Iv'e had more info. The windows will need to be cleaned by hand off the cherry picker.
Why?
It's not been cleaned for years, the frames are not good quality, and a perfect finish is required.
On the large windows is is aprox 11m to the top of the windows.
So each window on the large section of the mill is about 3m tall, therefore each "PANE" is about 3' x 2' of which there are 12 in each window.