Insulating shutters.

Double-glazed windows are poor insulators, with regard to both thermal and acoustic properties. Reports on study of insulated shutters for windows, sponsored by the SCBR and the National Swedish Board for Technical Development. Estimates that the energy loss through such shutters combined with a double-glazed window is about 0.7 w/m2K (compared to 3 to 4 for the window alone) and noise transmission can be cut by 15 to 20 db. Calculates that each square metre of shutter area could save an average of about 300 KWh per year in Sweden.