In my post, I pointed out that there is a high rate of failure of double-pane windows (leaking, fogging, etc.). Living at high altitude, most windows come here from where they are manufactured at low altitude. This increases the air-pressure related failures of double pane windows. I can get the benefits of double pane windows without the failure/warranty/ replacement hassle by having single pane windows combined with storm windows.

dottt1: you have needless worry.

I wouldn't say that the worry is completely without merit given the altitude issue, but I do agree with the other comments that insulated glass units will still be the best option for you.

1) Quality of product will have a profound impact on failures of every type, including the glass seal

2)There are manufacturers that take your location into account and accommodate that with the use of capillary tubes etc. I'd recommend reading up on that a bit, and then searching out some choices for your area that are proven to be reliable long term... and there most certainly will be some.

Thanks HomeSealed Exteriors, LLC. I feel a little better about double pane.

There is a reason that major national window and door manufacturers gave up their own insulating glass lines and turned to companies like Cardinal for supply. Their business is glass and only glass and keeping up with the everchanging technological advances. Having started in the business in the late 70's and seeing these changes and the ever increasing warranty terms for IG units, I don't think anyone that buys from a reputable manufacturer has much to worry about. Most units carry either a "lifetime" or a 20 year warranty which means the units will probably last 30+ years.

I know this thread is ancient, however I want to provide my 2 cents.

Imo double pane failure isn't an "if" but a "when" at least for models manufactured well into the 2000's. The problem is that double pane windows rely on a seal to keep their gases from leaking out. As far as I know, no one has a complete solution to the problem. Might not be an issue if you own your house for 5-10 years, however I have yet to find 20+ year old double pane windows without some problem units. Plan for complete replacement every 20-30 yrs.

Traditional single pane windows can usually be refurbished or repaired. The vast majority of double pane windows are truly consumable. Sure, advanced technologies exist to help prolong double pane life however you will pay for them. Note if you are fine spending $800+ in materials for each window you can still find some nice new double pane models with real wood muntins.

If you have old growth single pane windows in decent shape, I recommend refurbishing them. The putty may last for 50+ years. If you are buying new double pane from a mainstream manufacturer, I'd budget to replace them again in 20-30 yrs.

Yes, single pane window can be refurbished. What type of frame material are you talking about here? I am guessing wood by the "old growth" reference. There is a quite a lengthy discussion here that goes into the historical and architectural benefit of saving a wood window that is worth saving.

I am glad you started out this thread with the anecdotal acknowledgement of "in my opinion" (imo) because that is the vast majority of what this post is.

Cardinal and other glass manufacturers have seal IGUs gas leakage rates that are at or below Euro standards (i.e. less than 1% per annum) and the technology is only getting better. We replace almost zero failed glass in our experience and this is with units that were installed nearly 15 years ago. All manufacturing for that time was a human intensive process, so most of the errors and failures that we see are a direct result of the fabrication of the unit.

To claim that you will be buying new windows in 30 years is just an unsupportable accusation in this case.

Even if that WAS the case, I would argue that the math still might make sense in that case depending on the regularized restoration cost, fuel saving, and intangible of "home owner comfort". Living in a home with single pane glass or even some storm windows in a climate that is cold is miserable.

WoW, unfortunately it seems you are just supporting my main point that mainstream double pane windows are consumable. You will still see about 1% gas leakage per year even with a "perfect" gas seal. The data we have indicates mainstream double pane windows often fail between the 20 and 30 year mark, depending on factors such as weather exposure. While new windows may perform better we won't know for a few decades. Believe me, I'd like nothing more than to find a true solution to the gas leakage issue.

15 years is a short time considering homes are now often built to last 100+ years. Now if you come back in 25 years with the same claim (virtually no failures after 40 yrs) I may change my opinion. Again, if you buy the "Cadillac" with a 30 year warranty, the window company is still in business then, and they honor the warranty you may be fine. Unfortunately even then many warranties are prorated because the manufacturers understand that most double pane windows have a limited lifespan.

I'm not suggesting everyone run out and replace their double pane windows with single panes. I would just carefully analyze return on investment. It may be more cost effective to buy big box store windows (versus high-end double panes) and budget in a replacement in 25 years. Then you will also be able to take advantage of design/manufacturing improvements. You can also tint existing single panes.

WoW, by cold climate do you mean Alaska? lol. I've never had serious comfort concerns with single pane windows in northern New England.

Your argument is coming from a place of fact tech biker, but the numbers arent correct. Lower end “box store” type windows are typically replaced in 10-15 years. These are the same windows that you will see with excessive seal failures, rotted sashes (of wood) or bowed, leaking units (if lower end vinyl). A quality unit will last 30+, at least you seem to agree on that. I won’t speak for Wow, but it sounds like hes staying that between the energy savings and other benefits that would be reasonably gained on that minimum 30 year period, there is an ROI to be had there and there is plenty of data to support that. The number of people that believe that a single pane window being refurbished is comparable from that perspective is very, very small, there are probably more that believe the earth is flat, and one could arguably make a stronger case for that. Historical home where that character outweighs improved efficiency, comfort, maintenance, etc? Awesome. Refurbish all day, and ride your horse and buggy into town to get the supplies. Not a good plan for most though

Pretty sure I did the exact opposite of supporting your point.

At Euro-spec leakage rates (less than 1% per annum), the window that is 30 years old will have 70% of the intended R-value benefit from the gas and should only see about a 0.01 reduction in U-Factor performance. That is pretty much the exact opposite of what you were wanting to hear.

Compare and contrast that to the performance of a regularly refurbished single pane window (even with a cumbersome and unyielding storm window) and you will have saved enough to cover the cost of that window a few times over.

Keep in mind, have you seen how a 20 year old storm window works? How about the storm windows that allow condensation to happen on the interior surface of that single pane wood window and not dry out?

What "data" do you have and please feel free to share it as compared to just referencing it and promoting it as infallible.

I don't really care if you have or have not had comfort issues in Northern New England. Again, you are citing "data" and then using anecdotal examples as a defense. Logical fallacy, thy name is....

I don't know how high you have the thermostat turned up, how the home was built, what the CFM50 number on the home is and what your natural air change rates are.

There is a difference here between the argument being framed. If you will note in my first post after yours, I said "There is a quite a lengthy discussion here that goes into the historical and architectural benefit of saving a wood window that is worth saving."

I do not deny that historically significant wood windows are worth preserving in certain cases as the base material used in their construction just doesn't exist any longer (i.e. old growth timber strand). If they are restored (usually an expensive undertaking if you haven't priced it out recently) and combined with a well fit storm, you can get a reasonable level of thermal performance out of them. That all said, they are not without drawbacks:

• Tendency to condensation
• Lesser thermal performance as compared to an insulated and Low-e equip window
• Functionality difficulties when venting (i.e. two sections to open)
• Ease of cleaning
• Cost of the restoration
• Exposure to lead paint if undertaken by someone that is unfamiliar or ill prepared
• Complete lack of summer time performance with regards to heat rejection

There is no zero sum game in life or in construction. A newer window will certainly come with a cost, but I would argue (with the data to support said conclusion) that the cost of maintaining that single pane window and the additional fuel losses will easily outpace the cost of a well built insulated unit.

Couple that with the fact that the vast, vast majority of single pane windows aren't worth saving and it is a no-brainer for most folks.

I am helping a friend with a new home of hers. Should she consider keeping the single pane steel casements that are in her home as well?

Thank you everyone who took the time to share their knowledge and expertise with me. Clearly, I'm a dinosaur. I remember as a child every spring cleaning the windows with my mom, taking down the storm windows and putting up the screens. It seemed so simple, and the windows lasted forever. But, yes, times move on. I have a cell phone and laptop, a washing machine and dryer that have about a dozen settings each, a car with plenty of bells and whistles -- so, yes, it is time to get the modern windows, too. I've gone kicking and screaming into the technological age. But the case for double pane windows is a good one as energy efficiency is going to be more and more important as the planet heats up.

WoW, If that is true you assume the seals in your hypothetical window are still "perfect" at 30 years. Very questionable. Further, U value is mainly important in northern climates while SHGC is much more important in southern climates. Modern films can also often be applied to single pane windows to bring many performance factors (especially SHGC) very close to double pane (or better) for a fraction of the cost.

-"Regularly refurbished"? In my experience, good putty on a painted wood single pane window will last ~50 years. When the time comes, a quality contractor can perform the service fairly quickly. Last I checked about $200 a window, maybe less. Track and lock maintenance apply to new and old windows. What do you charge to install a high quality name brand double hung double pane?

-I've had no trouble with storm windows. They have all been easy to remove, install, and clean. Very durable. Never had an issue with condensation damage to the wood either.

-Most of your "drawbacks" are non or very minor issues considering the typical cost savings of maintaining existing single panes. Film and/or storm windows can bring single pane energy efficiency very close to new double panes.

Wood Single pane: $200 every 50 years for putty plus the cost to paint and maintain single pane locks and tracks (optional- plus perhaps $70 per window every 20 years for film).

Double pane: perhaps $600-$800 every 30 years for new quality double panes installed.

It's clear that it's usually cheaper to maintain existing quality single pane windows, even though energy performance may not be quite as good. Consider complete lifecycle cost.

WoW, sure I'm happy to provide data. I'm waiting for yours. Respectfully your post sounds just like a double pane replacement marketing pitch. Lots of talk but little to nothing to support it. A recent study and some data on clear single pane, double pane, and film performance.

https://cdn.llumar.com/drupal/na_arch_solar_specs_l2278.pdf

https://www.mdpi.com/2071-1050/9/5/731/htm

Not sure about the condition, size, access, or location of your friend's casement windows. Ex- If the casements open into a sunroom and still work well, why even consider replacing them (except for aesthetic reasons)?

I do a lot of rehabbing of old windows and repacing windows. I can not rehab an old window for $200 and make money. 9 times out of 10 the storm window is also shot. A home owner can do these rehabs for cheap if they don’t pay themselves just like I could still be driving my 72 dodge duster. Rehabbing windows have a place but unfortunately they wore out long time ago. . I understand your point and agree and disagree But let’s not sugar coat It .

Exactly Todd. Go call someone to re-hab your wood window and tell them that they are making $200 per unit, to plastic up the entire home, and see if you get a call back.

This whole hypothetical is BS at this point.

I got a quote to re-hab some historic wood windows and to re-glaze, re-weatherstrip, remove old paint, and re-intall...it was over $1000 per unit. Didn't include the cost of the storm, film, or anything else to bring the window into the 21st century.

Again...and for the last time...I think that historic wood windows ARE worth restoring if they are historic. That effectively applies to about <1% of the windows that are out there in circulation. Most of the older wood windows have either been replaced or are beyond repair.

For those 1% of the windows that do meet this qualification, yes. Restore them and put on a good storm.

resurrecting this old contentious thread, but I too would like to find someone who will manufacture excellent windows in a single pane for a summer cottage in the Great Lakes that sees huge extremes in weather. The cottage is uninsulated so insulated windows are not particularly useful and the homes I have had with high quality custom double paned windows have seen failures. The cottage I am replacing old windows in is on an island and not easily accessible for any type of warranty, and repairs cost a ton because you have to pay for the workers' time on the water as well. So I am searching for a custom window that can be made with single pane glass. The only company I found willing was LePage. If anyone has any knowledge of another, please let me know.

Marvin use to and perhaps still does. Aluminum clad exteriors would not be available A storm window may suit your needs,

Thanks. Lepage offers aluminum clad wood windows in a single pane if you ask. I have storms on there now and with sideways rain due to the ever present wind, they leak like sieves. I'll connect with Marvin and see if they will make them. I know it seems crazy to spend a ton of money on nice windows for a summer cabin, but i need something that does not leak and keeps the old cottage look intact (unlike the storms which look a bit tacky) But maybe I just need to see a newer, better storm window and see how they install that might mitigate leaking.

Cyn, sorry about the delayed reply.

I'd suggest just buying some vinyl Ply Gem 510 windows from Home Depot if your old single panes are unsalvageable. A 36"x72" 510 w/ argon, low e, tilt sash, etc. runs $198 in N Texas. Install should be simple/ basically DIY. Consider them disposable after ?20 years?. By then window technology will be even better so you'll be able to upgrade again. My friend paid $900 for 3 basic Milgard windows on sale and these 510's blow them out of the water. Just don't expect an authentic wood look on any of these cheaper double panes.

My 2 cents...

P.S. Leaks might be coming from around your old windows. I'd check your flashing to make sure it's still in good shape.

The old windows we have on the cabin are outside-mount storms. no flashing. I am looking to install real wood widows that function and are not storm windows (clad for ease of maintenance) so my question was who makes windows who offers single pane. It's not a cost issue, but a functionality and look issue, but thanks,I'll still look at those to suggest to my sister for her cabin. Vinyl is not a look option I will accept however for this 60 yr old cottage. Even the old storms look better than vinyl. They just don't keep windblown rain out and I am finally able to upgrade. Many cottage owners have upgraded to modern windows and many have had failures with the sealson their double panes because the cottages are not winterized. A single broken pane is easier to replace than a broken or failed double pane when you are on an island 7 miles by boat and 30 miles more by car to the nearest town And if anyone is looking, LePage does do them if asked. So I wondered if anyone had experience with others that did. It's always better to have a choice.

Understood! With double panes, I lean towards builder-grade or super premium wood due to the blown seal issue. Not a matter of "if" but "when" IMO. I'm pleasantly surprised by the Ply Gem 510's. They won't cut it in the looks department, however they are a mile ahead of decade-old builder-grade AL double panes. Note that the pictures on HD's website are outdated: https://www.homedepot.com/p/Ply-Gem-35-5-in-x-71-5-in-Single-Hung-Vinyl-Window-White-510/204293166

I'd check to see if there are any small local shops that will hand make single panes. Probably not many options because it's so hard to make a code compliant single pane. :(

Finally your existing single panes may be leaking because whatever flashing/sealing you have has failed. If you have no flashing, I'd be surprised if the windows haven't always leaked somewhat. New windows may not fix the issue if it's a building envelope problem...

there is no "flashing" and they have always leaked (originally a screen porch) It was a cheap solution at the time but now I am wanting true windows and intend to rebuild the front of the cottage to accept them.. The storms leak not only at the seals (this we periodically caulk) but at the joint between the 2 panes (the overhead pane is stationary the lower one can be raised). The wind drives so hard it drives rain in UNDER that joint. It's crazy. I think it actually deforms the glass. Definitely want a builder grade window to last a good 30 years. Thanks for your thoughts on this. I'll probably have to go with LePage. They did say they will use a much thicker glass than in the double panes