I am hoping to fit a new window to what is to become a utility room. the boiler (a 16 yr. old Saunier Duval combi) is situated in the RH. corner of the far wall. The room has just been partitioned off & has no window & is therefore very dark. There is 2.4 metres of wall between the LH. corner of the room & the boiler. I wish to put in a high level window which will be at a similar height to the flue. What is the minimum distance allowed between the start of the window & the flue? so that I know how wide a window I am allowed to fit.