Our home was built in 2001. We used Marvin Integrity windows throughout, except for three 12' wide patio sliders. Those are the high end Marvin. I would not buy Marvin windows again. We need to replace those sliders and I'm starting to look around. Friends of ours had a factory built home, called a Wick Home, made by a housing manufacturer in the '70's out of Mazomanie, WI. They had to replace windows and were getting all these very expensive bids because none of their windows were standard sizes. The wife is from Monroe, WI area, where there is an Amish community. They redid their windows with the Amish for a very large savings. She had to go and pick them up and take them home for 3 days, while they did the work but it was about 15,000$ cheaper than the other quotes they were getting. I'm also going to look into that. I haven't been happy with our windows. They get mold and peel paint along the inside casement frame, the big patio doors ice up in the winter along the bottom. The weatherstripping is brittle and breaks off in huge runs. The glass is cold in the winter and I don't think it reflects enough heat in the summer. We had 2 seals break. The Marvin rep came and they covered one, we are working on the other now. But we had to pay for the labor to uninstall the old one and put the new one in. It was at that point they learned that our patio fixed door was assembled backwards. Meaning the outside part of the glass was supposed to be inside. I just think all of this is enough to advise avoiding Marvin.

This is quite after-the-fact, but I can tell you that STC varies enormously by product type. If Pella is saying 27-35, then 35 would probably be for something heavy like an outswing single door with midrail and laminated glass, and 27 would be for something relatively leaky like a horizontal sliding window. Construction quality makes a huge difference as well. A luxury manufactured window like a Loewen casement starts an STC 33 with standard IG, and can get up to STC 40 with Loewen's acoustic glazing offerings. Of course, Loewen is easily double the price of Pella. Still, truly "soundproof" starts around STC 50, and only products built specifically for acoustic attenuation can meet that criteria. Also, your typical 2x4 wall only has an STC of about 33, so once your windows match the STC of your walls/roof, windows cease to be the primary source of sound infiltration.

Thanks for all the replies! Our builder uses Windsor Windows Next Dimension Classic vinyl. This is the reply that the window guy at the local lumberyard sent me when I asked for the STC: "Windsor Windows has tested the Next Dimension Classic series with laminated glass at an STC rating of 32." I'm having trouble finding specific information on the individual glass thicknesses, but the specs say this about the standard windows (not laminated): "All units include 3/4" double pane LoE 366 insulated glass as standard." We've been considering dissimilar glass as a cheaper alternative, but I'm told by the rep that the Windsor IG units are made by Cardinal, which does not offer dissimilar glass as an option. We had JELD-WEN windows in our previous house, and although they seem to get pretty bad reviews online, we didn't have any big problems with them. It seems that JELD-WEN offers dissimilar glass with an STC of 32, so perhaps that's an option. Any thoughts on this? Alternative brands? Back to the laminated glass... I'd appreciate any suggestions on economical vinyl windows (one step up from builder's grade) that can achieve an STC of 35 with laminated glass. If we decide to fork out the extra cash for laminated, we want to get the best STC possible for a typical assembly. Thank you!!

A sash kit with Dual pane and low-E would have similar performance to a triple pane unit. The STC rating would be better and much less loss of glass over an insert. Installation can be simple to comlex depending on who is installing and the condition of the existing opening . I rarely see them installed correctly by pros unless they are somewhat specialized in these, the ones they got right were because the openings and window needed no modification.