For traditionalists or for anyone residing in a Conservation Area or detailed setting up, real timber sash windows are very likely to be the very first (and only allowable) option. These strips are generally suitable for draught-proofing a window with casements although not sash designs.  During the Confederate Military sashes https://banksyballoongirl56532.blogoscience.com/42127118/the-smart-trick-of-sash-window-draught-proofing-that-no-one-is-discussing