Just thinking about it,couldnt find any old posts or websites. But Say you cut a pane of glass made a 1/2inch plastic spacer glue it onto top of a single pane window.
Hard question but, would be About how much would this help the Efficiency?
Would it turn a r1 window into say r2? Or would it be so little it wouldnt Even pay for the pane over the long run :)
Just a idea :) Thanks for the help