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Personal: Residential

Repairing or Improving
Existing Windows or Doors

Assess Your Situation

Carefully look at the condition of each window or door in your house. Skylights are typically not retrofitted. Check for ease of operation of each window or door, and note any defects.

Examples are:

  • loose joints or glazing
  • warpage
  • damaged or worn weatherstripping
  • rot
  • faulty hardware

Determine the airtightness and the condition of the caulking or weatherstripping.

Options include:

  • Repairing the unit – When a window or door is in good shape, adjusting or replacing hardware may improve its airtightness.

  • Retrofitting the unit – Caulking or weatherstripping can be applied to prevent air leakage through and around windows or doors. If the sashes are in poor condition but the perimeter frame is sound, you can retrofit the glazing and sash while keeping the perimeter frame and retaining the same window style. Figure 2

    Some problems can be solved without replacing the entire window. Drafts caused by air leakage, for example, may be stopped with a combination of new weatherstripping, new hardware and sealants. Interior storm windows that fit into or over primary window openings are another comfort solution that adds energy efficiency to an existing window. They are easy to install and remove. Costs vary. Some are disposable kits made from shrink-wrap plastic that are used only once, removed each spring and discarded.

  • Reglazing the unit – If the unit is in good condition, its thermal resistance can be improved by installing storm windows or doors. Figure 1

    If your double-hung window's sashes (the parts that move) and frames (the parts the sashes slide in) are in good condition, and you want to keep them, you can simply reglaze with double-paned, insulated glazed units that are custom-made to fit into the individual openings. If the sash isn't thick enough, you may not be able to do this.

  • Replacing the unit – If the glass in a window or door is fogged, it may need to be replaced with a new, insulated glazed unit. If the frame or other parts of the window, door are showing signs of deterioration, the entire unit may need to be replaced. Choose a high-efficiency ENERGY STAR® qualified product for your replacement.

    Figure 3

The ENERGY STAR name and symbol are administered and promoted in Canada by Natural Resources Canada and are registered in Canada by the United States Environmental Protection Agency.