Climate Minute #2 Windows Appendix 3
Improving Double-glazed Windows
David Green’s book, Zero Carbon Home (in the Minuteman Library network), discusses options for installing a second/third pane inside the house. WinSert Lite (single-pane) and WinSert Plus are other options not covered by Green.
Another option for improving the performance of double-glazed windows is to install double-cell honeycomb shades and leave them down at night in occupied rooms, and all winter in unoccupied rooms. Blinds with side tracks seal all sides of the blinds, thus insulating significantly better than those without. Blinds Chalet is one of a number of firms that sells honeycomb shades with side tracks. Any reasonably handy person can install such shades by themself.