snowqueen, I would agree with Karatemaster that the triple pane option is ideal for you if that is the product line that you choose. A .31 u factor- while okay-, coupled with an appropriate shgc is really a bare minimum. There is no tangible advantage to installing an energy star product at this point as the tax credits have expired, however they do set a baseline for choosing a product that is right for your area. Rather than looking at it as pass/fail, you really want to look at the exact ratings to determine not only how the product will actually perform, but also as a great indicator of quality. Let's look at these two products for example. The Fiberframe gets a .31 u factor with a 272 glass package. The equivalent glass package in the Okna unit gets a .26 u factor (lower is better). That is a pretty significant difference, and it speaks to the engineering, design, materials, etc. and overall quality that go into a product. The ideal product for you would be to get the U factor as low as your budget will allow, while maintaining a moderate to high (numerically) shgc. Also, don't forget about air infiltration. That is probably in the top 3 if not number 1 reason that people replace windows and patio doors, so it only makes sense to take a close look at that rating when choosing a product. I also find a direct correlation between that rating and tight manufacturing tolerances.

That's right, the installation is the thing that really matters. Best windows in the world will be junk if they aren't installed right. I've found that if you read these boards too much, you'll be too scared to do anything. What matters most is the install crew that will handle *your* job, not the one that handled someone elses in a different part of the country. The more information that you can get about those people and the work they've done, the better off you'll be. I downloaded all of the installation guides from pella.com and read them carefully, plus looked over the sample windows many times at the showroom to know what to expect. When the crew came to do the work, I kept an eye on what they were doing to make sure they didn't skip any steps and asked questions as they were working if I was confused about something. Truth is, the guys wanted to do a good job and keep the work assignments from Pella coming their way, so it wasn't a big deal. In my area, there are only two crews who install for the Pella store and lots of construction and renovation, so I'm sure they like having that Pella contract.

Owens Corning does not build a window they manufacture the fiberglas frames for Comfort Line who makes the window. Owens Corning at one time did produce a fiberglas window they were the first and it promised to be better, stronger and superior to vinyl but when we sold it we found none of this to be true and the window was a poor design. Now the Fiberon window framing OC made their window from is a totally different design than what they are producing for Comfort Line so the design may be better. Owens Corning had purchased a vinyl window manufacturer called Delsan and the Delsan window was not such a great window even when manufactured perfectly. When OC got their hands on it they only made it worse. So this is not a case of OC switching from vinyl to fiberglas itÂs just that The Owens Corning window division was a disaster and they folded it and entered into a marketing agreement with Simonton who still builds a vinyl window called Luminess branded Owens Corning. Uneeda Window

The THV uses a cellular composite material and while I am a fan, there are more proven executions of that material. Starmark is one that comes to mind and is a well vetted and reviewed product. What window was he offering as the "Fiber" frame?