Perhaps not, but as we know we can use the best material in the world and if not engineered properly or quality control standards adhered to you can a product that is subpar in performance. Have you had any experience with the higher quality vinyl windows, ones that have higher PG ratings, better air infiltration ratings better U-Value ratings? All these would have far better numbers than the Marvin unless you want to use there numbers that are using tests that are irrelevant .

I am not someone who posts reviews on the internet, particularly negative feedback. But, given how much false information and untrue ads are out there for the “high quality” of Marvin, I have decided to do what is right and post my experience with them on a few websites, such as Houzz. Four months after we placed the order, Marvin delivered the windows. Some of the windows had obviously been dropped before delivery. Scratches on the outer frames and bumps on the inner side clearly showed that. We noted the issues as they were unloading the windows and took pictures on their truck. They may claim that they have good quality windows, but when they are dropped it basically does not matter anymore as the structure of the windows is certainly compromised. As for customer service, the windows were delivered in April and we notified the vendor and Marvin of the issues immediately as they were still unloading the windows. Four months later, we are still nowhere and nothing has been fixed. They just delivered one wrong frame for a window which we never asked for a fix and they are not even coming to remove it from my property. No word on when they are going to fix the windows. Total mess on their side and non-existing post-sale support. === Update of October 2021 I got an email from Marvin regional manager today; and it's the middle of OCTOBER -- 6 months after installation date. They plan to replace the broken sashes -- get ready -- in JANUARY NEXT YEAR. This joke is not even funny. Stay away from this company at all cost. They couldn't care less about you once they have your money. Go with anyone but Marvin. I mean, the worst thing that can happen is that you get broken windows and they never fix it --- well, that's Marvin.

Hello! Update: WIndows/Doors Choice is now between: (A) Milgard thermally improved A250 aluminum 16 windows - mixed casements and sliders, 3 sliding patio doors 96" X 82" and 1 sliding patio door 72" X 82". Quote for those installed is $44,000. or B) Milgard Ultra C650 fiberglass 16 windows - mixed casements and sliders, same size and number doors. Quote for those installed is $65,800. My understanding is choice (A) the fiberglass windows and doors will comply with Title 24 for my Bay Area home. But as they are $20K more, with fatter sightlines, we are considering hiring a company to provide us with "as built drawings" (floor plans) for our home, and we then hire a Title 24 consultant. My home will then be evaluated for energy efficiency and given a number. By undertaking other energy saving measures (new furnace, R38 insulation instead of more basic, and other measures I know not of, but hope to learn) we can make up the difference for the U value of 0.38 for Milgard thermally improved aluminum, which just misses the 0.30 of Title 24. Milgard standard aluminum has a U value 0.45. Has anyone else gone the energy survey route with a good result? Are these facts correct? Are these quotes fair for the Bay Area? This second contractor is also installing Hardie Board as I noted in my OP. (The first contractor failed to get back to us in time, and so here we are months later. Marvin still not an option, as he's not a certified installer and we'd have to buy them outright.) We are trying to move fast to avoid yet another price increase. Thanks. Should I start a new thread as Sierra Pacific is no longer in the running?

Thanks, @millworkman. I also thought the shims were the issue. However, I only used shims for two reasons: 1) to ensure the windows were plumb, level and square, and 2) to ensure there was no daylight at the side of the sashes when looking at them from the inside. My understanding is that we have to ensure both #1 and #2 -- it would be unacceptable to not have the window plumb/level/square, or leave the sashes so "loose" that one could see daylight. We used black plastic stackable 1/16" shims around the per pre-drilled screw holes, and it was mostly only 1 to 2 shims per hole -- in rare occasions, three shims, and some of the holes needed zero shims. The reason we actually used fewer shims than expected is that the windows were measured very precisely. Marvin Elevate frames are 3/8 shorter than the opening width, or 3/16 in each side, less than the usual 1/4 per side. But I did follow the instructions, and measured precisely -- perhaps too precisely -- and let Marvin deduct what needed to be deducted. 1) I will use the dry lubricant. It can only help. Any views on that? 2) We have not installed the trim yet. Should we remove some of the shims, risking that some windows would no longer be plumb/level, or risking some daylight from the inside? Also, we put some minimally expanding foam for windows and backer rod, so removing shims might mess up the foam at this point... 3) Instead of removing some shims, should we slightly loosen some of the screws? 3) I was actually at a Home Depot earlier today and tried some of the windows they have on display. There were clearly easier to operate. Should I assume that any window that is a floor sample, and not installed/shimmed in an actual construction site, would always be easier to operate? I'm just trying to get some perspective...