Not familiar with Fiber frame brand, but I'd look at U values and air infiltration ratings to determine how you can expect the product to perform. Okna is a top choice in that regard.

Regarding vinyl vs fiberglass: generally speaking guys that sell one will trash the other, but ultimately they each have pros and cons. It is the engineering of the product that takes advantage of the material's inherent strengths, and mitigates its weaknesses that is most important. There are great products and poor products in every material.

+1

There are some benefits to each material but it depends in large part of what the motivations and leanings of the consumer are.

At first glance one would think that this is an easy question to answer. Most insulation for your home is made up of fiberglass, so it would follow that a window frame made of fiberglass would be more energy efficient than a vinyl frame of similar quality. The reality is that the frame material itself is only a small portion of the R-Value calculation of the entire window assembly. In addition, many vinyl windows are extruded with multiple chambers for trapped air and/or are often filled with a rigid or injected foam. These processes tip the scale toward well-designed vinyl window frames, as they provide more total efficiency when compared to their fiberglass counterparts. But as you know, most of the replacement window is made of glass. The glass options and upgrades will translate to larger performance gains in efficiency as compared to the frame material. A well-made vinyl frame with an Energy Star Qualified glass pack will most often be more energy efficient than the fiberglass option. Make sure to analyze all the window data to make sure the comparison is accurate.

When it comes to the cost of fiberglass windows, they will almost universally be more expensive than their vinyl counterpart. There are, of course, contractors that charge exorbitant prices for their vinyl windows. However, even with these high priced contractors, the fiberglass option will almost always come in at a much higher price point. Homeowners should expect a price tag of approximately 1.5x the cost of a quality vinyl equivalent.⨠The consumer needs to decide if the positive attributes of fiberglass windows (aesthetics, options and construction) hold the necessary value for this price tag.

Some vinyl windows have a synthetic look and feel, which can be undesirable for homeowners. Many projects remove existing wood windows and homeowners do not want to lose the organic feel and warmth of wood.

Fiberglass window construction is closer to the look of wood, as it does not have the fusion-welded joinery that most vinyl windows employ. Although a fusion weld does have several benefits (strength of construction, elimination of fasteners and weather tightness), one cannot argue that the finished look of fiberglass is attractive and wood-like. â¨The construction materials and method of fabrication place vinyl at a slight disadvantage. â¨However, many premium vinyl windows are designed to model wood and partially bridge the aesthetic gap between fiberglass and vinyl.

Thanks for the lengthy reply windowsonwashington! Do you know more information about the brand specifically? Because of the large door (8x8) I want to make sure that I'm not overlooking the glass construction. It gets very cold AND very hot here in the midwest!

Where are you located in the MW? That will dictate which products are available.
I agree with both posters above. There are very good examples of each material, but high quality vinyl will generally return better performance at a lower price.
In looking at the fiber frame website, the performance seems pretty average. The 272 glass package is better for a Midwestern climate but at a .31 u factor, it doesn't qualify for energy star. The 366 package will, but it drops the shgc too low to the point that it is not optimized for most homes in cooler climates. The triple pane 272 looks like the only viable option. By comparison, the okna door gets a .26 u factor with a region-appropriate shgc, and a .06 air leakage rating to boot. I don't know the AL rating on the fiber frame , but since it is not given I'd imagine that there is a reason why. The entire fiber frame product line strikes me as nothing special whatsoever.

This post was edited by Karateguy on Tue, Jan 7, 14 at 18:30

Thanks Karateguy, I live in NW Indiana. I thought what you said was very insightful so I looked into the "proper" performance stats and found this pdf: http://www.efficientwindows.org/factsheets/illinois.pdf

So, it looks like the doors are pretty optimal for my climate, except the fact that it is not Energy Star approved which leads me to my next dumb question: As a brand new homeowner, what is the true advantage of installing Energy Star windows...tax breaks? (I feel really dumb asking this!)

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.

+1

They way that technology is going today, selecting a window or door product with a U-Factor north of 0.30 is neither a necessity or recommended in my opinion.

The cost of energy is going to do nothing but increase. Prepare a select your window and door schedules with that in mind.

Consider passive solar in a heating degree dominated climate and be sure to also compare air infiltration ratings as indicated by HomeSealed.

Thanks for all of your help. Still unsure of my decision mainly because lack of info on the company FiberFrame. I can't find any reviews on the product...

Forgive me for being frank, but why are you even still considering it then? Ratings that are average at best, little to no track record that you can find, and you are comparing it against what is perhaps the most energy efficient vinyl sliding door on the market right now. Furthermore, the Okna is widely recommended by professionals as an excellent product.
I could see if you are wanting to possibly throw another product or two into the mix just to feel more confident in your decision, but between these two options, the okna appears to be a no-brainer. 96 x 96 is a doable size in the Okna line.

Good question Karateguy....I was all set on OKNA until my association required the bronze exterior over cocoa exterior. Cocoa doors carry the same color on the interior while the bronze has a white interior. I am not a fan of the white interior at all.

Had a similar situation.

Had to get the Okna door ordered with the stainable and paintable interior and the the owner painted the door at that point.

That is too bad they won't allow for the Cocoa exterior...it winds up be much cheaper than the painted option.

If I were you, steer the conversation a bit with your HOA a see if you can get them to come off their position on the Bronze.

+1. Many HOA's in my area actually mandate cocoa, as it is a much better match to the old faded bronze units in the rest of the complex.

"Many HOA's in my area actually mandate cocoa, as it is a much better match to the old faded bronze units in the rest of the complex."

And in another 30 years they'll require basic tan to match the faded cocoa. : )