I have a single storey extension which projects from the rear wall to one end of a 2 storey house at 90 degrees to the main house. The extension has a flat roof which I am considering replacing with a tiled pitched type. I am looking to re-work this room with new windows, a bit of brickwork etc. There is a first floor window above this extension, roughly where the apex of a pitched roof would meet the main building. Are there rules about distance between, for instance, the sill of the window and the top of the roof apex?
TIA
Phil