20 years ago I extended our house and installed softwood sash windows. Each sash is 750mm x 660mm x 42mm and has 6 separate lights/double glazing units (about 6mm gap). They have spiral spring, not rope and weights. Some of the glazing units have failed and beginning to mist and also the gazing bars are wide so they don’t have the look of a traditional Georgian sash. The timber is in excellent condition and no sign of rot.
I need to replace some of the glazing units and have wondered if a better solution would be to take out all 6 and replace with one double glazed unit with surface mounted bars. Within the frame I could have a larger gap in the double glazing. I would need to work out the best way of fitting the single unit as there are no rebates on the frame.
I would be grateful if any advice on whether this is a good idea?
Thanks in advance.