,250 by Historic England towards the £33,000 costs of the first phase of the project. The remaining £10,000 has been raised from members of the public through a fundraising appeal, as well as some small grants from South Cambridgeshire District Council, Bourn Parish Council, Paxton Parish Council and the Society for the Preservation of Ancient Buildings. The support has been amazing - thank you!

This funding has enabled us to tender and appoint an experienced project team, led by Tim Buxbaum. The sails of the mill have been removed (see video below) in order to lessen the weight on the supporting beams and to reduce the impact of the wind. Once this was done the scaffolding and propping was put in place. We were all relieved that this urgent work has been carried out because it means that the risk of the mill collapsing in a storm has been significantly reduced.

Despite some delays caused by the pandemic the project team has been able complete their investigations to understand the full extent of the damage and how to repair it.

The huge beams that support the mill are 140 years old and it is considered that they are beyond repair and will need to be replaced. The brick piers that they rest on also need repair (possibly replacement). We also need to repair a rotten window frame, stop a leak in the buck and we would like to renovate the sails before they are re-installed.

Phase 2 Repairing the mill and re-opening it

It is estimated that we need to raise around £16,000 from donations and supporters, on top of significant grant funding so that we can commission the repairs and re-open the mill. Fundraising is under way, please make a donation if you can, every little makes a difference (scroll down to make a donation).

Please continue to follow this page for updates and progress reports on the Save Bourn Windmill project.