Since M started the blasphemous discussion of tear-downs and window replacement in my house the other night I have been lying awake thinking about it. I can see that double-paned glass is more energy efficient than single-paned, I know you can feel the difference. I know energy efficiency is environmentally friendly, in fact I hope that environmental friendliness will save the world, but I also know the enormous environmental costs of demo and new materials, that any salesman will inflate energy loss/efficiency numbers to their advantage, and I have seen how very restorable older windows are vs. the short life span of replacement windows.
I know Preservationists’ biggest argument is often about “the historic character” of something but we have to acknowledge that many people just don’t give a damn, and that’s, well, that’s fine.
While preservationists protested, a few other people were doing their homework and refuting window replacement with valid arguments. The following articles cite findings that the time it would actually take to save $$ on this big investment (replacement windows) was consistently around 30 years, more than twice as long as the time it would take to recoup the investment in repairing and restoring existing windows. Read these (non-pres) articles on the pros and cons:
The Great Window Debate
Update Historic Windows
Energy efficiency, the environment and historic preservation are all important to me, and in my world they go hand in hand. In light of that, I’ve done my best here to be a good journalist. I’ve been honing my argument and this time I won’t even mention the aesthetic appeal:
- Yes, double-pane glass is more efficient—it was a pretty great invention in fact.
- Before double-pane glass came around people used storm windows to achieve that insulating layer of air. Storm windows (I prefer exterior and operable for use with double-hung windows) are still a brilliant retrofit option.
- double-pane glass has gases between it that help filter UV and provide insulation, unluckily these can and almost always will eventually leak, leaving you with permanent condensation in the middle – yuck!
- New windows require less maintenance
- But the material is significantly lesser quality and unless you pay for custom built, high-quality wooden windows (an option many homeowners do, one at a time, when an old window really DOES get beyond repair), you will be replacing those windows wholesale in 20-30 years. Oh nevermind, leave that to the next homeowner.
- Exterior storm windows also offer protection from the elements.
- Most of the heat loss in your home is through the ceiling and walls, followed by the floor, windows and doors. Percentages range from 25-42% energy loss through the ceiling, 24-35% lost through uninsulated walls and 5-15% through windows. Hence, replacing your windows might feel warmer at the window but make little difference in the room’s ability to retain warm or cool air if the ceiling, walls, and floor are not properly insulated.
- Speaking of which, old wooden windows SHOULD NOT be drafty! if you are feeling a draft around your window, it’s not because it has single-pane glass, it’s because it’s not sealed well which is infinitely fixable! Panes may need re-glazing (the putty that holds the glass in from the exterior), weather-stripping updated and/or caulk may be needed around the frame where it fits into the wall. Weather-stripping is the easiest of DIY fixes.
- The replacement window industry wants us to buy new windows (duh), they’ve concocted all sorts of statistics and claims to make it seem like a no brainer. But even though their best claims were exaggerated, the damage was done, much of the general public was convinced that replacement windows would solve all their problems, and also:
- Driven by consumer demand, the Real Estate industry lapped it up and preached the replacement window gospel.
- Contractors will probably encourage you to get new windows too whether they believe in them or not because it SO easy to demo the old and install new and less time-consuming than restoring old windows.
- Additionally, sending all your old windows to the landfill in favor of all new material that will go to the landfill in another 20-30 years (because they can’t be restored thanks to the low quality) wins some major negative environmental points.
In short, replacing your old windows is not a pat answer to the problem of heating and cooling efficiency in homes, and it is certainly NOT the first thing you should do to improve efficiency. Although houses will be different, air leaks should be sealed (windows and doors as well as outlets, baseboards, can lights and other problem areas) and insulation added before anything else is done.
Industry jargon needs to be analyzed, whether it’s from a Realtor, the Window Industry, OR a Preservationist.
If I’m trying to improve my comfort and save $$, I would restore my wood windows hands down, seal drafts and make sure I have sufficient insulation in the attic and floor which will have a greater effect on the comfort level of the whole room. I might even install storm windows if I wanted to spend a little more money and really reap the efficiency benefits. If a window was so far gone it had to be replaced, I would certainly take advantage of double-paned glass, but get a good quality wood window custom built to match the others so that I wouldn’t need to replace all the windows in my house for aesthetic reasons.
What about metal window frames??
I don’t know much about restoring metal windows in mid-century homes, although it can be done. I do know the frame gets quite cold. So I’m not surprised that you’d feel a huge difference once the metal windows in a ranch house were replaced with new ones. In this instance replacement seems reasonable, though I’d still be sure to choose quality windows without plastic bits that break.