How Retrofit Windows Can Save the High Cost of Replacement

It is almost sacred that replacing your current windows is the way to cut energy loss and save money. Without factoring in cost or historic considerations, it really is the best way to do this.

Despite this, a startling report by The National Trust For Historic Preservation (NTHP) states that:

retrofit strategies come very close to the energy performance of high-performance replacement windows at a fraction of the cost.

Translated, this means that the three retrofit (i.e., fixing) methods outlined below will save nearly the same amount of energy as replacing windows. Adding the factor of retrofit cost (low) vs. replacement windows cost (high) tips the scale in the direction of retrofitting, so that:

Retrofitting windows costs far less but has nearly the same effect as ​replacement windows. Three tactics--exterior storm windows, interior storm windows, and interior thermal blinds--will help you avoid the huge cost and mess of replacement windows.

  • 01 of 04

    Exterior Storm Windows

    New Windows Being Installed
    John Mills/Flickr/CC BY-SA 2.0

    For as long as homeowners have installed exterior storm windows in an effort to save energy and money, many window companies have equally derided these products as an inept attempt to fix windows that really need replacement.

    The real problem is that some homeowners purchase poor-quality storm windows; install them without care, and rely on storm windows alone to "fix" their windows. Complicating matters is the fact that many homeowners lack the skills or inclination to install upper-floor storm windows.

    The highest value storm window, according to NTHP, is a low-e "single-clear operable exterior storm; aluminum triple-track frame." While better quality storm windows are available, this window provides the best value, when cost is factored in.

  • 02 of 04

    Interior Window Panels (Inside Storm Windows)

    interior window panels
    By Rutebega (Own work) [CC BY-SA 3.0 (], via Wikimedia Commons

    The name may sound paradoxical: how can an interior window protect against storms? It cannot.

    Though it may not be the most accurate name, interior storm windows--which install parallel to your existing window--improve the thermal and air leakage performance of the window.

    While interior storms usually install permanently on fixed window units, it is possible to purchase ones that slide or swing away if you own slider or casement windows.

  • 03 of 04

    Cellular Blinds (Interior Insulating Blinds)

    Quilted Window Blinds
    © Window Quilt Insulated Shades

    Interior cellular blinds are made of lightweight fabric and open and close in an "accordion" fashion.

    When the blind is fully extended, a honeycomb-like structure forms a thermal shield between the cold window and warm interior. Some cellular blinds install at the top of the window frame, much like mini-blinds. The best blinds run along weather-stripped edge tracks to keep the blinds in place and the cold out.

    Equally good are quilted window blinds. These are made of thick, quilted fabric and roll up and down. Fewer choices of quilted blinds are available than cellular blinds, and some people object to their plain, utilitarian appearance.

  • 04 of 04

    When Window Replacement Is Not Possible

    How better to improve on cracked window glass, foggy glass, air infiltration around the edges, dated sashes, and a host of other old window problems than to put in newer and better ones?

    Even low-end cheap windows tend to be so technologically advanced (low-e, argon gas, etc.) that they far exceed the performance of old windows.

    There are two reasons why you might not want to do this:

    1. Cost: Even with a small house, few windows, and buying within a competitive windows market, expect to pay no less than $10,000 on windows. Think more like $15,000 to $20,000. That's considered cheap. And no, new windows will not pay for themselves in energy savings, not even over 30 years.
    2. Preserving Unique Windows: Fewer homeowners than ever seem to care about this, especially now that companies are making replacements that are more historically "in tune" with older homes.