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Community and Q&A

Serious Windows vs. Thermotech, Fibertec, Inline, Accurate Dorwin

Claire Anderson | Posted in Energy Efficiency and Durability on

Does anyone have experience with Serious Windows or Canadian fiberglass windows? I’m having a difficult time finding high SHGC windows (with a U-value less than or equal to 0.30) for my passive solar home that are affordable. Looks like the fiberglass windows can give me the performance I’m looking for, but I can’t find any local installations to inspect the quality of manufacture.

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  1. GBA Editor
    Martin Holladay | | #1

    In case you haven't seen it, my latest blog discusses this question:

  2. Al Dueck | | #2

    DUXTON Windows & Doors, a Winnipeg based (north of Minneapolis) manufacturer of fiberglass windows has recently posted a wide range of performance numbers on the "Energy Star Cdn" site (USA still being processed) and I believe you will see a nice mix of SHGC and U values. Where are you located?

    Al Dueck, Pres/founder

  3. Claire Anderson | | #3

    Hi Al ~

    I'm in Oregon.


  4. Scott Heeschen | | #4

    I just went through that decision-making process, and ended up getting Serious Windows for my big south-facing clerestories, but Marvin Integrity for the rest of the house. I actually got a tweaked version of Serious' Heatgain 725 (using Starphire(?) glass) which gave a slightly higher SHGC without affecting the U-value. They've just arrived and will be installed in a few weeks, but they seem like they're built well.

    I got quotes from Fibertec, Inline, Serious and about 10 other window makers (but not Thermotech or Accurate Dorwin) - Serious was definitely the most expensive (about $60/sqft operable, $40/sqft fixed for their 725 series). Fibertec triple-glazed actually had slightly better performance at a lower cost ($50/sqft operable, $30/sqft fixed), but I was concerned that there are no local dealers. Serious Materials is located about 10 miles from where I live, so I felt if I *did* have any issues, it could be taken care of quickly. If I lived in the northeast, I probably would have gone with Fibertec.

    Good luck with your decision. It was tough, since we don't have easy access to that many options here in the US.

  5. Claire Anderson | | #5

    Hi Scott ~

    Thanks for the feedback. I've actually been considering using a combination of the Integrity windows and Serious Windows.

    If you had lights in the doors, what doors did you choose? Integrity? Our plan calls for a French slider, and I don't think Serious Windows make those.

    Did you go with a painted frame with the oak veneer or with white or a custom color?

    One person has remarked that the windows (from the exterior) have a purple cast. Did you experience that?

    BTW, if your home is a high-performance home, or near net zero, and you're interested in showcasing it to a national readership, I'd love to consider profiling it for Home Power magazine.


  6. Scott Heeschen | | #6

    The patio doors are Integrity outswing French doors. At the time I was making my decisions, Serious did not have their act together regarding their doors, and the word from the dealer I was using was that they didn't look all that great. We tried working with Serious and Eagle together, but Serious nixed that. I hope they have or will soon work out their plan, because it's nice to have other glazing options around.

    The Serious windows are all white fiberglass (I was too cheap to go with the wood veneer upgrade) - Integrity is a wood-clad ultrex, which looks pretty nice to me.

    I only saw the Serious windows in the warehouse of my window dealer, so can't really comment on the color. When I looked at the samples in the showroom (before ordering) they had some tint, but I don't remember it being any more objectionable that other LoE-type glass.

    My hope is to rely much less on the electric and gas utilities than I have in the past, and I've tried to move towards the PassivHaus standard, but I don't expect to meet it. Using PHPP, it looks like I'll come close, but I have no idea if I'm using the program entirely correctly (this whole remodel project has been a learning experience in so many ways). If things work out well, I'll let you know - I've enjoyed my online Home Power subscription and have gotten a few ideas from it along the way.

  7. Kori Fox | | #7

    We are a distributor in the Portland area of the Serious window and we do a lot of work at the coast. Serious does have the capability of painting there product to match any color. They have done several jobs to match Marvin colors. But of course this does add cost, where they are already somewhat expensive.

    We have samples of both standard glass options in the 725 and 925 series to show the color variation of the glass itself, as well as corner samples, and a full size casement. We have a customer who has installed the product in Happy Valley, OR that is more than happy to be used as a reference and/or show the product installed. Keep in mind the homeowners will be moving in around Thanksgiving. This house has the slate color window with brushed nickel hardware.

    We are currently with a builder who is expected to complete the first Passive House Certified home in Oregon and we are supplying this window. However we are still in a quandry regarding hinged doors. If anyone has suggestions I would love to hear them. Unfortunatley the standard products out there don't have the performance numbers we are looking for.

  8. Boulder, CO | | #8

    Word of warning, do not use Fibertec. I tried to save a few bucks by not getting Serious windows and paid for it. Poor customer service after the fact. Aside from very late, there was noticeable particles/ fingerprints between panes, gaps in mitered corner molding. Spend a few minutes searching Google and you'll find many complaints.

  9. Annette | | #9

    Cardinal Glass makes their E179 glass. I was quoted numbers like .60 to .70 SHGC and .29 U-Value. Jeld-Wen uses that glass. So far, I have not been able to find out if Jeld-Wen has tested that glass for a performance value on their window assembly.

  10. Ken Huck | | #10

    I installed Fibertec windows in a Superinsulated house. The Otahal Residence in Asheville NC. Two of the windows were huge about 55" tall and 108" long. I would say that the Fibertec windows were not the highest quality and they were a good value as they are much less expensive that the Thermotech. I will try not to install operable windows that large in the future. This house has been mentioned and here and it will be on the Solar & Green Home tour this Saturday 10 Oct 09 kwh

  11. Randy | | #11

    Probably out of the list, I would chose Inline. Taking everything into consideration and knowing they are all not perfect, the best value(price+quality+service+performance).

    West Coast maybe look at Cascadia as well.

    Let us know how it turns out.

  12. Andrew Henry | | #12

    I installed Themotech casements, a couple of picture windows (one that is quite large) and 8 small awnings for my addition. They are all triple glazed, two panes are low-e and specified to maximize SHG. I have some Marvin double hung windows in the original part of the house, double glazed with one low-e coating. All windows are argon filled.

    The Thermotech's were a real pleasure to install, and I have installed a lot of windows working for various contractor's in my varied work life. You don't have to spend much time fiddling with shims to get things aligned and the the fastening flange brings the window in tight to the wall, with flexible membrane sealing the flange to the wall it ends up being a pretty tight seal.

    The Truth hardware that Thermotech used on my awnings and casements is solid and high quality gear. The hardware does a very good job of drawing the sash tight to the frame, sealing out air infiltration.

    Having experienced very cold nights sitting near either double glazed Marvin's and the triple glazed Thermotech's, I can add that qualitatively the triple glazed windows make a home much more comfortable. You can feel the convection loops churning away with the double glazed Marvin's.

    That's my two cent's on Thermotech's. I'd install them again.

    A friend used them on one of his projects and the carpenters on that project also remarked how nice the Thermotech's were to install.



  13. Steven | | #13

    Thermotech's windows are not even Energy Star certified!!! They can claim what they want but can't find a third party who has objectively tested them. Something is not right.

  14. GBA Editor
    Martin Holladay | | #14

    On what basis do you make the claim that Energy Star windows are better than non-Energy Star windows?

    The Energy Star window program has always allowed northern climate windows to have any SHGC -- which is nuts. I'd rather have windows with carefully tuned SHGCs than Energy Star windows with very low SHGCs -- windows that were designed for Florida, but are sold up north because no one at Energy Star cares enough to prevent the travesty.

  15. Robert Riversong | | #15

    The Energy Star bias is reflected in the current (2009-2010) federal energy-efficiency tax credits, which apply only to windows with a SHGC of 0.30 or less !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

  16. GBA Editor
    Martin Holladay | | #16

    Right. A while ago I wrote an article on the insanity of the tax credit criteria for windows:

  17. Robert Riversong | | #17

    The apparent conspiracy of the federal government and the US window industry in preventing the widespread use of FREE passive solar energy for heating our northern homes reminds me of J.P. Morgan pulling his financing of the work of the greatest genious and inventor of the 20th century, Nicola Tesla, when his experiments were establishing the possibility of transmitting electrical energy across thousdands of miles without the distribution lines that allow corporations and financiers to meter and control it.

    When the corporate world finds a way to meter the sun, then we'll see the flowering of passive solar strategies.

  18. Scott Heeschen | | #18

    At first I was annoyed when I read about the stimulus as it applied to windows (what? SHGC of .3 or less?!?) but I easily spent enough on the non-south-facing windows to get the full benefit. It works out ok, but is a scary precedent. What's the saying? Simplify, but don't over-simplify? Seems like they've tried to make it too simple and not account for good reasons for having high SHGC windows. Plus the .3 U values are pretty wimpy - it'd be nice to see higher incentives for better windows to get progress going on that front, too.

  19. Steven | | #19


    Obviously you didn't read thoroughly my email. Thermotech's windows have not been tested by any objective third party. They can claim numbers/ratings they want. If they are the best in the world as they claim, PROVE IT! Inside a factory I can tweek a window until I get super ratings as well. But once they submit a window for testing to the NFRC and they can be held to the ratings and performance of everyday production, their claims are merely a personal review in rose colored glasses. How can you compare them to anyone else???

    Btw, my car gets 100 miles per gallon... I can state anything but where lies the truth.

    I did not state that Energy Star are better than non Energy Star, nor did I make such an outrageous claim. I simply pointed out fact that Thermotech's windows have not been tested by a proper testing facility. Please prove me wrong and if so, I will retract my statement and issue Thermotech an apology. The fact that 80% of windows are Energy Star means that anyone can make the list with a good piece of glass. But if their window is that good, why aren't they?

    Please advise.

  20. GBA Editor
    Martin Holladay | | #20

    Thermotech Windows have foam-filled framed made of pultruded fiberglass. Their casement and awning windows close tightly with multiple redundant weatherstrips. They use standard glazings with ratings that are easy to verify by consulting the glazing manufacturers.

    I have no reason to doubt Thermotech's window specs. However, I've e-mailed their technical director to ask for a response to your challenge.

  21. Steven | | #21

    So does, Serious, Marvin, Milgard, Owens Corning, Inline, Accurate, Fibertec, Duxton, Robert, Comfortline, Pella and Cascadia. So what is your point? I can find ratings on virtually everyone else.

    I've even heard that Thermotech even pays the $80/opening in Canada for not being Energy Star. This is the similar as our 30/30. Ask them if that is true as well while your at it.......

  22. Stephen Thwaites | | #22


    It's certainly true that we've never felt an affinity to a system that encourages mediocrity, Back in 1999, when we were part of Thermotech Windows, we did 'buckle' and got listed on the NFRC website. The testing was done by Architectural Testing of York PA. The simulations were done by WestLab's Jeff Baker.

    The thermal characterisitics on our website are from or consistent with that listing. We didn't renew in 2003 because building officials weren't (and in our experience still aren't) looking for NFRC stickers. More importantly it didn't seem to matter to our customers either.

    In the mean time neither the windows nor the laws of physics have changed. And we've continued to refine what we think, albeit arguably – especially with Passiv Haus people - is the most energy efficient window available.

    It's because of a Canadian rebate program; not the odd cheerful sentiment from competitors, we will be rejoining. Likely within the month as we're down to the dreaded paperwork. Careful observers might notice that the odd number will get marginally better; a reflection of the larger standard sizes used for these calculations for the last five years or so.

    Stephen Thwaites P.Eng.
    Technical Director
    Thermotech Fiberglass Fenestration

  23. Steve | | #23

    Are you or the Passive Haus people saying that your window is more energy efficient than the Serious Materials window? I'm sure most people would love to see a comparison.

    Could you provide us with one?

  24. GBA Editor
    Martin Holladay | | #24

    There's no way to compare two windows to decide which is more "energy efficient." It will ALWAYS be necessary to balance three factors: SHGC, U-factor, and VT. For example: one window may have a very low U-factor. That means that it won't lose much heat on a cold night. But it might also have a very low SHGC — meaning that it won't gain as much heat on a sunny day as a different window with a higher SHGC. The original window might also have a very low VT rating — meaning that although the window is good at resisting heat flow, it is terrible when it comes to admitting light into your home.

    Anyone could build a very low U-factor window by assembling 8 panes of glass in a fixed unit. But no one would like to live in a house with this type of glazing, because the SHGC and VT numbers would be too low.

    The holy grail window for south elevations in northern climates is a magic window with a very low U-factor, a very high SHGC, and a very high VT. That magic window doesn't exist, so we all have to choose the specs of our windows based on a series of compromises.

  25. Steve | | #25

    Then why does Thermotech's website say "the World's most Energy Efficient Windows and Doors". Furthermore, Stephen mentioned in the earlier email that Passive Haus also mention the same(response 22, 3rd paragraph)... How are they both able to say that without a comparison? Therefore, by your response no one can claim to have the most energy efficient window, correct?

    You must understand that I am just looking for straight answers, nothing more.


  26. GBA Editor
    Martin Holladay | | #26

    Thermotech's claim to make "the World's most Energy Efficient Windows and Doors" is, of course, a marketing slogan — just like Serious Materials claim that their model 1125 window will “save more energy than any other window” is merely a marketing slogan.

    Approach such slogans the same way you would any other advertising materials. The real data to look at are the SHGC, U-factor, and VT ratings.

  27. Robert Riversong | | #27

    Don't forget the all-important air leakage rating.

  28. James | | #28

    The question/concern in our minds is - How time-tested is seriouswindow's suspended film technology? I am reassured that serious offers a lifetime warranty on materials, but I don't want to be dealing with failing window units in 3, 5, 10, or 20+ years. In general, we know what happens with glass. How does this film hold up after years in the sun?

  29. sheeschen | | #29

    Claire asked way back at comment #5 if the Serious windows had a purplish cast from the exterior. Now that mine have been installed a few days, I can say they do, but it's really minor. With a normal double-pane window, there are two reflections, but with Serious there's a third. The one in the middle has the purplish cast.

    Speaking of this, I wonder what effect triple-pane windows have. They can never get the panes perfectly parallel, so those reflections "move" at different rates as you walk by. The third reflection seems to throw me off - I've gotten used to the two from double-pane windows, but am still working on getting used to the third.

    Build quality of both the Integrity and Serious seems to be good. Serious has more insulation in the frames, but the sizing of the Integrity frames seemed more consistent. The main frame with the Serious windows were spot on, but they had some large rim on the interior side of the nailing fin that didn't line up perfectly with the frame and varied a little (up to 1/8" or so). That plus the fact we only gave ourselves 1/2" extra for the RO of the windows added up to a little extra work for my contractors, but nothing bad. The Integrity windows, would probably have been fine if the RO were only 1/4" larger. My contractors also commented that the Integrity double outswing french patio door seemed more solid than others they had installed.

    I did call Serious with concerns I had heard with previous suspended film windows, and they stated that they pre-stress the films with heat so that they won't buckle or warp due to that. They also reiterated the lifetime warranty. My contractors and I have mused about how well any film material can deal with so much UV. I'm sure they're doing what they can about it, and hopefully it's enough.

  30. Kori Fox | | #30

    Speaking to longevity of Serious Glass and comment #28. Serious Materials purchased Alpen Glass in 2008. Alpen Glass has been manufacturing glass units with the heat mirror technology for 28 years. Serious Materials decided to use the technology by putting it into their fiberglass windows. There are numerous high profile projects that have used this glass such as; Viginia Air and Space Mueseum, Smithsonian National Portrait Gallery, Mount Rushmore Visitor Center just to name a few. Serious offers their life time warranty based on 28 years of performance data and history of their product in the market place.
    I would also like to say that I have seen the Serious Window installed in a project here in Portland and could not detect any optical effect due to the heat mirror. I realize that I may sound bias however Claire (comments above) also came out to view this project and has decided to purchase it (through us) for her upcoming project.

  31. Steve | | #31


    Not to be a wet blanket, but isn't Serious a different window in disguise. Thermotech is no more than a omni/comfortline window and serious a window pultruded buy another window company rebranded as their own.

    When are people going to realize the truth....there are only 5 true pultruders of fiberglass windows:Marvin, Milgard,Inline ,Omni and Comforltine. The rest are all just fabricators of the same window rebranded as their own.

    Btw, I believe that Comfortline is on the verge of bankruptcy. Carefull on the warranty....

    If you want more on who is is, more info, [email protected],

  32. Kori | | #32

    Yes Serious uses pultrusions produced by Inline. However I fail to see what this proves. Most window manufacturers purchase their lineals from someone else. Serious Windows is the only one that insulates these frames, utilizes the suspended film technology (with long record), and puts this all together in a high performance, reliable product.

    Are you saying that windows should only be purchased from a manufacturer that produces their own lineals? I fail to see this as an option if you want the performance and desire to purchase a product produced in the US.

  33. Kevin | | #33

    Hold the presses!!! Kori are you stating that Serious is the only company that insulates the fiberglass frames??? You have to be joking. Most companies have been around longer and have suspended film technology and therefore more reliable or YOU would have exposed them.

  34. Garth Sproule | | #34

    Anyone know what happened to Thermotech's website?? Seems it has gone missing...

  35. sheeschen | | #35 seems to be up at 9:19pm PST

  36. Garth Sproule | | #36

    They used to be at and there used to be a lot more info on the website including U values and SHGC for various glass types. Is this really the same company?

  37. GBA Editor
    Martin Holladay | | #37

    The Web site is down. I just spoke to Stephen Thwaites -- he says that he is working to solve the glitch, and the Web side should be back up in 24 hours or less.

  38. Garth Sproule | | #38

    Thank you Martin. I am still confused as to who is. This website and both appear to be using the same houses as references, the Hanover house, the Dumont residence, and the Katrin Klingenberg Passivhous....

  39. GBA Editor
    Martin Holladay | | #39

    The Thermotech Web site ( is back up. The landing page explains that Thermotech has been split into two companies. If you want to read Stephen Thwaites technical information, stick with the Thermotech Fiberglass Web site, not the Thermotech Windows Web site.

  40. Kori | | #40

    I'm not saying they are THE only company that insulates frames. Just the only American made (yes I know where the pultrusions come from). I don't understand what you are trying to say about suspended film? Again this glass has been made by this company (formerly Alpen) for 28 years. This is more than an adequate history for performance and longevity. I am happy to forward a longevity report ti anyone interested. There are very high profile projects with this glass. (Smithsonian, Mt. Rushmore Visitors Center, and many more). I am unaware of anyone else that has this kind of history with suspended film.

  41. T.C. Feick | | #41

    I read through this post. Lots of strong opinions. As a large supplier of many different brands of windows of various materials, here is the sad truth; 1: glazing options from most manufacturers are not good at all, and tuning your window for climate region or solar orientation is difficult, at best. 2: the largest of manufacturers, with the resources to drive appreciable change, offer little in the way of glazong options. Smallrt producers of high performance windows operate on a model similar to small vinyl window manufacturers. They are fabricators. So to the point about Serious materials "only" being a fabricator, I offer you this (I am NOT a Serious Windows Distributor); Would you not agree that the assembly of well chosen products is the most important facet of window manufacturing? You can choose the most efficient insulation in the marketplace, but if it is installed poorly, it has done the homeowner no good. As a side, there is a bill now pending to tie the tax credit U/SHGC values to Energy Star updated criteria; A step in the right direction. Support this bill Rockefeller/Grassley sopnsored, as it is the best way to drive market availability of high performance glazings. Want proof? I wonder if anyone has Cardinal's sales reports for #366 glass for 2q and 3q of this year over last? The large window manufacturers will respond only to market demand, and remember, they're the ones with large R&D departments (and budgets).

  42. Anonymous | | #42

    For the website try

  43. GBA Editor
    Martin Holladay | | #43

    Nope, that link -- -- is a different company that makes vinyl windows. It has nothing to do with Thermotech Windows of Ottawa, Ontario, a company that makes windows with fiberglass frames.

  44. Stephen Thwaites | | #44

    Just to clear up some confusion.......

    In 2005 Thermotech Windows Ltd. was split into two, now unrelated except by history, companies.

    a) Thermotech Windows Ltd.; resells windows and doors to the Ottawa, Ontario area.

    b) Thermotech Fiberglass Fenestration Ltd.; makes and sells fiberglass framed windows and doors locally, nationally and internationally.

    Hope that helps

    Stephen Thwaites
    Thermotech Fiberglass Fenestration Ltd.

  45. Randy | | #45

    So both companies sell Thermotech fiberglass windows, right? I just checked both websites, you really have me confused?

  46. J Yosso | | #46

    Where are you located? I am a serious window dealer in the portland or area,and would be happy to show you some installations.

  47. Stan | | #47

    Sounds like you had some great options...a few years back we installed Accurate Dorwin fibreglas windows on the whole north face of our two storey Winnipeg, MB home..along with a couple of others along the south and east side...these were by far the best windows we ever had...tremendous strength and quality...the service and installation experience was the best trades related experience we have had in 25 plus years of building/renovating. The windows were triple pane, low E, argon filled units that cut out neighborhood noise and eliminated drafts. We have recently built a new home and our Jeldwen vinyl windows are terrible in comparison.

  48. Monica | | #48

    We are about to build our retirement home and I have been researching window for about the last six months. Serious Windows continues to come up to the top of our list for all of the performance data. Our disadvantage of being in the Midwest is that we are pretty much buying these windows on blind faith...there are no local installations in our area that we can see. That makes our Architect and builder very nervous. Can anyone help ease our fear of buying windows over the internet? Who spends $55,000 without ever seeing what they are about to get?

  49. Ine | | #49


    Where in the midwest? I have Serious Windows in the house I am building and would be happy to show them to you/talk about them. The house is in Michigan's Upper Peninsula. I know the dealer also did another house in north central Wisconsin.

  50. Anonymous | | #50

    I arrived here looking for some information about Serious windows. Is it going to be a viable window manufacturer 50 years hence? Apparently they are doing a lot of research, creating very energy efficient/expensive windows, but most of us are not in that market. The question most of us have is who is providing the most bang for the buck, quality of manufacture, durability, and energy efficiency. The windows I'm considering replacing and have replaced were installed a hundred years ago. Yes, they were maintained, painted, glazing replaced, rechaulked, etc. Now, apparently, for energy savings we have to throw away our windows every 20 years and get new ones. To my knowlege, no one manufactures a sash where when the glass seal fails, or the glass gets broken all you need do is go to your local hardware store and buy new glass. As for being green, the direction window manufactures have taken us appears to be contradictory. What are the energy cost of manufacture and how much oil is being consumed to manufacture all this plastic. I don't know, maybe it is just a by-product supporting the gas consumed on the road.

    I do know, back in the early 1900s there were standards, and glass sizing was largely consistent. If a window gets broke in my house I go to the hardware store and he pulls a piece of glass out of a box and gives it to me. He doesn't have to cut it; the size is common. In my opinion, green needs to take the whole picture into account, including manufacture, maintenance, and product life.

    Sorry, a bit off subject.

  51. Riversong | | #51


    You're not "off subject" at all. In fact, your complaint is equally applicable to almost every product we buy and use today. There is very little in the "green" movement that is truly sustainable or earth-friendly or even sensible.

    Here are the criteria that Wendell Berry, perhaps the greatest living philosopher in America, uses to discern the appropriateness of any new technology or tool:

    1. The new tool should be cheaper than the one it replaces.
    2. It should be at least as small in scale as the one it replaces.
    3. It should do work that is clearly and demonstrably better than the one it replaces.
    4. It should use less energy than the one it replaces.
    5. If possible, it should use some form of solar energy, such as that of the body.
    6. It should be repairable by a person of ordinary intelligence, provided that he or she has the necessary tools.
    7. It should be purchasable and repairable as near to home as possible.
    8. It should come from a small, privately owned shop or store that will take it back for maintenance and repair.
    9. It should not replace or disrupt anything good that already exists, and this includes family and community relationships.

  52. Anonymous | | #52

    NEVER BUY FROM SERIOUS MATERIALS! I am an owner of Kensington windows, I had installed 2001 and reinstalled 2002, after legal issues with Kensington and US Remodelers. Right after 2nd install the windows need caulking over as the vinyl expands/contracts in extreme weather here. PLUS the product material IS WAY INFERIOR.... I can feel the cold and hot on the window glass and frame. Mind you, I bought top of the line windows and spent $15,000.00. Now I have not save any money in my electric or gas, my gas actually went up. I hired a lawyer and structural engineer, and window company to document the windows were installed correctly. It is the product material, I even have 1 window seal broke while 2nd install and with Serious not honoring Kensington lifetime warranty AND they are reopening the plant to make the same inferior windows..... my guess is! TO ALL CONSUMERS>>>>NEVER EVER BUY FROM SERIOUS they will never honor your warranties under their name, and the window are inferior.....I have to now spend another $15,000.00 to replace vinly windows that are not R-9 rated as you so boast about..... come to my home in Flower Mound, Tx and see what kind of windows you are making a huge mistake on AGAIN, but under a different company name!!! I am posting on all websites to warn our consumers you DO NOT HAVE A GREEN nor ENERGY efficient window product... AT ALL!!!

    I have the electric and gas bill to prove it! You are hiring the same employees and manufacturing out of the same facility my windows are not performing.

    You are thieves!

    1. Think about it…they are using same plant and materials from Kensington to build these windows.
    I invite the Energy Conservationist , Serious Materials CEO, President Obama himself to see that these
    windows are not green friendly, not efficient in lowering my electric and gas bill, and since I only
    got a lousy $1,500 credit on an initial $15,000 investment, I HAVE TO SPEND ANOTHER $15,000 to
    get PELLA windows as I believe they will be around in the next 10 years and NOT SERIOUS MATERIAL.

  53. GBA Editor
    Martin Holladay | | #53

    Dear Anonymous,
    If you have a legitimate complaint against Serious Windows, I'm sure you will be willing to tell us your full name.

  54. Riversong | | #54


    Why does this website allow "anonymous" comments?

  55. GBA Editor
    Martin Holladay | | #55

    Two reasons:
    1. Every Web site change that requires programming is expensive. There are many Web-site redesign ideas we have been kicking around, but we don't have a magic wand to implement them yet.

    2. As I'm sure you realize, if you ask everyone who posts to provide a full name, that doesn't prevent posters from choosing the name Mickey Mouse.

    With a little policing, and a little common sense, and a little bit of open discussion of the validity of fringe opinions — in other words, with the current level of controls — I think the GBA community is doing a fairly good job evaluating the validity and seriousness of posted comments.

  56. Riversong | | #56

    and a little bit of open discussion of the validity of fringe opinions

    By which, I assume, you might be referring to my own ;-)

    P.S. The level of discussion on this forum, as technologically primitive as it is, is an order of magnitude better than most other building forums.

  57. Kim Jones | | #57

    Who is this nut "anonymous" griping about kensington vinyl windows on this thread? Serious bought the equipment that Kensington used after they closed (they did not buy the company). And then installed new equipment to make higher end vinyl windows in PA. They don't even make their fiberglass there. There is no relationship to Kensington windows that "anonymous" bought 10 years ago. Different product and different company. What a lunatic.

  58. user-669103 | | #58

    I replaced most of my windows with Serious Windows, well Alpen before Serious aquired Alpen, and am extremely pleased with them. I have a mixture of vinyl and fiber glass units.

    I live on Long Island and have shown my windows to people before.

  59. Nancy Jordan | | #59

    Hello Claire,
    Since everyone else seems to have had a say in what windows are best to use, I might as well toss another log on the fire. I am the Domestic & Export Service Coordinator plus do a few other things at Accurate Dorwin Company in Winnipeg, Manitoba. Accurate Dorwin has been in the window business for over 55 years as well as developed & introduced the "pultruded" fiberglass window system in 1983.
    We are NFRC Certified & have our windows in many LEED & Net-Zero buildings. We ship windows all across Canada, Eastern, Central & Western USA.

    Please give us a call & we can answer any questions you have.

  60. Tore Fossum | | #60

    Here is a little post script on Serious Windows. It was recently reported by John Stossel in Real Clear Politics that Serious Windows (Serious Materials) was praised by President Obama, visited by VP Biden, and got a $500,000 tax credit. The very interesting fact is that Cathy Zoi, who oversees $16.8 billion in stuimulus funds, much of it for weatherization programs, is the wife of Robin Roy, who is VP of policy at Serious Windows. Could there be a conflict of interest in this award? I believe I will use a different brand.

  61. Riversong | | #61

    It's true that upstart company Serious Windows has been given special attention by the Obama administration and there is at least the perception of conflict of interest, but it's also true that Serious CEO Kevin Surace was named 2009 Entrepreneur of the Year by Inc. Magazine. More importantly it's true that CA-based Serious has been buying shut down window factories around the country and putting their employees back to work, including the Chicago Republic Windows and Doors plant at which employees staged a sit-in after being told of an immediate shut-down and loss of accrued benefits and the PA-based Kensington Windows after its parent company's bankruptcy.

    While John Strossel may have exposed some political favoritism on the part of the administration, let's keep in mind that this libertarian free-market advocate, who was apparently fired from ABC's 20/20 for trying to kill health care reform, now works for Fox News and appears regularly with that paragon of journalistic virtue, Bill O'Reilly.

  62. Monica | | #62

    We are in Lake Geneva, WI. We'd be really anxious to see an installation, and talk to a "local" dealer. Thanks!

  63. Colleen | | #63

    I'm located in Northern MN. My husband and I are designing a Passive Solar House while keeping building costs at or below industry standards for a typical home. This has proven to be no small feat but we're pulling it off. The issue of windows is HUGE and extremely charged on almost any website or blog. After reviewing all the research and data we can get our hands on AND considering the cost and the environmental impacts of the design, development, transportation and the product itself, we haven't been convinced that vinyl or fiberglass windows are the way to go. We're seriously looking at H-Window ( Their customer service has been supurb; they are custom-made so sizing and specs can be chosen on a case by case basis; they are assembled locally as are the components that go into their assembly; their materials are sustainable; their performance has been third-party reviewed; they've been around for awhile and their price is competative with mass produced and mass marketed products. During this multi-year experience, we've concluded one windows and best building practices should be determined on a case-by-case basis with basic regionally-determined generalities taken into consideration.

  64. Riversong | | #64


    From the limited information on their website (they don't list whole window values), H Windows have only mediocre thermal performance. Extruded aluminum exteriors may be more durable than aluminum clad wood, but will also have a significantly higher embodied energy.

    They seem to be a window company that is unique primarily because of its hinge design. That isn't a lot to recommend them.

  65. Mike C | | #65

    Check out Norwood Windows of Canada

  66. Garth Sproule | | #66

    I just checked out Norwood's glass they offer is dual pane low E argon filled?? That is not even close to state of the art for a cold climate window.

  67. Alfred | | #67

    Serious, is the way to go! They offer the best protection hands-down. The price is high, but the quality is unbeatable.

  68. Brent | | #68

    Finding this site was great. I am building a new home in Southeastern VA, near the Chesapeake Bay, and have been spending a lot of time trying to decide which windows use. Southeastern VA does not have arctic winters—although mid-Jan and Feb. can have a few bitter cold weeks—temps in the teens. Summers are hot and humid. Not shooting for Passivhaus, but building the house with energy savings in mind.

    Anyway, I've distilled my search to 3 manufactures: Thermotech, Inline, and Heinzmann European Windows. So far I've gotten quotes from Thermotech and European windows. Both were pretty expensive. The Heinzmann window is double glazed, vinyl and steel framed, and built like a tank.. I visited their distributor in Georgia, and was pretty impressed. I was actually even more impressed with their French doors. Their website is also a bit more informative than most.

    My experience with Thermotech has so far been less than impressive. I was leaning toward a fiberglass window, having been sold on it as a better frame material. As has been mentioned, Thermotech are triple paned with two low-e panes that can be specified to maximize SHG given varying window orientations. I also thought that Canada being closer than Germany, replacements or help with a problem would be less of an issue. On the downside their website offers almost nothing. I'm not even sure what their product looks like. I've asked for a photo of their casement windows and hardware and have not yet received anything. They cannot do arched windows, which came as a disappointment and a surprise. Tech support seems lack luster and seems to consist of repeating how their windows are beyond compare. Although in their defense, I may be on the low end of the food chain when it comes to digesting some of the technical data on their products.

    I should be getting a quote soon from an Inline distributor in Salem, VA. Having a distributor in VA is a plus. I like their 300 series casement window. Fiberglass frames triple glazed. (The guy from Thermotech told me Inline could not compare to their window, although I could never understand why exactly.) I'm curious to see how they compare price/value wise

    Does anyone have any experience with Inline or Thermotech, or Heinzmann?

  69. Anonymous | | #69

    Cardinal LoE172

  70. Riversong | | #70

    More unhelpful "information" from anonymous. It's time to stop allowing anonymous posting.

    Cardinal no longer makes lowE172.

    They offer loE²272: SHGC: 0.41 / U-FACTOR: 0.25 / TDW: 0.55 / LIGHT TRANS: 72%

    and loE179: SHGC: 0.70 / U-FACTOR: 0.28 / TDW: 0.61 / LIGHT TRANS: 79%

  71. homedesign | | #71

    Dear Campers ... please do not feed the bears.
    Dear GBA not answer questions by anonymous posters.
    Dear Anonymous (or Bogus screenname) please register under your real name and ask your question or make your comment again.

  72. Robert Dickerson | | #72

    I am located in beautiful lake tahoe (RE agent if you need one), and about to install triple glazed suspended film windows. I had traco heat guard windows in my last home and just loved 'em. Serious windows will be here tomorrow. My primary reason is to reduce noise, not too much about thermal. A coupla questions 1. is the sound reduction better in anyone's experience. 2. are serious windows and serious materials the same institution. Thanx

  73. John Button | | #73

    I am in the design phase of a new home to be located in lower Delaware. I have read all these posting as well as manufacturers manuals, etc. Given my income and building budget I am still at a lose as how to determine value in real dollars regarding windows/doors. Should I select average quality windows on price and invest savings in ICF/SIP, geothermal, roofing. How should an owner make some of these tradeoffs.

  74. William | | #74

    We also are looking into Serious Windows - replacements for our 75-year-old glass windows and french doors. Unlike most people commenting, our concern is not with heat loss but with cooling. We live in Los Angeles, and the house is high on a hill with south-facing windows, and we broil much of the year - it can be 75 outside and 80 inside. We're trying to lower our AC bills; we'll get some relief from gas heating bills, too, but the summer/fall (and sometimes even winter) heat is the main target. Our quote for Serious 725 windows was not a lot more than our quote for Milgard wood-clad fiberglass, and the Milgard dealer hasn't impressed us. What I want to know is: when it comes to insulating us from heat (not cold), what should we be looking for in layers of glass and R-value and U-value? This is a terrific site, BTW - very glad I found it, thanks of course to Google.

  75. William | | #75

    Oops - I should have mentioned that 75 to us is not hot at all - that's how badly our old house insulates us. The south side is all windows, and even with 75-80 outside we get blasted with sun (no clouds here!) and we sometimes have to run the AC, otherwise the house retains the heat all night even with windows and doors wide open. We can get weeks of 90+ and have to run the AC 24/7 because it gets so hot inside the house will never cool off w/o it. Shades don't help much at all.

  76. Al Dueck | | #76

    DUXTON is now listed in the NFRC data base and will be listed in "Energy Star USA" very shortly with an increasingly wide range of glazing options. Unofficially, DUXTON has also used a combination of AGC's new Krystal Klear low iron glass and EPS (hard coat low e glass) - CDN net zero demo program called Equilibrium - to achieve some quite impressive triple pane high SC with more than decent U values. However, wave length selective glazing requirement also means access to other products such as Cardinal's 272 and 366 in triple pane as well as AGC's TiAC40 means there are good options there. As important, all of those products are available with true warm edge in either Super Spacer or Cardinal's XL warm edge. The spacer options also ensure greater durability.

  77. Riversong | | #77


    Windows are rated in U-value, not R-value. Minimum U is always a good target, but more importantly you need a very low SHGC and perhaps some selective tinting as well.

  78. T.C. Feick | | #78

    Hey Robert, we could sell windows based upon R value as opposed to U-value... It is 6 of one, .1666 of the other. Made myself laugh there. DOE seems to be pushing these buttons a little with their R-5 window bulk purchase program... It seems that a U of .25 sounds so much better than U=.35, and it is, but we are talking R-2.85 as opposed to R-4. If I was a window manufacturer or sold them (which I do), I'd rather talk U value than have to talk R value. I spend a lot of time explaining as it is, and I really don't want to get walked over to a fiberglass batt by a prospective customer and then be asked to defend my window brand. Right on; "Windows are rated in U-value, not R-value."

  79. Riversong | | #79

    But it's not 6 of one, 0.1666 of the other.

    Even though R is the mathematical inverse of U, they mean very different things to the public.

    Though it might be arbitrary, R-value is how we compare insulation materials. U-value is how we compare heat-loss elements of a building's envelope, such as windows. No matter how insulative new windows may become, they will almost certainly be heat loss elements compared to our increasingly well-insulated walls and ceilings.

    And that's fine, since they serve very different and multiple design purposes: including view, daylighting, ventilation and aesthetics. So it's reasonable to trade off some blank wall R-value for the several unique qualities of glazing. But, since it's appropriate to consider windows in terms of how much heat will be lost (or gained in the summer), it makes more sense to compare them in terms of U-value (as well as Solar Heat Gain Coefficient, Visible Transmittance, Energy Rating, Air Leakage, Condensation Resistance, UV Protection, Center-of-Glass Properties, Whole Unit Properties...).

    Let's not confuse windows with insulation. Windows aren't meant to insulate - they're meant to do many other very important things that are contrary to insulative ability.

  80. David Jenkins | | #80

    My wife and I are planning to replace our windows (all triple casements) with a combination of Loewen and Accurate Dorwin. Loewen where we need a wood interior and Accurate Dorwin everywhere else. We live in Northern Virginia, but still feel that triple glazing and fine tuning the SHGC makes sense over the long term. Energy costs are only going to go up over time (maybe way up).

    Accurate Dorwin does not have a local dealer, but the company is easy to work with directly and provided me with quite a few references, which checked out. The big advantage Accurate Dorwin has over Thermotech is price. For some windows the difference was almost $1,000. Accurate Dorwin's price for triple glazed units are comparable to Marvin's price for double glazed.

    I will keep this thread posted on how the install and preformance goes.

  81. wjrobinson | | #81


    great thread needs more posts

  82. Brian O' Hanlon | | #82

    I decided to post up a new query on the use of units, so that people such as myself more familiar with the European system, can better understand these debates.

  83. Susie Harrington | | #83

    Excellent info so far---but need reliable recommendations for 8000 ft elevation windows in a log home construction. Location in Westcliffe, Colorado in a valley between 2 mountain ranges---high wind at times & 300 plus days of sunshine. Mostly casement windows preferred with some large picture windows with a SW exposure.
    I understand that not only are good materials important, but the proper installation, too.
    Any suggestions would be greatly appreciated.

  84. Dan Kolbert | | #84

    I had the opposite experience from David - got a higher quote from A-D than Thermotech.

  85. MzK | | #85

    HI...yes this IS a great site with a LOT of great happy I found this and some good price per sq ft estimates on Serious. After skimming through much of this and given my insecure nature about manufacturers generally speaking I will also get a bid from Pella with their Impervia with the foam filled option. I am absolutely demanding AT LEAST Energy U-factors. I'm in N CA....back later at some point

  86. Rudy Berg | | #86

    Most of us in the building trades have heard about Serious Windows. They’ve had lotsa enthusiastic press. Here’s my experience--

    Back in May I decided to try these for the my home remodel, and sent Serious Materials a query about local sources for their windows; they directed me to a fellow named Joe Yosso in Portland who runs a business called Northwest Energy Savers. Through Joe I ordered a set of replacement windows and on May 8 sent him a check for $5849. He advised me that the windows typically require 8 weeks to deliver.

    Six weeks later, on June 22, I asked that he provide a delivery date.

    Two more weeks passed with no answer. On July 6, I emailed him again, and he replied:
    Your file is on my desk this morning, ( we must be on the same wavelength) I know there were several delays due to the relocation of the production location, I will call this afternoon and see what the anticipated delivery date is... let me get back to you tomorrow...

    Another week passed, with nothing from Joe Yosso. On July 8 I sent this note to Serious Materials, cc’d to Yosso:
    On May 8, 2010 I paid Mr. Joe Yosso, DBA Northwest Energy Savers, $5849 for an order of Serious Windows. He advised me that the windows typically required 8 weeks to deliver. On June 22 I asked that he provide a delivery date. He has not done so.

    I have several questions:
    Is Mr. Yosso a Serious Windows dealer?
    If no, I'll proceed to bring legal action against Mr. Yosso.
    If yes, is his failure to provide even minimal service a reflection of his own or your company's standards?
    At this point the windows are past due, the project requiring them is stalled, and I have no idea when work can resume.
    I expect an answer by 5 pm Tuesday, July 13. Please note that any further inquiries I'm required to make will be copied to the following people:

    Chapter presidents of the Northwest EcoBuilding Guild, fellow members of the Cascadia Green Building Council, fellow members of the American Institute of Architects - Southwest Oregon, the editors of Architecture Week and the Forum of, etc.

    It won't be pretty.

    Rudy Berg

    That note got Yosso’s attention. At midnight he answered:

    I will check in the morning also, I will see how quickly we can get your order..
    I must have made him nervous, because he followed up with:
    Whom did you send it to at serious , so I can alo follow up ?
    On July 13 Yosso provided this update:
    I am expecting an answer this afternoon, looks like 3-4 more weeks, so I should have a date of 8/9 ship date from serious...I will see if I can get a rush on this, sorry for delays, I will see how I can make it up to you .

    And later that day:
    Not sure who will get that but nevertheless, your order is being worked on , and I expect a delivery date around 8/13 (shipping 8/9)
    I apologize for the delay, and my poor follow up, I had had some personal issues that have created some work related problems... I will try to compensate you for the extra time delay... would a 5 % discount account for some " aggrevation time"

    And then this note arrived, from the Serious Windows distributor:

    Mr. Berg—
    The message you sent to [email protected] regarding the order you placed with Northwest Energy Savers was received. A am very sorry you are having difficulty with your order.

    Northwest Energy Savers is a SeriousWindows authorized dealer. I’d be happy to look into the status of your order if you will kindly reply with the purchase order number used by Northwest Energy Savers to place your order with Serious Materials.

    Thank you,
    Dan Bedwell
    Regional Sales Representative
    Western States

    I sent a note to Yosso asking for the purchase order number.

    Yosso replied:
    the system is down, and I am not home to check the files, I will get info tomorrow... I also wanted to check where the exact delivery address is, they are shipping to me in vancouver and I need to divert to you directly if possible to speed things up ( at least by a day or so )

    July 20 Yosso emailed, but did not supply the PO number. Instead he asked for details on truck access to my project. I supplied those. It seemed like Window Day was approaching. I repeated my request for the PO number.

    On July 21 Yosso sent this encouraging note:
    Here you go Rudy...

    Good Day,
    We have changed the new delivery address.The anticipated ship date for your order is 8/11/10 . Standard transit time to your location is 3 business days which will put delivery on this order at @ 8/16/10 .
    Best Regards,
    Johanna Carter
    Serious Materials

    I wanted to confirm everything before it evaporated again. I sent Yosso this note:
    Thanks Joe. This means I’ll see the windows 8/16? Will the discount (5% x $5849 = $292.45) accompany the windows?
    He replied:
    Lets get the windows in your hands, then when you have your windows, I will personally send/ bring you a check .:-) maybe even buy you a lunch.... ( at the mcdonalds of your choice) :-)

    August 16 passed. No windows, and no word about them. --Finally, on August 29, I sent this note to everyone I could locate at Serious Materials, cc’d to Yosso:

    --Yes, the ones I paid for May 8.
    From this point forward I want no dealings or communication whatsoever with Joe Yosso. My cel phone is 541-915-3808. I want a call directly from Serious Windows by 8 am Monday, August 30 with details of a firm delivery date to my project address.

    On August 30, no call from Serious. Yosso replied:
    Looks like there is a small balance still showing due on this on their side... I willl take care of that within 48 hours and Finally get this out to you...... should ship this week.

    Later an SM rep emailed:
    I sense your frustration and do sincerely apologize for the delay. Your order is complete, however Northwest Energy Savers has not yet met the terms that would allow us to release this order to ship. Please contact Joe Yosso should you need additional clarification.
    Thank you,
    Dan Bedwell
    Regional Sales Representative
    Western States

    I reiterated to Bedwell that I was no longer willing to deal with Yosso, who had given me four delivery dates, all bogus. I called Bedwell’s cel phone, but no reply. The whole deal was beginning to smell really rank. For that matter, Serious Materials had also given me a fake delivery date, now two weeks past.

    The remarkable proposition is this: I’ve paid for the windows, and apparently they’d been built, but because “Northwest Energy Savers has not yet met the terms that would allow us to release this order to ship” I’m going to live with siding halfway up my walls into the rainy season. Of course, I can check with my new friend Joe Yosso about when that condition will end.

    And it’s occurred to me that even if the windows arrive, any window problem will bring me again to the doorstep of Joe Yosso, behind whom Serious Materials stands prepared to do, well, pretty much nothing.

    I’d like to report that the story has a happy ending. I can’t. As the guy said to the bartender, thanks for listening.

    Rudy Berg
    Common Practice Building Design

  87. Riversong | | #87


    And your point is?

    Apparently, you got yourself involved with an incompetent (at best) window distributor. Nothing in your narrative necessarily reflects poorly on Serious Windows as a manufacturer.

    If nothing else, your sad tale emphasizes the importance of avoiding middle men and dealing directly with the manufacturer's sales rep, such as is possible with Pella and Thermotech.

  88. user-659915 | | #88

    "Nothing in your narrative necessarily reflects poorly on Serious Windows as a manufacturer."

    Robert I have to disagree with this comment.

    Rudy dealt with an authorized Serious Windows distributor. At the point where SW became aware of Yosso's seriously unethical behavior as their agent they became implicitly responsible for sorting out the mess and they failed to take that responsibility. Their regional sales rep should have taken a pro-active role in resolving this issue as soon as he became aware of it. If SW are serious about establishing a name for quality in the industry they have to be as assiduous about their customer service as about their product or they will fail, with the consequence that purchasers will be left with an unsupported product. Seriously.

  89. GBA Editor
    Martin Holladay | | #89

    I agree with you.
    If Rudy Berg's account is accurate, then Serious Materials was notified of the problems with Joe Yosso on May 8. It doesn't sound like Serious Materials has adequately addressed this problem in the 3+ months since then.

  90. Dan Kolbert | | #90

    Well, actually, July 8, but still it reflects pretty poorly on Serious. And since they acknowledged that this guy was an authorized dealer it seems like it would have behooved THEM to track down the order with the dealer.

    We're about to order a houseful of Serious windows. Fortunately I've known the local dealer for years, but otherwise the story would make me nervous.

  91. Riversong | | #91

    We're about to order a houseful of Serious windows. Fortunately I've known the local dealer for years

    And that's the gist of the matter, isn't it? A manufacturer sells through local distributors so they don't have to deal with the retail customer. I don't blame them. So it comes down to the reputability of the distributor.

    Deal only with people you trust. That's the take home lesson.

  92. user-659915 | | #92

    "So it comes down to the reputability of the distributor."
    True. And like it or not, manufacturers will be judged by the behavior of those whom they select as *authorized* distributors. This is not like selling soap.

  93. Riversong | | #93

    Actually, it's exactly like selling soap. Far too may suppliers and providers of building equipment and services are salesmen, marketing with hype and false promises.

    For better or worse, in a "free-market" capitalist economy, it's still caveat emptor.

  94. user-659915 | | #94

    Robert you're confusing the issue by eliding the difference between 'selling' as in marketing and 'selling' as in entering into a contractual relationship with a buyer. I may agree with you in many cases on the marketing side. On the buyer-relationship side there is simply no comparison. If I purchase a bar of soap from the local convenience store I expect Proctor & Gamble to take responsibility only for the quality of the product itself: no-one would expect them to be involved if the store were to overcharge my credit card for the purchase. The store is simply a retailer and P & G does not endorse or authorize them or their business practices in any way. This case is entirely different: as an authorized dealer Yosso is an agent of Serious Windows and they share responsibility for his performance as he shares responsibility for theirs. In the open marketplace in which they both operate and where caveat emptor does indeed apply, his reputation is their reputation. Any manufacturer of a high-end consumer product ignores this reality at their peril.

  95. Riversong | | #95

    Well, I may be conflating marketing with contracting (though I'm not sure there's much of a difference in our economic culture), but you're misusing the term "elide", which means to omit or strike.

  96. user-659915 | | #96

    No Robert my usage is correct. You are eliding, omitting or doing away with the difference between the two meanings. Look it up.

  97. Riversong | | #97

    Allowing that your usage is a stretch of the common grammatical (to elide excessive text) and linguistic (to elide a consonant sound) meanings, it is nevertheless logically incorrect since it begs the question.

    To assert that I was eliding (omitting, suppressing, ignoring) the distinction, assumes a priori that there is a difference.

  98. user-659915 | | #98

    That there IS a distinction to be drawn, Robert, between the marketing and the contractual meaning of the notion of selling is exactly my point. You apparently feel that this distinction is insignificant, that is your privilege, and the language's loss.

  99. Anonymous | | #99

    Never buy from fibertec windows. They are horrible both design and quality wise.

  100. Riversong | | #100

    Wonderful. Another strident recommendation from Anony-Mouse.

    I'm putting out the mouse traps.

  101. Colin Meacham | | #101

    Well, Yowza ! I live here in Vancouver B.C. and I am researching windows to see what I can find out in order to make a well informed decision. I have looked a t Pella, Marvin, and several others out here. I have No interest whatsoever in Vinyl windows. Those are for people who are either Spec building, doing a Reno, or just have not got the time, energy, or money to care about what they are doing. That's just my opinion. From the very start of my research it is very clear that a Good Window starts with the glass, and how it is sealed. From that alone, companies that use Swiggle Steel, or products made in house similar to this are not as good as window companies using Super Spacer. The thermal conduction starts there ! Thanks to everyone who posted her I am able to now go and look at some other companies like Cascadia, or Duxton, or Serios. I will forward them my plans for the house and see what numbers I get back.I have already been dealing with Fibertec out east and the interesting thing was that the cost for my order was around 34 grand for double pane, and 36 for triple pane. That alone is a no brainer ! with the R Value doubled by going triple, and the sound advantage it's easy to say that the up-sale of a couple of grand makes sense. I am looking for a window that I can have a wood interior, so that too was something to consider. If anyone else has some insight or suggestions as to whom I might also consider please do let me know. I would like to buy local for all the reasons that entails, however if there is nothing close that meats that criteria, then I will have to go with whomever makes a good product that I can fit within my budget.

    No it's not like the old days, when you could buy a glass pane to replace the one that got broken ! but hey give your head a shake, we don't live in cookie cut houses, like the ones built back then. Today there is so much diversity in design, it would be hard to imagine all the different configurations that windows might be implemented into. You need a vacuum machine to seal the new windows properly, and lets not even get into gasses.So if you get a broken window it's a little more complex than cutting glass ! They still make windows to standard sizes, but it depends on where you live and how old the house was. We all live in different regions of this planet, and standard is really only a local term if you think about it.

    It seems that composite widows are making the best out of diversity of materials to get a better thermal break, and give strength. I want wood in the interior, and I think that Fiberglass seems to be a good choice for material of construction. I think maintaining fiberglass is probably akin to maintaining a boat made of the same.

    If you have some information as to whom I should also be looking at for windows please do drop me a line [email protected]

  102. Donald Lintner | | #102

    A little late, just saw your response from last April. We are building in Michigan's Upper Peninsula so not exactly local to Lake Geneva. I'm guessing you 've made your decisions by now but you can reach me at lintner at uwp dot edu

  103. Deniz Bilge | | #103

    My wife & I bought a home in Southern NJ (near Atlantic City); I tore it down and am trying to build an energy efficient home. I'm happy with my progress so far, except that we have lots of glazing, just under 25% of my wall space. I will need to purchase high performance windows in order that I don't negate all the work I've put into the place (if that's even possible). I'm sold on fiberglass at this point, but as far as the specs go, I'm not sure where to go.

    The winters are certainly not bitter, but 40 degree October evenings through 40 degree March days means heat nevertheless for about 6 months. 80 degree May through 100 degree August means 4 months of cooling. I figure a moderate SHGC, lower U-Factor, higher VT should be fine, especially fine tuned per compass orientation, but I wonder how long the windows perform at their energy ratings. I don't want to spend $30,000 on an energy rating that halves itself over 2 years and halves again 3 times over the next ten years.

    For example,
    How do I know there is still gas between the panes?--How long does it take how much of what type of gas to escape? Can just shipping to the job site (over the mountains and to the sea level) cause pressure changes which can lead to gas escape?

    Also, about insulated frames: are they open or closed cell? I imagine that it would be difficult to insert closed cell insulation in the frames, but once again, I don't know about the process. Anyway, will the open cell insulation (if used) off gas over time?

    Which manufacturers have effective systems to address these matters? Is there anything else I should consider that which I am not thinking of?

    Thanks for any input.

  104. Riversong | | #104

    While argon improves the thermal resistance of a multiple-glazed window unit because of its lower conductivity and increased density, the gradual dilution of gas fill over time doesn't dramatically effect the units's U-value. Though, if you see visual distortion it could mean that gas fill has diffused and not been replace by air, leaving a negative pressure which distorts the glass.

    Inert gas retention is dependent on seal material, spacer and desiccant selection and, of course, on the quality of fabrication. It's safe to assume that there will be no significant gas exchange as long as the seals are intact enough to prevent between-pane condensation.

    Fiberglass window frames will put less stress on the glazing unit, since they have the same coefficient of expansion as the glass. Wood frames are good. Vinyl frames are awful. Never use a glazing unit that has less than a 20-year glass warranty.

  105. Steve El | | #105

    Deniz, good for you for thinking about these things. Could you get price estimates for identical windows with and without the argon, and also get a quality head-load calculation showing the with and without numbers? (the key here is "quality"). Finally, factor in overall ecological cost to the planet with and without the argon. I don't know about leakage issues but I would be interested in what you figure out on the above questions, for your specific house.

  106. Deniz Bilge | | #106

    Sorry guys, I barely get time for this stuff, so it's been a few days. Anyway,

    Thanks for the info Robert. In other words, it's more about the film coating than the gas fill?.. I might be zooming in on a tangent a bit, but do you think there is more measurable performance in where the films might be placed, for example: on the inside of the exterior pane vs. the inside of the interior pane, etc...

    Steve, not sure what the head-load calculation is, including the with /without numbers part... No idea what that means..I'd appreciate the primitive man version.....As far as the price estimates, I don't think low e fiberglass windows with air fill exist, at least not with .21 u-factors, or .18 with krypton, and the 20 year glass warranty.

    Interesting point about the ecologics...(i have no idea where or how inert gases are collected)..In the case of the ecological impact of my house, I do think I've done a great job in minimizing the new resources and earth disturbances necessary to make this project possible; however, due to lack of options and inability for myself to fabricate them, I can't say it's big on my list in terms of window shopping.

    Appreciated input. Thanks.

  107. GBA Editor
    Martin Holladay | | #107

    If you are buying new windows, the upcharge to include a low-e coating or argon fill is a cost-effective energy-saving investment anywhere in the US or Canada. It makes no sense to save just a few dollars by ordering clear double or triple glazing without low-e or argon. For just a few more dollars you will save a lot of energy over the next few years, so ask for low-e argon-filled glazing.

    Of course, it's important to order glazing with the appropriate SHGC.

  108. Deniz Bilge | | #108

    I understand your point about getting gas fill, and yes, I do plan on it. I'm just trying to understand how close my $40,000+ investment will perform to the sticker specs 5, 10, 20 years from now. In figuring that out, I am trying to find out if anyone out there knows about the lifespan of the gas fill inside the window. For example, if it leaks out 40 percent between 5-10 years from now, what will my U-factor, SHGC numbers be then.

    Next, the films. How does placement of them affect the #'s; How many years of ultraviolet wave exposure can they take?

  109. GBA Editor
    Martin Holladay | | #109

    A low-e coating is not a film. It is a thin metallic layer. It can be applied to glass by one of two methods. Soft-coat low-e coatings are applied by "sputtering," and hard-coat low-e is a pyrolytic process.

    Here's information on the placement of low-coatings on double-pane IGUs. The information comes from a window expert who posts on Web forums using the name Oberon:

    "A high solar heat gain (HSHG) LowE coating will allow direct solar energy to pass thru the coating and will prevent heat from passing back thru the coating to the outdoors when the sun isn’t shining. This coating offers the advantages of passive solar energy gain with the advantages of the heat-blocking ability of the LowE.  Placing this coating on the #3 surface of the IG (the inner side of the interior lite) affords a bit more solar gain advantage as well. But, placing the coating on that surface will make the coating less effective in the summer months in keeping outside heat outside, so there is a trade-off. LowE coatings are generally placed on surface #2 – interior of the exterior lite – except in extreme northern climates."

    Argon glass is likely to migrate very slowly through the edge spacers of an IGU. It's hard to predict the rate, but it's safe to say that in 30 years, a measurable percentage of the argon will be gone -- maybe half to 3/4 of the argon. But the window will still perform, even if its performance is not quite the same as when it was brand new. And the energy savings achieved over those 30 years will certainly justify the investment.

  110. Joe Windham | | #110

    Research agrees with your assesment however, I have been trying for over 9 months to obtain pricing for anykind of Serious Window. I have called the company 6 times and they gave me information for dealers but I have never been able to obtain prices or have a human come to my home. I did talk to one dealer who told me about the Serious Fiberglass replacement and then told me I could not afford them. This is all I have learned in 6 calls and 9 months. I am about ready to go to Lowes and order from there. At least Lowes will give you the price and tell you about the windows.
    Joe Unsatisfied Serious Customer

  111. Deniz Bilge | | #111

    Joe, About the Serious quote---both "local" distributors I contacted (who didn't even handle the fiberglass window line) seemed more interested in getting an installation job than providing me with a quote for windows. When they realized I was only interested in the window, not the installation, they seemed to have taken it personally and were non supportive in helping me---"Nobody uses fiberglass windows around here. Vinyl's less than half the price", etc... .Anyway, quite frustruated with the judgements and lack of quote, I called Serious again, and they gave me the number for their national distributor.

    Much more professional. I called first, then corresponded with emails. I gave a list of the rough openings, the window types, and quantity of. TWO days later, I received a 4 page quote, describing the windows, options (color, grilles, hardware, etc), and price, schedule, and shipping. The national distributor is definitely the way to go, as they have been very responsive to all my inquiries,concerns, and information requests. They are even willing to send me corner /glass samples.

    Obviously, they're going to be marketing the Serious product to me, and not being a windows expert, it's hard to know if the Serious manufacturing techniques and materials are higher quality than the competition (in the short term and the long run too). I know they have great numbers on the sticker, but that doesn't tell me the whole story (for example, a new Stihl demo saw with 6800 RPM may be more than a 5400 Husqvarna, but the minute you cut something with it, I found that the 5400 RPM saw has more torque and power to make the cut). I am finding out information on this website, however, to help me in terms of having unbiased input about how window performance works. Anyway, back to the quote.

    The prices I rec'd... (all casement) just around $1000/window for the 525 series (depending on size) and add 20% for the 725. this is the without grilles price. grilles were avg. $300/window for the 525 series. The quote for the sliding doors were between $3-4000.

    In short, I am having a good experience with the Serious national distributor as of now, and those are the numbers I got.

  112. Deniz Bilge | | #112

    Martin, you're pretty smart. I just discovered this blog a couple weeks ago. I can't believe I can actually get information for free from people who know what they are talking about. Thanks.

  113. Riversong | | #113

    Placing this coating on the #3 surface of the IG (the inner side of the interior lite) affords a bit more solar gain advantage

    This is wrong information.

    The #3 surface, where the lowE coating is applied for high SHGC windows, is the OUTER face of the inner pane. The surfaces of a double-glazed unit are counted 1,2,3,4 from the outside in. The coating is never put on surfaces 1 or 4 as they would get damaged over time, and the role of the coating is to minimize radiant heat transfer between the two panes of glass, which accounts for the majority of thermal transfer through a multiple-glazing unit (excluding the spacers).

  114. Deniz Bilge | | #114

    Thanks for clarifying Robert. I was actually on the same page as you, because I thought the INNER side of the interior pane was the side facing the interior of the window, but it's really the outside. Anyway, you seem to know alot about alot, and if you don't mind, what are your thoughts about the soft/hard low e coatings which Martin mentioned? What I mean is when would one use which type and what are their disadvantages as compared to each other? I know nothing about this stuff. Thanks.

  115. Riversong | | #115


    When LowE windows first hit the market, there were noticeable differences between soft-coat and hard-coat, in terms of visible tint and performance as well as durability during manufacture. But with advances in both processes, the differences are negligible.

    What matters for the specifier or end user today is the overall performance and the glass warranty, which is typically either 10 years or 20 years, depending on the integrity of the glass seals.

    Performance depends on number of glazing panes, type of spacer and thermal break, type of edge seals, location and thickness of lowE coating(s), and the NFRC test data on the label, including U-value, SHGC (solar heat gain coefficient), VT (visible light transmission), condensation resistance and - in Canada - the (ER) energy rating score.

    Also be aware that the glazing unit will be measured by center-of-glass performance, but a window is required to be labeled according to whole window performance, which takes into account edge spacer losses, frame losses, and air leakage through the weather seals.

    Fixed windows are the most air tight. Among the operable windows, hinged windows - such as casements, awnings and hoppers - are the tightest and remain so over the life of the window, while any sliding unit - such as double or single hungs or sideways sliders (windows or doors) can not be as air tight and will loosen more with time and use.

    Finally, the quality of window sash and frame construction determines both the efficiency and the durability and ease of function. Clad windows are more durable than solid wood windows, but the miters of the aluminum, fiberglass or vinyl cladding must be well sealed. Solid vinyl windows are the least expensive but more environmentally impactful, pultruded fiberglass windows often have the best performance both because they frames are easily insulated and because they have the same coefficient of expansion as the glass (while vinyl has the greatest disparity of expansion coefficients).

    And top of the line window manufacturers offer selective glazing options, so that you can optimize performance according to orientation in the building (high SHGC on the south and low SHGC on other sides, for instance).

    Finally, the window manufacturer's or retailers warranty and service availability are critical in determining which units to buy. And price vs energy savings determines the time of payback for the extra cost. There is a wide spectrum of prices on the market.

  116. Ross Neuman | | #116

    Try Cascadia Windows & Doors I have looked at their products and they seem to be very well made. Let me know what you find out as I am also in the process of choosing windows for a house we are having designed.

  117. Dennis Kihlstadius | | #117

    HELP....designing a passive solar house in Bemidji, MN. Was going to use Serious...however now am rethinking. Is there a website for the angle of the sun so I can orientate my house to the right angle to receive full advantage of the suns rays and warmth in the winter up here. Thank you for your answers.

  118. GBA Editor
    Martin Holladay | | #118

    I think the answer to your question is simple: you need to orient your house with the long axis aligned in an east-west direction, and with about 50% of your windows on the south side of your house.

    Good free software programs to help you calculate solar angles and shading (roof overhangs) are available at Sustainable By Design.

  119. Riversong | | #119


    There is no sun in Bemidji, just cold and snow and blue oxen ;-)

    The angle you want is called true south. Get a compass and adjust for declination, or find the North Star or put a stick in the snow and check the noontime shadow and aim your house the other way.

    Finding True South

    And make sure you understand all the principles of passive solar design, including glass-to-floor area ratio and glass-to-mass ratio as well as summer shading angles.

  120. Doug | | #120

    Several homeowners have asked relatively basic questions about glazing: how much to use, what direction to face it (or the entire building), how much to spend on upgrade glass vs. insulation, and so on.
    I'd like to suggest that they contact a professional with experience in green building. Many architects, green consultants, energy modelers, and especially contractors experienced with green building will be able to help with such questions.
    Usually some computer modeling is used to optimize building design, and local climate and pricing information is needed to make choices about design, so local contractors are often an important part of the design team.
    There are some general rules of thumb that apply to much of North America, but mainly it varies a lot by climate, and each site, local market, and each building have their own issues. So, it's unlikely an internet forum can give you more than a very basic idea of what your house might need.
    Get in touch with local professionals to find the correct answers for your building.

  121. Susan | | #121

    We installed a 525 fiberglass frame Serious picture window and two casements on the NW side of our home. We have experienced severe foggy problems on the outside while our 1986 Milgard windows remain clear. We contacted the dealer and sent photos as proof; he sent stuff along to a rep but a week later not a peep.
    Needless to say, we are NOT happy with our choice right now. I feel foolish for spending a premium price for these windows. Anyone else had such a problem?

  122. GBA Editor
    Martin Holladay | | #122

    What's your climate?

    It's true that triple-glazed or quadruple-glazed windows don't leak much heat. That means that during cool or cold weather, the outside pane of the window can stay cold. On cool mornings, the outside pane can be cold enough to allow dew (condensation) to collect -- just as dew collects on grass.

    As the day warms up, the dew should evaporate.

  123. Tom L. | | #123

    I recently toured the Comfort Line plant and it knocked my socks off. I have been thru many vinyl and some fiberglass operations and nothing compares. It is clean, modern, state of the art equipment and great people. With some of the recent capital investment that they have made, the rumors about them going bankrupt or closing are just that, rumors. In my opinion as a veteran in the contruction business, they have the best products and service that I have seen.

  124. GBA Editor
    Martin Holladay | | #124

    Do you work for Comfort Line? Are you willing to share your last name?

  125. KDZ2VzDQS9 | | #125

    Seven months ago we installed Serious 925 series windows and a Serious 8’ x 8’ patio door in our new home in Northern Maryland. It has been a disaster and the worst decision/investment we made in the house we are renovating. Trying to work with Serious to make the windows and door weather tight has been Kafkaesque. They are, by turns, dismissive, disbelieving, denying, and, ultimately, disappearing. I would not buy a product from them again under any circumstance.

    We should have known we had a problem from the moment our windows arrived. To start, several of the windows were larger than the rough openings that had been specified (only by fractions of an inch, but we had to rebuild several of the openings to accommodate the oversized units). As we later learned, part of the issue is that they believe in giving the builder a very small gap between the frame and the framing. Great if you have new construction, not so great if you are working with existing openings. Oh, and don’t expect them to confirm consistent angles on windows that don’t have 90 degree angles. Their ordering program doesn’t use or display angles so if you are off on your measurements height and width measurements, they won’t catch it and neither will you. When they are building the window they won’t attempt to confirm the discrepancy.

    The frame for the large patio door was all-fiberglass construction, held together by #6 screws secured to the foam insulation. With those little tiny heads, you’d be amazed how easy it is for a #6 screw head to pull through 3/32” fiberglass when you are setting a 4’ x 8’ glass panel in it. The frame itself is only finished on three sides – the exterior wall of the frame is just the foam insulation. It looks like something you might receive on a early-era vinyl door frame. Cheap, really cheap. It has actually broken three times now, once during the initial installation, again when a workman stumbled on the threshold and pushed the base 3/16” out which tore the side frame, and finally we are seeing pieces breaking off the finger joint between the panels.

    Actually, as long as we are discussing the patio door, IT IS DESIGNED TO LEAK, yup that’s straight from Serious. It relies on weep holes to remove the water that runs down the fixed pane out of the channel holding the pane, but if the channels can’t keep up with the rain, the water collecting in the channel flows into your house. BY DESIGN. Serious does not consider this to be a problem (not a defect and “not covered by warranty”) so we’ve replaced the door with one from another company. A $10,000 mistake on our part it seems.

    Back to the windows – about a third of them leaked too. We had Serious’ representative out six times in five months. He finally ended up applying a bead of sealant all the way around each window where it meets the frame and smoothed it with his finger. So now all the windows shine along the edge where you are looking through the glass and sealant.

    If you do need a technician, this is sort of how it goes working with Serious, it is a 12-step process: (1) we observe a problem and contact their customer service person. (2) They say it is poor installation. (3) We send pictures showing proper installation and the results of our own water test isolating the source of the leak. (4) They argue that the water test isn’t valid. (5) They arrange for a formal water test. (6) We wait. (7) The fellow comes and does the test. (8) We wait. (9) They confirm that the window leaks and order a service call. (10) We wait. (11) The technician fixes the leak. (12) It rains again and another window leaks. (13) Cycle begins again and takes about a month for each cycle.

    What can we say about the experience that has been positive? The glass is terrific and insulates beautifully. The house is very comfortable and easy to heat.

    It is finally warming up here and we will get our first rain here since December. They are calling for an inch and a half tomorrow. I’m not placing bets, but I’m getting the towels ready.

  126. urUpz63m3X | | #126


    Sorry to hear about your misfortunes. However after rereading your post, there are some relevant facts I would like to point out. Btw, I am not a dealer nor sell the Serious product but know them.

    In your first paragraph you mention you are building a new house and that the windows are fraction off. On a typical install, I use anywhere between a 1/2 -3/4" so that to make up for any mistakes. If they measured it wrong or too tight then you should have refused. But you mentioned, the windows were "specified", I assume by you.

    Their ordering program doesn’t use or display angles so if you are off on your measurements height and width measurements, they won’t catch it ... if specified by you why would/should they care. The order acknowledgment that you signed off is suffice. If they made what you ordered, then why is it the programs fault. Next time order the right size.

    Then you mention "part of the issue is that they believe in giving the builder a very small gap between the frame and the framing. Great if you have new construction, not so great if you are working with existing openings".

    Did you not mention this is a new home? Very confusing to say the least...

    Then you mention the patio door. Held together by # 6 screws? Sorry if you do not know the difference between a # 10 which is used and #6, then I would say your credibility is not very reliable.

    A product that is "Designed to Leak", do you not mean weep? You never mentioned that it did leak. So why did you replace the door? My understanding from your notes is that your workman broke it. No wonder there is no warranty. A $10,000.00 for a patio door, are you sure?

    A third of the windows leaked. A heel bead is a standard fix in my opinion. You tested the window? I hope you didn't do the standard garden hose pour water on a window until it leaks test.

    James, it is very easy to blame a company for everything. Their response although slow is very thorough. The next time you post such a story you should look into the mirror because to me it looks like you made the majority of mistakes...

    Btw, after February 24th, did the windows leak? I look forward to your response.

  127. ferky | | #127

    In looking at U-Values at .30 and higher Solar heat Gain, your best value would be to look at a Vinyl window, as far as that goes a vinyl window with R-5 performance can also realize some higher Solar Heat gains for alot less then a fiberglass window. The vinyl window type I would suggest is a Casement, awning or fixed picture window

  128. rwW46tisiF | | #128

    Any info on "lift and slide" patio doors? I live on Lake Erie and oftentimes experience 20-30mph winds and several times a year winds in the 50-75mph range. These winds are referred as Alberta clippers and can be sustained for several days. I want to replace my 20yr old 8' and 5' double pane Andersons. It seems they leak air everywhere. I'm not only looking for high performance glass but superior air sealing for a sliding door. French doors will not work due to the small size patio. There is little information on the lift and slide and all the salesmen tell their product is superior to my 20yr old doors but I'd like to know if the lift and slide is superior for my application. Manufactures include Weiland, Panda, Kolbe and Marvin has one listed on their website but no one seems to know anything about it. I called the factory and their expert said it's available but they currently have no test data on the performance. It is currently being tested. The manufacturers also seem to prefer low-e double pane 1/4" glass with 1/2" spacer. They weigh a ton. The doors face the North on a recessed patio.

  129. KDZ2VzDQS9 | | #129

    Bruce, I’ll acknowledge that we did make a few mistakes. But with over $50,000 invested in 33 windows and the door, I did expect better service than we received and fewer problems than we experienced. My post was written in the spirit of caveat emptor. I like the windows; I did not enjoy my experience in working with Serious to resolve the problems we experienced with them.

    Let me clarify. It is our new home, but was a remodel of a retired Franciscan friary. Needless to say, 6.5” by 7’ cells were not what we needed and we took the structure down to its studs (retaining the footprint and chapel). We used some existing openings and created new window openings according to Serious’ dimensions. All were ‘sufficient’ according to the Serious’ recommendations. Several of the windows that arrived were larger than specified and were too tight to install. When we asked Serious about the problem they told us that they build the windows to fit tight in their openings. I’m just repeating what they said. In retrospect, we should have used ¾ instead of the ½ recommended.

    We had three large angled windows to create a glass wall in what used to be the chapel (two trapezoids and a pentagon). We didn’t ask Serious to replace the mis-measured pentagon – that was our mistake. My point is that it was never questioned and there is nothing in the ordering program to catch such mistakes (see, e.g., Pella’s ordering system), so if you are ordering from Serious, you better get those measurements right. Again, my post was written to alert readers to issues they may want to be aware of when making a major investment. As an aside, why they should care is that I would think they’d want homeowners happy with their purchase. It would be a minor bit of programming that could have caught our mistake and I’d like to see them add that capacity to their ordering system.

    With respect to the patio door, I am talking about the Frame. The door itself is a work of art (and should be, unit price $7,350.91 before installation). The frame is (was) flimsy (I've attached a picture, I think...). I stand by what I said. It does use weep holes to channel the water out of the threshold, and they could not move the rain that collected in the channel fast enough and that water leaked into the house. We experienced that below both the fixed and moving panel, but had more leaking on one side. Perhaps it was because the joint between the threshold and the jamb (on the inside of the frame from the factory) wasn’t caulked properly – after one of our water tests I watched a worm crawl out of the gap in the sealant. As an aside, Serious did not make the door frame – it was made by Inline Fiberglass, Etobicoke ON.

    And yes, a workman tripped on the threshold and it tore out through the screws securing it to the sill. Fiberglass tears easily and IMHO, aluminum would be a better choice for a threshold. If you know you are never going to abuse the threshold in any way ever, then fiberglass is probably sufficient. If you are, or anyone you invite to your house is clumsy, well, know that fiberglass thresholds are delicate.

    The windows were tested by us and by the Serious technician. They did leak (in natural rains and using standard water tests) and it took six visits to fix all of them, each arranged through Serious which took time (approximately 4 weeks between observing the leak and their representative arriving to attempt a fix). After each visit we’d assume the windows were fixed, then it’d rain, one or more windows would leak, and we’d contact Serious. None of those exchanges were pleasant. They did not want to believe it was the windows that leaked but the installation. It was the windows.

    The technician eventually ran a cap bead ( ) around every window which fixed the leaking – but is not optimal as it is visible along the edge of the glass. The technician told us he had to do the same fix to his boss’ house after his boss installed Serious windows.

    I’ve looked in the mirror many times since making this investment. It would be hard not to as it was one of the largest investments we made in this house. As you rightly observe we made some mistakes, but not all the problems we experienced were a result of those errors. As mentioned in my post, I think the glass is terrific and feel very good about the investment in energy efficient technology. I did not have a good experience working with Serious to resolve the problems we didn’t cause, and my post was written to: 1) highlight that experience for other homeowners, 2) highlight our mistakes so they can be avoided, and 3) provide homeowners with a heads-up with problems they might experience, should they choose to invest in Serious products.

  130. TEfnRYtJMB | | #130

    We had all of our windows replaced late last year with a combination of Accurate Dorwin and Loewen windows. All of the windows are triple glazed and we have higher solar heat gain on the south facing windows (which is particularly ideal for us since the tree canopy blocks out summer sun).

    We are very satisfied with our choice. I cannot say enough good things about Accurate Dorwin. The price for the Accurate Dorwin windows (with shipping) was comparable to double glazed Marvin windows, yet the quality and performance was light years better. We do not have an Accurate Dorwin dealer in Virginia, so I dealt directly with the manufacturer. The cusotmer service was the best I've ever experienced.

    I was lucky that the Loewen dealer agreed to install the Accurate Dorwin windows for us. I found that it is quite difficult to find an installer that will work with a window brand they do not sell. Even general contractors seem to have relationships with specific companies.

    The thermal performance of Accurate Dorwin and Loewen has been really good. We have large triple casement windows and the U factors are all in the low .21-.24 range. We did Loewen in our living room and family room because we wanted the Douglas Fir. The outside trim of both brands matches perfectly.

    You cannot beat these two Canadian window companies!

  131. 69ktwrVy7i | | #131

    In Portland, Oregon we have just finished testing on a new glazing combination in an affordable dual pane window that in a fixed window will provide a u-factor of .22 (R-4.55), and an SHGC of .54. We have Named the window "Solar View" and are excited to launch it... If you are looking for a great passive solar window, we've got it! Unlike Serious Windows questionable "Heat Mirror" or other out of country options.

  132. JJUDzzjZ4u | | #132

    Starting in September, Inline Fiberglass will be offering their newest Eternity Series Double Hung. Designed with beauty and performance, the Eternity will redefine how fiberglass windows are viewed. It will use the newest glass technologies and boasts a U value of 0.16 with regular triple glass. With a U value of 0.21 and a SHGC of .50 is available. The air infiltration number is a .07 CFM which is better than most fiberglass casements on the market. It will be sold as a DP 65 but reached a significantly higher number. It was designed with much slimmer sight lines, recessed hardware and a sloped sill.

  133. user-833660 | | #133

    After meetings on Passive haus, we were told and I investigated the best performance (U-value mainly), and Serious and/or Paradigm windows had the best listed performance. Paradigm double hung are listed down to .18 Uvalue. I will be using these windows for our attempt at a Passive style house (not to be certified due to high cost of certification - est. 18k$)

  134. Mike Eliason | | #134

    um, 18k for certification?!? wow. shop around.

    btw, avoid double hung windows on high performance. also, serious does not have best performance for cost - again, shop around.

  135. albertrooks | | #135

    Martin Halladay,

    This thread would benefit the last comment first arrangement.

  136. Tom_Bassett_Dilley | | #136

    Quite a thread here, just read through. Since I just went through an interesting window exercise on a Passive House project, I thought I'd share: we started the project assuming we would use Serious 925, even though their SHGC numbers could be better. It's a mid-block, south-facing lot in Chicago, and we wound up needing most of the southern wall area for windows, to get enough gain. Out of curiosity I tried Energate windows to see what the effect would be. Energate is sold through H Window in Wisconsin (no, I'm not a rep or anything, I'm an architect in Oak Park), and they're talking of manufacturing Passive House windows in that facility. The results were surprising: I was able to eliminate about four windows and nearly HALF the foam insulation around the entire perimeter of the thermal envelope. Yes, the German windows are WAY more expensive, but the tradeoff was worth it--financially it was very close, and we get windows that are better looking, better built, and they make doors with multi-point locking and great air sealing. We also were able to eliminate a steel moment frame that had been necessitated by the wall being all glass--now that we had some plywood back. So my point is--as someone else said above--get an energy rater or Passive House Consultant or someone to take a comprehensive look at the project so you can choose the best window for the project.

  137. Tom_Bassett_Dilley | | #137

    Should have mentioned the window data: Energate Solar gain glass: SHGC=0.55, U glass=0.088, U frame (1202 series) = 0.158, so full unit U values of about 0.11. Their website has testing info. Performance seems close to a lot of other German/Austrian PH windows, but distributed nearby.

  138. pkwbcLWV99 | | #138

    I am a bit late to the game, but I'll offer up my experience. My wife and I are building a passive solar home in upstate NY and have selected Thermotech Fiberglass as the window vendor... a huge mistake as it turns out. They may have a good window but they are extremely difficult to deal with. We are now in week 17 of an alleged 8-10 week lead time (we wired $15K on 6 Jul 11 as a deposit) with no end in site. When we haven't been ignored, we've been misled, misdirected and lied to. The order processing and quoting is a joke. Customer service is non-existent and their shop floor systems and procedures are farcical. Stephen Thwaites, putative managing director, (who has commented in this thread about window specs numerous times) has no control over the company, has no idea what is happening on his shop floor and may have the worst customer service "skills" of anyone I have had the misfortune to deal with. When asked a specific question about why my order wasn't getting the attention it deserved, Thwaites said, "You're assuming there is logical rational in our [shop floor] procedures.' He blames his employees for his company's problems, won't return phone calls, and won't stand behind what he says. The company culture is excuse-making and equivocating. Everyone I spoken to at Thermotech makes excuses first, before any commitment. It sickens me to think that, eventually, I will have put ~$52K in the coffers of this poor excuse for a company. Don't buy from ThermoTech. You'll regret it. (Mr. Thwaites, I challenge you to point out where I'm wrong or where I've exaggerated).

  139. GBA Editor
    Martin Holladay | | #139

    In a comment posted on this GBA page, builder Dan Kolbert wrote, "while we think the ThermoTech windows have clearly added to the house's performance, we have had ongoing warranty issues over some relatively minor problems that have soured our relationship with the company. As I've told them directly, they desperately need a service and warranty division or they will just add to their list of former fans."

    I responded with my own comment: "Thermotech Fiberglass makes great windows, but reports of slow customer service from Stephen Thwaites, the technical director of Thermotech Fiberglass, are legion.

    "Such reports are so common, in fact, that builders of superinsulated houses have a shorthand expression they use to refer to the customer service situation one experiences after contacting the company about a problem -- it's called "Thwaiting for Thermotech." (I can't take credit for coining this jewel, unfortunately.)

    "After I requested a price quote for some windows for my own house, I had to thwait for Thermotech for almost a year before I got a response.

    "Another customer who got tired of thwaiting for Thermotech was David Pill, who posted a report of his unhappy experiences on this GBA page."

  140. user-757117 | | #140

    Hm, interesting. I just received all my windows from Thermotech. They were a little slow in getting here but no customer service complaints...
    In fact, David Sargent was quite helpful during the delivery process...

    Just lucky maybe.

  141. user-1012653 | | #141

    I have had some contact with them on quoting, and actually the responses have been quick and very imformative. I can not recall who was returning my questions. I got the quote within a few days. However I am finding responses from either Inline and Fibertec are better yet, and the prices are significantly lower then the Thermotech quotes I received.

  142. pkwbcLWV99 | | #142

    @ Jesse, we got quotes quickly too. Unfortunately, the quotes were filled with errors. It took at least five iterations before they got the correct number of windows and doors. How hard is it to look at the architect's list and count up to, say, 18, and make sure your quote also has that number? It was a joke. They kept sending us "final,final,final,final, final" quotes (their words) and the quotes would be missing entire window units. Then the fun began with the specifications.

    @Lucas I am curious to know the elapsed time between placing the order and getting the windows. When did you place the order? Are you in the US or Canada? Feel free to post comments also at my blog I am on a mission to get the word out about Canada's, make that the World's most incompetent company. If I am being unfair and unbalanced, I am happy to post other people's more positive comments.

  143. user-757117 | | #143

    Without digging out the papers, I placed the order back in May and received them in September. When I ordered them, I remember asking for an August delivery...
    I believe the delay was caused by a broken pane of glass... I wasn't bothered though because I wasn't ready for them anyway.

    I am in NW Ontario (Google maps says 1482 km or 20h 28m drive.)
    I had the crates delivered to a local building supply yard (so I could use their forklift) then drove them back to my place and unloaded them manually.
    As I mentioned, David Sargent was quite helpful. He sent me good photos of the windows being crated and arranged delivery to the building centre.
    I called David once with a question about using some straps to unload the larger units and he had one of their installers call me back with some useful advice.

  144. sunstone | | #144

    We just chose to go with Innotech windows. They are building to high European standards for their glass, frames, sash, and hardware(tilt and turn windows)
    Check them out. Few are manufacturing to this standard

  145. user-1012653 | | #145

    I just received my quote from Serious on the 725 series. They were almost double the Inline triple pane option, and about 30% higher them Thermotech triple pane option.

  146. CwW47bUhgv | | #146

    Does anyone have recommendations for an acoustic window that will do a good job of blocking out the sounds of leaf blowers, lawnmowers, dogs barking, etc? I'm a conservationalist, so I would also like windows that are highly energy efficient and made of fiberglass (I do not want vinyl). I'm located in the SF Bay area.

  147. GBA Editor
    Martin Holladay | | #147

    It sounds like you want fiberglass-framed triple-glazed windows from a Canadian manufacturer. If that's what you want, the same names keep coming up: Accurate Dorwin, Inline, Thermotech Fiberglass, Duxton, and Fibertec.

  148. vkssGn7ogM | | #148

    I'm the dealer for Serious Windows in the bay area. We have 3 locations around the U.S. which sell the Serious product and find it to be a quality window at an affordable price... most recently the 5 series cost was less than a milguard double pane fiberglass unit. Serious has an STC rating of 40 on their 525 and 725 series with laminated glass on the interior. Standard series without laminated glass is an STC rating of 30. These are a low emobodied energy, high performance american made windows.
    I'd be happy to meet with you and provide a quote if you are still interested. I can be reached at [email protected]

  149. cabbagepatch | | #149

    I just read the above post and have to comment. FH Smith criticizes every single company after wasting all their time and effort. Then he/she comes here to complain about them, all of them!!! I am pretty sure I know where the problem lies...

    He mentions he planned on 10 weeks but received a quote 9 months ago from Serious?????

    Fiberglass has to be repainted...really? since when..obviously he has no clue.

    "Remember a window is not a door" ...really? everyone here did not know this...

    It is obviously that no company could satisfy this individual. I feel sorry for the window company that actually sells him/her their windows, I'm sure we'll hear about it.

  150. 4rK7DfgATE | | #150

    Dear FH Smith
    Fibertec - Sent several inquiries, they just couldn't respond ?

    We have search your name in every database and contact and lead list and could not find a trace.
    We take such issues very seriously. Selling windows is how we pay the bills.
    if you can forward me a name or date of contact, we will certainly try to get to the bottom of it.
    Good luck with your windows

  151. cabbagepatch | | #151

    Speaking of which, Fibertec apparently has bigger issues to deal with than not answering inquiries. It says they are going to run out of material and don't have a supplier .

    I wonder if the two issues are related....

  152. ZPpQvYJkFc | | #152

    My experience with finding high performing windows for our new residential project (think "semi-passivhaus") ... so far ...

    Inline - Lowest price ($16K), worst sales support from sales rep to COO, shudder to think what the rest of the process would be like, casement size is limited, so plan on awnings.

    Basically wasted almost 3 months on these guys trying to get an order ... grade F ... no wait, not even worth an F.

    Dorwin - Second lowest price ($18K), factory fire in February 2012, production delayed 4 months, took 3 weeks to tell me that ... grade C-

    If you're thinking of them, make sure they have worked through their backlog and are still a viable company ... 4 months without making windows is going to be painful.

    Thermotech - Highest price ($27K), quoting was quick but sloppy - they are the last resort just on price. Can totally see where their production issues could be coming from.

    Serious Windows - Quoted them 9 months ago when I was very first thinking about fiberglass windows and thought they were ridiculous (can't remember exact amount), but given Thermotech's price, they might be competitive now.

    Fibertec - Sent several inquiries, they just couldn't respond

    Marvin Integrity - Floor model just looked cheap, didn't bother to pursue further.


    1. Don't get hung up on the fiberglass vs vinyl (which we will probably go with) - that's like deciding on how to do something before knowing what you want exactly.

    2. You pay a premium for the very best (duh-uh), so if money is an issue make sure you are finding the sweet spot between low u-value and cost - the sales reps really know that point, so ask them.

    3. Go with someone you have a good gut feeling about - if you think they are a twit, then the whole experience is going to be marginal at best.

    4. Start earlier than you think, and then start earlier than that. I was planning on a very conservative 10 week lead time and then some cushion - it wasn't enough. It's going to be probably 5 months when it's all said and done.

    5. Make sure you understand which materials have a permanent color applied, and which ones require maintenance - vinyl vs fiberglass, etc.

    6. Remember a window is not a wall, so don't be disappointed with u-values that don't approach a converted r-value of a standard wall.

    UPDATE (April 2012)

    With the windows installed, I can update this post ...

    We ended up going with Fibertec by contacting them again and getting through (they were one of my last options, so I was probably more persistent), and the sales and ordering process was smooth. Price was very similar to Dorwin. They delivered in week 8 of their promised 8-10 week lead time - where I think other companies promise 6-8 weeks and deliver in the same amount of time. Slight frustration in the shipping process, but to be fair that was limited to just one employee and my project already being late on the windows. Once escalated, Fibertec did a good job of responding and correcting the issue.

    Windows were solid and correct - the framer of 30 years experience who installed them said they were the highest quality windows he'd worked with and it was only the second time that the windows were correctly sized and the rough in did not need adjustments in the field. The quality is something we tend to marginalize in our calculations of ROI and best bang for the buck - there's something about a window that didn't cheap out on the hardware and you can solidly close after 10 years and know the window is tight.

    Bottom line: I'd use them again. And would take all of them over a national brand like Pella or Marvin in a heartbeat - OK, maybe not Inline, but anyone else. I honestly think the money you pay is going into a quality window - instead of a national marketing campaign.

  153. user-1098342 | | #153

    Casement Window Sag

    After installing an entire house of InLine Fibreglass casement windows I noticed that many of the casement sashes were out of square. Their service manager told me that they deliberately build them this way so that they will sag into square when in use. This sounds a like a bit of a story to me. Any comments?

  154. JimNorton74 | | #154

    I'm in Maryland and I used Fibertec and have been really happy. if you're interested.

  155. user-833660 | | #155

    We purchased Serious windows 2 years ago (2012) for a new house (vinyl triple pain, krypton filled). DO NOT BUY THEM - The company went out of business and whomever bought it out, DOES NOT SUPPORT any serious window products any more. Go somewhere else.

    We are NOT happy with the windows and support for simply issues like seal failure or cracks based on manufacturers errors.

    Steve Dickerson

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