Yes, finally my kitchen window has been sorted out and I`ve a brand new window. A full pane of glass to see out of, without the monstrosity of a big square white fan in the the top quarter of it. The kitchen is so much lighter and brighter now.
All, I have to do now is wait for the bill ! - but the chaps (and they are ones I trust) tell me that the cost of the window will be cheaper than the cost of a new fan in it would have been. That sounds amazing to me.