I've obtained quotes from six different vinyl window replacement companies for identical product and they are all within $200 of each other. Kind of disappointed as I thought there would be more variation in pricing. Is it common in the window replacement industry for companies to have such similar pricing? Not sure whether it's worth it to spend $2000 to replace two large living room windows. On a positive note, through talking to six different companies, I have changed my opinion on Low E glass.

I can share a few things about Milgard and Marvin Integrity. We are in the hot south Santa Clara County of SF Bay Area. We have Milgard and plain Marvin. The Integrity uses Marvin's Ultrex which is fibeglass. This material is very strong and is used for sailboat hull and even experimental aircraft. When well constructed, it lasts almost forever. Between vinyl (Milgard) and fiberglass (Integrity), I would pick figerglass. If you want to do "refit", do take a look at Marvin Infinity. It uses fiberglass outside and wood inside. Real nice. This was our first choice 4 years ago but its exterior color limitation forced us to use Marvin. We have two old Milgard vinyls left in our house. They are 11+ years old, I think, and they still work fine. One is a casement that faces east and is exposed to the hot summer sun from morning until noon. Some of its surround is warpng and becoming soft, likely due to the heat and sun, but still usable and may last another 5 years but no more. The other is a slider shaded by a large oak so it is like new and works fine. Unfortunately, it has no low-E coating so when temperature here gets up to 110, the glass gets really warm and the frame gets really really warm. Whatever you choose, do include low-E II (or 3) and argon gas between panes. I think Milgard is not bad at all for vinyl windows as ours still work fine. After 11+ years, Milgard may have developed some new ways to further stabilize the vinyl. Milgards are very popular in newly built monster mansion homes in our area. For "higher end" quality, Marvin Integrity and Marvin Infinity are good alternatives. Good luck!

In regards to your question and comparison of the two homes I woul dlike to make a comment. Wood is the best insulator known o man, hence the effiency of a properly built log home that being said I would venture to say the difference you felt in the 2 houses was due to installation methods were the vinyl winodws professionally installed, and possibly the wood replacement windows installed by a homeowner who thought they knew what they were doing and did not get them istalled or insulated properly. meeting rails should be reinforced to provide some rigidity because vinyl by definition is a flexible product and will bow and give over time if not reinforced. There are some vinyl companies out there that do provide a triple pane but My experience with them over time is they do cause the bottom rail to sag, A triple pane while it would be nice is not really needed. the trick is to compare the u-rating of the windows you are considering, do not go by the center glass rating, ask for the whole window rating, the lower the number the better the insulating value. A good range window should be .32 to .35 for the northeast. A Pella can get their windows o the .23 to .25 in the designer series with a triple pane but are very pricy as they offer options between the glass like shades and privacy panels. Spacers an aluminum spacer will ransfer the cold if it is unprotected by the frame so if using between the grilles in a window a dark colored foam is preferable to give a more authnetic divided light look in the edge of the windows aluminum is th emost cost efective and easiest way to go becuase the frame material of the window will insulae the aluminum. An Inert gas is still a viable insulator, if you want proof look at the U-values again you can go to http://www.nfrc.org/ and check the ratings for any company that is part of the National Fenestration Council. Windows are not a place to cut corners on price. as they can cause he largest amount of nergy loss in your house. As an aside I do not like vinyl because a) as a plastic it require petrolium for the manufacture process and with the price of oil going sky high conserve as much as you can, and b) it outgasses leaking harmful vapors into the atmosphere and your home, which is why vinyl is not recommended for greenhouses Here is a link that might be useful: national fnesstration cocil webpage

I use all three types you mentioned: aluminum clad, vinyl, and fiberglass (actually the Fibrex you mentioned is none of the above - it is a wood/vinyl composite material but not as strong as fiberglass). All three are designed to last a long time, but they have their differences. And to answer your question of "Why do these [fiberglass] windows break down faster than a vinyl one" the answer is "They don't!" I'll briefly touch upon the three types. WOOD/ALUMINUM CLAD This is actually my favorite type. Wood windows are strong, they're great insulators, they're aesthetically attractive, and the exterior can be clad with aluminum so that the only maintenance needed is washing the windows. Disadvantages include that it is usually the costliest of the three types being discussed, and it requires painting/staining on the interior side (unless you order them prefinished). Of course those could also be interpreted as advantages. Another potential disadvantage is that if the windows aren't efficient enough to handle the existing conditions, condensation could cause the wood to discolor and even rot. However, modern wood windows are preservative treated before they leave the factory, and more and more are changing to lifetime warranties on the wood. There are different qualities of wood windows, and generally speaking the better ones will last longer than the low-end ones. Some have service departments that make house calls, and some have no service departments at all. VINYL Vinyl windows sometimes last longer than wood windows, sometimes less. Like wood windows, there are varying qualities and longevities. Not only are there different qualities of weatherstrip, glass, and structural integrity, there are different qualities of the actual vinyl itself. Some will change color or turn more brittle than others (but they are all a lot better than vinyl products of 25 years ago). Wood and fiberglass window manufacturers are quick to point out how much stronger their material is compared to vinyl, which is true, but you're not buying a slab of wood or fiberglass; you're buying an entire window unit. Vinyl windows, if properly designed, will last just as long as fiberglass and wood. Fiberglass and wood windows are more impact resistant, and have less expansion/contraction, are more scratch resistant, and are stronger/stiffer than vinyl windows, but vinyl windows if properly used don't need to be as strong. How impact resistant does a window need to be? How stiff? Vinyl is just fine for it's intended purpose. I envision vinyl windows being mainly utilized in single and double openings. In new construction, where one might have 4 windows wide by 3 windows high - a wall of glass - I wouldn't use vinyl because it has a lot more flex, and that deflection under a heavy wind load could lead to air and water infiltration. It just can't meet the performance criteria of the others. But that's an extreme case. And even vinyl can come with metal reinforcements inside to make them stiffer. Aesthetically, vinyl can be some of the ugliest windows available, and it can also look quite appropriate, depending on the brand. But beauty is in the eye of the beholder . . . Vinyl window companies usually have superior warranties compared to wood and fiberglass window companies, but it's not indicative of the windows being any better or lasting longer. Here's the catch. Wood window companies usually have a warranty that applies to whomever owns the home. Vinyl companies usually have a lifetime warranty that applies to the first homeowner only. Since people usually move on average every 8 years (at least that's what it used to be; I haven't seen any stats in the last few years), that equates to an 8 year warranty. Most have a transferable warranty program, but the warranty can then be reduced from "lifetime" to perhaps 10 years, and only if you fill out a transfer of warranty form within a certain amount of time, and possibly submit a transfer/filing fee (sometimes for quite a bit of $). So some of the advantages of vinyl windows would be affordability (usually but not always), low maintenance, and very good performance (for the better brands) in medium to small openings (that's my opinion). FIBERGLASS There are not as many fiberglass windows companies out there (so far), some of the largest being Pella, Marvin, Comfortline, and Milgard. There is also the Andersen Renewal window, with its Fibrex product it is not fiberglass but instead is a wood/vinyl composite. Fiberglass windows combine some of the advantages of both wood and vinyl. They're stronger than wood or vinyl, have less deflection/flex than vinyl, are more impact resistant, do not require painting/staining, usually cost somewhere between vinyl and wood, have less expansion/contraction than the others, can not rot, and can be painted over in case you want a different color (for example on the inside of the home). Unlike vinyl windows, wood and fiberglass windows are mechanically fastened (which is neither good nor bad, that's just the way they must be made. They don't need welding and can not be welded). As for the Fibrex window from Andersen, I've heard good and bad (like I have with most brands), but have never worked with it and have not closely observed it. Seems OK to me but I don't like their negative selling approach where they slam wood and vinyl. It's backed by a respectable company (Andersen) with deep pockets. So fiberglass, vinyl, aluminum clad - take your pick. The better brands (assuming properly installed) will perform just fine in all three categories. They have different warranties, some have better service departments, some look better than others, some are better suited for some types of projects than others. It's good to look at not only warranties, options, and aesthetics, but also at performance statistics: U value, design pressure rating, solar heat gain, air infiltration, etc. Again keep in mind you're buying an entire window unit, that has many parts/pieces that are designed to work together - one should not base their decision on just looking at the frame and sash material only (aluminum clad, vinyl, fiberglass). I have Pella windows and Marvin windows in my house - two of the higher end windows around. Both have performed flawlessly and I'm very satisfied with both.