you can replace double glazed units with new ones to rectify the problem,but get a double glazing repair company or glazier in your area to do this for you because it needs to be mesured right so it will fit or crack it as you fit it or you might need to get another 1 done. If you need any more advice go to my website and use contact page.
shaun www.sdwupvcrepair.co.uk
February 2008