Window insulation kits
Available from: hardware stores, online Installation: DIY
These use a heat-shrinkable, thin plastic film which is attached to the window sash or frame using double-sided adhesive tape. It costs a fraction of the price of double glazing, yet still offers good performance in reducing heat loss and condensation in your home.
But there are drawbacks: it reduces the clarity of the glass, so is no good if you want to maintain a crystal clear view, and it’s only designed to last one season, although it may remain intact for several years if your windows are in good condition and the film is undisturbed. However, adhesive tape used on the film may leave a stain on the glass if you leave it on for longer than one season.
Window insulation film works on the same principle as standard double glazing by creating a layer of still air in front of the glass that acts as insulation, but you attach it to the window sash or wooden window frames, and not directly onto the glass pane itself.