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Should I Replace My Windows?

Posted on Oct 14 2008 by Alex Wilson

I get this question a lot from homeowners wanting to reign in their energy costs. Windows usually account for about a quarter of the heat loss in a typical house. State-of-the-art, triple-glazed windows (with two low-e coatings and kryptonA colorless, odorless inert gas, often used with argon in fluorescent lighting and sometimes used as gas fill in high-performance glazing. gas fill) will dramatically reduce that heat loss, so it would seem that replacing your windows would be one of the most sensible things we could do in buttoning up our homes—right?

Actually, the economics of window replacement are a good deal more complicated. Windows aren’t cheap—as anyone who has priced them recently knows. Top-performing windows with fiberglass frames and triple glazingWhen referring to windows or doors, the transparent or translucent layer that transmits light. High-performance glazing may include multiple layers of glass or plastic, low-e coatings, and low-conductivity gas fill. are significantly more expensive than standard windows. Replacing all the windows in a typical house with such products is likely to cost well over $10,000, and the “payback” for that investment may be longer than the length of time you expect to be in your home.

What to do? I would start by getting an energy auditEnergy audit that also includes inspections and tests to assess moisture flow, combustion safety, thermal comfort, indoor air quality, and durability.. A professional will examine your windows and should be able to give you a good idea of whether they need replacement. He or she may also be able to estimate what the energy savings would be from window replacement. (Note, however, that most energy auditors aren’t in the window replacement business, and they sometimes underestimate the benefits of window replacement.)

If your existing windows are in bad shape and need replacement, by all means upgrade with top-efficiency models—borrowing, if necessary, the extra money required to achieve this level of performance. The incremental cost of the high-performance windows (compared with standard windows) will be paid back through energy savings relatively quickly. But if your existing windows are in good shape, take a look at some other options before moving ahead with replacement—your energy auditor may be able to help you evaluate these options.

If your windows are a fairly standard size, it may make sense to replace just the sash rather than the whole windows. Sash replacement is a lot quicker and less expensive than whole-window replacement. If you replace older double-hung sash with new, your contractor may be able to remove the sash weights and insulate those sash-weight pockets (insulate with low-expanding foam sealant).

If your existing single-glazed windows are in reasonable condition and replacing the sash isn’t an option, installing storm windows often makes sense—this isn’t an option with casement or awning windows. Adding storm windows may even make sense if you have insulated glass in your prime windows, though the economic payback won’t be as fast.

I recommend outside-mounted, high-quality, triple-track, aluminum-framed storm windows. Quality is important, as they get a lot of wear-and-tear; triple-track means that there is an integral screen. Look for storm windows with low-e glass to boost performance. Harvey Industries, based in Waltham, Massachusetts, custom-manufactures such storm windows, though they have to be ordered through a builder or remodeler.

Since the low-e coating on a single-pane storm window will be exposed to air, it has to be a “hard-coat” low-e, which is more durable than the more common soft-coat low-e coatings. I have long looked for a quality insulated-glass storm window—so that you would end up with triple-glazed performance—but I’m not aware of any such product.

If your budget is too tight for new, high-quality storm windows, you might want to consider a less expensive, plastic, interior storm panel. If relatively handy with tools, you can make these yourself using materials available from Brown & Roberts or one of the local home centers. You can also order prefabricated, interior storm panels, such as those made by AEP Window Solutions, just across the Vermont border in Hoosick Falls, New York (518-686-9581). AEP custom-makes lightweight, removal, insulated panels (two layers of plastic) to fit your window frames at a significantly lower cost than replacement windows. The most budget-conscious homeowners or renters can simply tape or staple plastic on the inside of the windows—as I used to do—but this isn’t a permanent fix and it’s ugly.

Finally, you might want to consider repairing and air-tightening your existing windows—this can be done whether or not adding storm windows. Tom McLoughlin has recently moved to Brattleboro and set up a business specializing in window restoration. Thomas McLoughlin LLC Window Restoration (254-9370) preserves existing double-hung wooden windows, maintaining the historic character, while making them functional again and adding all-important weatherstripping.

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Dec 27, 2009 2:22 AM ET

Double pane storm windows
by Jerry Mc

We have original wood sashes in fair condition, but worth restoring since all of the interior oak window trim is unpainted and in very good condition. Our home is a 1920 Craftsman four square. We had wood frame storm windows made locally with double pane, insulated glass, low-E coated with warm edge spacers, for about $110/window. I had to paint the pre-primed frames and add the hardware to hang them, but we are extremely happy with their performance (foam weatherstripping seals them tightly). This is a simple, low-impact solution for older homes.

Dec 27, 2009 9:56 AM ET

Who made the storms?
by Alex Wilson

Jerry Mc,
Interested in where you are based and who made the storm windows. If you prefer, e-mail me directly: Thanks, -Alex

Mar 25, 2010 3:48 PM ET

Interior double Pane Storm Windows
by Satish Bhide, Architect, VP

Please let me know who made these double pane storm windows for you.
Is there any company which makes the interior storm windows with insulating glass with fiberglass or aluminum frame?
Well, It's not actually a storm window but an energy panel to save on energy consumption because the current exterior windows are single pane and historic on our project that is getting renovated.

Apr 22, 2010 11:40 PM ET

R+ Window Insulator
by Scott Dwire

There is a company in Utah that makes a double pane polycarbonate window insulator that has an integral frame/gasket that holds it in place and seals at the same time perfect for historic because it does not attach in any way yet increases performance 15-50%. Check out As a green builder/remodeler I recommend them because they provide a solution with the best ROI because you are sealing and insulating your windows without having to change them.

Mar 15, 2012 2:08 PM ET

Insulating Glass System
by John Smith

Another option for a Low E storm window here:

Looks like a nice product.

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