Double Glazing Window Repairs If your double-glazed windows are defective, you should repair them as soon as you can. If the seals are broken it can cause draughts and condensation, which can make your home less efficient in energy use. Repairing double-glazed windows is generally less expensive than replacing it. https://www.repairmywindowsanddoors.co.uk/goldersgreen-windowrepair/