I have a house 1968 currently on wood joinery simple glazing with internal glazing. Would there be a gain by replacing the glazing and glazing by double glazing 4/16/4 on same carpentry (thickness of the carpentry 32 mm).
The cost of such a modification (replace glazing and glazing by double-glazed cassettes) would be very important. Moreover, the thickness of 32 mm seems a little too fair to implement a 4/16/4 double glazing, the overhang would be too small, the addition of rods in over-thickness would be necessary and the weight would be increased: too many constraints!
I think it would be better to replace your joinery outright, for example by a PVC product that would insure you a better insulation for a cost lower than the solution that you envisaged.
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