Replacement Windows: Do I Have To?

We've been talking windows for a while here, and this post deals with a big item in the window market: window replacement. For a fee ranging from $300 to as much as $1000 per window, replacement companies will measure your openings, order windows, send techs to your house to remove trim and install the windows, and in many cases offer in-house loans for less-than-solvent homeowners in these troubled times. The pitch for replacement windows is built on two promises: looks and energy savings. Many companies promise lower energy costs and offer rebates or other compensation if their products don't save energy as promised.

We're not here to defame the replacement companies, or to question their claims in detail. Just hear me out. The performance of your windows is based on several factors, and you must calculate whether replacement windows offer you a desirable improvement in appearance, comfort and energy costs. You can't rely on people with something to sell when making those decisions.

Appearance first. The finish options on replacement windows usually cover several colors of vinyl and a few types/colors of wood, including an "unfinished" option you can stain or paint yourself. You will discover that the best performance and lowest prices center around vinyl/interior-vinyl/exterior models, especially if you'd rather not wait weeks for special ordering and shipping. All-vinyl windows are always in stock, depending upon size.

Now on to comfort. You will find that the most basic model windows feature thermo-pane dual glass and weatherstripping to seal the sashes to the replacement frame. You will be able to order performance options like Low Emissivity glass and sealed vacuum pane units with inert gas filler for lower conductive losses. The performance of thermo-pane glass with coatings over traditional single pane glass can be significant, on the order of twice as good. The pitch for better glass and vinyl sashes in your windows can be very compelling when considered in the small picture. Hang on for the summary, when we put all factors on the table.

Third item is energy savings. Here the conversation generates a bit of friction. Window companies speak of energy savings exceeding 45% as a result of window replacement, but warn that "results may vary." Of course. Other, more independent analysts figure the payback problem differently, suggesting payback periods of twenty or even forty years are a reasonable expectation. Be smart. Balance the claims of the window company against the data you get from contractors and independent energy zealots.

Let's sum up. Here's a kicker of sorts: the energy performance of a window is a combination of energy losses including conductive losses through glass, radiant losses through glass, and drafts and infiltration through sashes and around frames. Replacement windows, depending upon the installers and how much carpentry you're paying them to do, may address only conductive and radiant losses, leaving you with most of your drafts and air infiltration untreated, since the problem lies in your sash channels, framing and trim, where replacement window installers often fear to tread. The energy performance of a traditional single pane window covered by a glass storm window sealed to the outer trim can compete with that of a new replacement window.

Repairing/restoring windows is an intermediate strategy, somewhere in cost between low-cost window treatments (the link is to my earlier posts on window treatments) and full-on window replacement. And restoration/repair can yield energy performance and payback/savings that really work, rather than "results may vary." Friends don't encourage friends to spend borrowed money on an investment with uncertain results. If you have the cash, and you REALLY hate those old windows, you can shop hard and negotiate a good deal on replacement. Ask about the details of the carpentry. Use words like "infiltration losses," now that you know what they are. Replacement windows can dress a house up very nicely, and save energy in the bargain. But restoring your old windows, installing good storms, or interior treatments of the sort we discussed in earlier posts, can all save you money at lower risk, and these strategies should be considered before you apply for a loan and take a big step like replacement. As you noticed, in this blog we're all about the small steps. They get you there in the end, and I hate it when my friends fall down.