Drill the holes about four cm deep. When all holes have been pre-drilled, thoroughly clean the window with anti-static fabric and anti-static cleaner and replace it using the duct tape. It's going to minimize the level of heat you've got coming from a heating program. How powerful is secondary glazing? https://donovanatjzp.buyoutblog.com/26906260/diy-secondary-glazing-kits-options