What would you consider to be a “pretty good” window in CZ5?
I’m currently in the process of comparing window quotes for a new build in Southern Ontario (CZ5).
What would folks consider to be “Pretty Good” target performance for this climate zone?
I’ve looked at full PassiveHouse certified, triple pane, tilt-and-turn windows (R8, R9 and above) and they all come at a pretty significant price point. I’m wondering how low I can go before I’m going to start running into comfort issues. And to be clear, my primary concern is occupant comfort, not energy savings. E.g., I’m planning on having window benches in the bedrooms for my son and daughter and want them to be able to sit and read there comfortably even in the middle of January.
Is an R5 (U0.2) window good enough? R6? R7? And yes I understand that R/U value is not the only metric, but hoping to use that as a bit of a common currency to compare products.
So, dear people, what is a “pretty good” window in CZ5?
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In the Pretty Good House book we recommend no higher than U-0.22 for climate zone 5.
I became a fan of the Passive House movement when I sat on a deep window sill, leaning against a large triple-glazed European PVC window, in 10°F weather and it didn't feel cold at all. They were around U-0.14 and cost less than many double-glazed North American brands.
No higher than U 0.22 so that implies about R4.5 or better.
Have you seen any good studies or comparisons of real world performance of different window specs from a comfort perspective? I'm totally sold on triple pane windows, but I'm actually wondering if I can bring myself down to thinner framed casement style window at something closer to a R5 and still be comfortable instead of a chunkier tilt and turn at the R7+ mark.
There are various studies but they aren't totally conclusive as comfort varies significantly. With rare exceptions, a triple-glazed window will always be more comfortable than a double-glazed window. The larger the window the more difference it makes. The closer you sit to the window the more difference it makes. The amount of clothing you're wearing makes a difference, so a window in a bathroom and a window in a utility space will have different impacts on comfort.
North American windows are available in triple-glazed options. I have triple-glazed casements from Mathews Brothers, Sierra Pacific, Loewen and Marvin all going in right now, at a variety of price points. If cost is a major factor, you can't beat Mathews Brothers. Their triple-glazed casements cost less than double-glazed windows from the other brands I listed.
Window specs are in U-factor, not R-value. If it helps you to convert to R-value, that's fine, but the window world operates on "U" and you'll quickly get a feeling for how U and R relate.
Thanks.
Yeah, I'm totally sold on a triple pane IGU -- can't imagine going with double-pane just for comfort reasons alone. I'll also be specifying pretty low SHGCs for the majority of my windows as I'm at least as scared of overheating in the shoulder seasons as I am about excessive cold in the winter.
But with good triple-pane IGUs, achieving a relatively high Uglass feels fairly straightforward. It's the Uframe and the air-sealing that the frames can achieve that I suppose I need to focus on.
But putting it all together, if someone told you they were selecting windows with Uwindow of 0.2, sounds like that's probably "pretty good" for CZ5? Is it worth it trying to push lower to the 0.18 or 0.16 range?
I can see the passive house certified stuff in the 0.14 and 0.13 range but it feels like overkill to me. Just like my walls would have had to have been somewhere close to R70 to hit passive house certification whereas I think my R22+12 walls will qualify as "Pretty Good" and will be more than satisfactory from a comfort and performance perspective.
Because window and glazing technology is advancing more quickly than wall insulation options, peoples views are a bit skewed. Even a U-0.14 window is a lousy insulator compared to a wall. You might be perfectly happy with code-minimum, U-0.3 windows. There is not a magic value where window comfort changes dramatically. Somewhere around U-0.2 to U-0.25 is probably the sweet spot, but it depends on the many factors discussed here. As with everything else about the Pretty Good House approach, there are no strict requirements, just suggestions and ways to think about things.
Our windows were, eight years ago when they were installed, supposedly Passive Haus certified. I don't recall the U factor, but sitting next to them on our window seat in January always makes me thankful we got good windows.
So, I'd get the best windows I can afford.
Steve, yours are Intus, right? Probably around U-0.11 to U-0.14 on the European scale, very roughly equivalent to about U-0.18 to U-0.20 on the NRFA scale.
Michael, where did you get your conversion from Euro to NFRC? The Guardian Europe website has a nice tool where you can get all the IGU data in any testing standard. The difference between the two is roughly 10%.
Just a rough, educated guess from dealing with both North American and European windows for many years. The way the values are determined are simply not transferable with any equation. Martin wrote about the reasons here: https://www.greenbuildingadvisor.com/article/european-vs-u-s-manufactured-windows.
> So, I'd get the best windows I can afford.
I understand the sentiment, but there's a lot to unpack here.
My CZ4 home has Andersen A-series double pane windows with different coatings depending on the orientation of each window. Could I have "afforded" triple pane? Sure. Am I sad I didn't put in triple pane? No.
On 99% of days, I will not experience a window related comfort issue. This past winter, we had a number of days that were below the 14F design temp, and I was not particularly uncomfortable sitting next to any of my windows.
"Get the best windows you can afford"... "Get the best plumbing fixtures you can afford"... "Get the best cabinets you can afford"...
None of these things are wrong in their own, but you do them all and suddenly you're talking about real money. (Not to mention that defining "best" is often a tricky endeavor.)
Everything's a tradeoff, but I will say this: If my options are (1) Triple glazed windows but Glacier Bay plumbing fixtures and garbage cabinets or (2) Double pane windows but Delta fixtures and Ikea cabinets, I'm going to choose (2) every single time.
Just for kicks and giggles I have some quotes to share with you on our project as I’m currently studying them.
These have been converted to be as much “apples to apple” as I know how to do. Every company did their quote a little differently and it’s hard to normalize them.
First quote was Marvin Ultimate - $89,120. These would be considered poorer than grade C windows. Not sure on u-factor but I think it was around 0.22 or so?
Next quote was Alpen Tyrol PH+ - $53,903 but I’m not sure it included shipping. Still trying to find out on that out so I’ll say $58,000 just in case. This would be considered a grade B window for passive houses. They are built in Colorado. It is very thick so there is lots of room between the triple panes for argon gas. This quote probably would have been $8,000 more expensive but we wanted white which means they don’t have to inlay the color material into the uPVC so it’s cheaper. These are the European style tilt/turn windows so air sealing should be very good for the life of the window. One concern I have about them is the “thin glass” that is the middle pane. Alpen used to use a suspended film instead of a third pane but more recently have switched to thin glass. My understanding is it’s similar to the glass on the touchscreen of your phone. It has only need done for about 4 years so I feel the durability is unproven. I can’t remember on u-factor but I think it was around 0.14?
Innotech Defender PH+ ~$86,000 This is built in Canada. They are also grade B uPVC windows but I believe they use 3 full thickness panes of glass. I think they’re around .13 on the u-factor.
Schuco Living 82 - $60,437 These were something I found on my own so Emu didn’t have them graded but based upon my research I assume they’re at least a passive house grade B window if they were grade by Emu. They are uPVC windows and all three panes are tempered glass. I don’t have the u-factor in front of me but I think it’s likely in that 0.14 range.
Smartwin Compact from Advanced Architectural Woodwork - not sure if sales tax is included in that quote so it’s either $65,519 or closer to $71,000. These are built about 25 miles from me in Levant, KS. They are a wood window and are graded as passive house grade A windows by Emu. Again, I don’t have the u-factor in front of me.
I know the people who make the Smartwin windows personally so I’d really like to go with them. Second choice would probably be Alpen. Pretty torn at this point.
Alpen has shorter lead times by quite a bit. We will get amazing service from Advanced Architectural Woodwork but they’re 6 months out.
Super helpful comparison! thank you for sharing!
I wouldn't expect the inner glass panes to be exposed to much that would be able to physically damage them, as the outer panes should offer protection. It's also entirely possible they are using specialty glass materials for those inner panes that are much more durable than the usual soda lime glass. I don't think you have much to worry about here -- once the window has been installed, the chances of anything happening to the window that could break the inner panes without also breaking the outer panes (in which case the IGU is shot anyway), should be exceedingly small.
Bill
Why in the world is Marvin so expensive for such a lower performing product?
Agree. I don’t know. It was their top of the line product but still…seems a bit outrageous.
Aesthetics and reputation (name).
Marvin is often the go-to for many luxury builders and other folks who value appearance over energy performance as the primary consideration, and Marvin does make a very well-made and beautiful window.
As well, Marvin's reputation for service is generally well respected.
This is comparing apples to orangutans. Marvin Ultimate (if I understand correctly) is an aluminum exterior, wood interior product. You're comparing it to [albeit good] vinyl windows.
If vinyl is an option, and you want to compare an American made window in traditional style to the European-style products, Michael Maines mentioned Mathews Brothers. Their pricing is very competitive, and I've heard nothing but good things about the product. (I've also spoken with them on the phone and they are incredibly helpful.)
I think you were replying to me?
None of the mfg’s I mentioned were vinyl windows.
Two were wood with aluminum exterior (Marvin and Smartwin Compact built by Advanced Architectural woodwork).
The remaining three are fiberglass reinforced uPVC which from my perspective is likely going to be at least as durable as wood and is arguably easier to get high performance out of them than wood. Schuco I particular (available from European Architectural Supply) can apply many different films to the uPVC during the manufacturing process that are able to make them look indistinguishable from wood when you’re 10’ away if that’s something that’s important to you. Probably less if you’re a casual observer.
I don’t really have any interest in vinyl windows.
uPVC and vinyl windows are the same thing. Most PVC window manufacturers now offer films so you can get any color or wood-look. I also use Shuco windows and like them but I can't tell the difference between their plastic and Mathews Bros' plastic. "uPVC" is just the European term for the same unplasticized vinyl that North American manufacturers use. There are differences in PVC composition and quality, but the plasticizer issue is a red herring.
Well boy, do I feel sheepish, lol. I did not realize that. Thanks for the clarification.
After our comment I set myself straight looking through old posts on this forum.
Thanks.
For future people who stumble upon this thread, here’s a few good ones for reference:
https://www.greenbuildingadvisor.com/question/pvc-vs-upvc-windows
https://www.greenbuildingadvisor.com/question/upvc-vs-fiberglass-windows
Don't feel sheepish, the European window industry has done a good job of convincing North Americans that uPVC is different. I have promoted the difference many times, until I started looking into it more deeply, along with a few other folks. I'm still a big fan of European windows, I'm just not a fan of using obfuscation to sell products.
Not to be snarky, but an unclad wood window these days in a custom building? maintainence nightmare, I’m sorry.chipping and Painting every 7 years minimum in most climates ? Presumably you are also looking at double hung, in which case , I hav eto think why even sweat the u values at this level. Double hung will never consistently perform at that level in a few years. nOBODY seems to add this cost to their cap expense. Alpen is intriguing, but as you say that interior pane is unproven-my understanding is they have gone from a thin film to apple retina screen type material,sounds promising but unproven.
The plans called for casement windows everywhere other than the fixed windows so all quotes were either casement or European style tilt-turn.
Bot of the wood options (Marvin and Advanced Architectural Woodwork) were aluminum clad I believe.
What are your recommendations?
Have you checked out cascadia from Vancouver? Excellent pricing for the performance. Only down side is they don’t currently have a lift and slide door offering.
one more option (which i have in my current build are tripple grazed tilt turn from Euroline Windows (i am in BC Canada so if they are around your area they may come in less than Schuco but are more in the .20 range for u factor). Otherwise the schuco look like what i would be doing from the numbers i see (but it is not my money so it is easy for me to spend :).
I ordered and recently received and installed white Alpen Tyrol windows. The shipping from Colorado to CT was about $4500. You need to supply the crew to unload the truck. CT also started collecting outside the state Sales Tax so that was another $5500.
I'm very happy with the quality. There were some mistakes/issues that Customer Service seems to be handling with no problem. You can also order low SHGC as a no cost option.
When I did my cost study they were about 22% more expensive than double glazed Marvin but cheaper than Shuco. I think I would definitely buy them again, although we haven't begun living in that building yet, so it's a little too early for a complete review.
i'm considering tyrol as well, few random questions:
- did u go with the thin center glass option?
- did u install them with nailing flanges or cleats?
- did u get any sliding-doors from them as well?
- any tips/tricks on the install? what kind of tapes did u use?
- assuming they came with the little gas tubes u had to crimp, how was that process?
- did u get the insect screens?
-Thin glass? I thought it was the only option.
-flanges
-yes-haven't installed those yet. very expensive, Also got two zenith sliders to save money
-normal install. prepare sill (tilted or cedar clapboard) with zip and stretch tape. Caulk top and sides, install window, tape again.
-crimping and cutting the tubes was easy. I also stuck the cut end into a silicone caulking tube for extra sealing.
-did get insect screens. One wasn't perfect so I made a warranty claim. No problem.
Also specified muntins since our house is old New England style. This mimics the double hung look. Came out nice too.
thx for the extra detail nick!
- wrt sliders, r u saying that u got both tyrol and zenith sliders and that the tyrols r more expensive than the zenith? that would surprise me as i was told that zenith r about 10% more then tyrol (but maybe the sales guy was referring to windows v sliders...)
- did u literally install the windows yourself?
I got a large Tilt&Glide Tyrol for our sunroom that faces the water. I think it was $5800. There are two small upstairs bedrooms that will have access to a new roof deck facing the water. I used regular Zeniths sliders up there since they will rarely be used. They were about the same size and cheaper since they were just sliders and not Tilt&Glides.
I did not install these windows myself but could have. I have installed other windows in the past. As long as the RO is pretty square, it's easy peasy. Just remember these Alpens are much heavier than normal windows. Measure, check, measure, check, measure , check. ; )
I have some level of innate reluctance to (u)PVC windows, and as such, I'm having a hard time understanding what exactly these "fibreglass-reinforced-uPVC windows" actually are. They feel like 90% PVC windows with a bit of fibreglass thrown into some areas for structural strength. But they're first and foremost PVC windows...not fibreglass. Right?
So my lean is towards aluminum clad wood windows for aesthetic reasons. Or even full aluminum. Obviously that pushes up the price and lowers the set of available options. But there do seem to be some options out there from companies like Fenstur, Vetta, Zola and Ikon that seem pretty good. Just varying levels of pricey!
All PVC windows are composites, not pure PVC. Adding fibers increases the strength of the base layer but the face layer has to be fiber-free so it's smooth. Other PVC windows may have metal reinforcement instead, or in some cases they rely on the strength of the glass itself to keep the frame square. I really don't know the difference between "fiberglass windows" and "fiberglass-reinforced PVC windows" but I assume that fiberglass windows use a different resin and possibly more fibers.
Alpen describes their European based windows as:
"The Tyrol Series is a glass fiber reinforced polymer window and door system, produced based on REHAU GENEO® design–the first fully-reinforced polymer window profile system that doesn’t rely on steel for its strength. Instead, it is composed of RAU-FIPRO™, REHAU’s proprietary hybrid profile formulation in which PVC wraps a glass fiber via co-extrusion, combining the best properties of both materials into one – boosting size and performance while substantially enhancing the windows’ thermal and acoustic insulation capabilities.
Together, the Tyrol Series with RAU-FIPRO reduce expansion and contraction with enhanced structural rigidity while maintaining advantageous weld and bend benefits."
That makes sense. Fiberglass (embedded in resin) expands and contracts similarly to glass, while PVC moves a lot more with temperature changes. But fiberglass surfaces can be irregular so covering them with PVC, almost like a cladding, would make a nicer finish. It also makes recycling difficult but people rarely worry about that, for better or worse.
I believe Alpen’s Zenith series is straight fiberglass, if you prefer to avoid all PVC completely. They don’t make a tilt-turn in that series but it is still up to an R-10 for a fixed window and they have traditional operable types such as casements to choose from.
there must be a polymer but maybe they replaced PVC with epoxies or polyesters which allows a higher glass content and mechanical performance so basically slimmer frames.
Most of these Canadian options are sadly simply not functionally available/marketed/distributed anywhere south of Boston or west of Appalachia. Be sure to look at Enerlux windows in Crete Nebraska-full fiberglass, smooth exterior.super strong , Cardinal glass. Full custom color matching.
I see now you did make a recommendation. Thanks.