Secondary glazing of existing windows is an acceptable method for
reducing heat energy losses at wall openings. Providing the existing
windows are in a good state of repair, this is a cost effective,
simple method for upgrading windows to current energy efficiency
standards. In addition to avoiding the disruption of removing
existing windows, further advantages of secondary glazing include,
retention of the original window features, reduction in sound
transmission and elimination of draughts. Applications are
manufactured for all types of window, with sliding or hinged
variations. The following details are typical of horizontal sliding
sashes -Secondary Glazing