Aluminum vs. Vinyl windows

[Credaholic]

Any Mustachian builders out there care to weigh in on the current debate going on in my house? We're building a modern style home, and hubby wants to use thermally broken aluminum windows. They look great (have the low site-line profile he wants for our home's aesthetic) and being thermally broken means they're actually energy efficient. It also means they are mega expensive. He's looking at Fleetwood or Reynaers. We also have a quote on Milgard's Thermally IMPROVED windows which are not as energy efficient but are about 30% less expensive. If we were to go with vinyl windows we'd also be about 30% less expensive but have higher energy ratings while ruining my husband's day with their hideousness.

I agree the aluminum windows are more attractive. They're also more recyclable in the future. However, I've read that the metal on metal construction can mean more maintenance and difficulty opening them. There can also be condensation issues. Vinyl has all that stuff dialed in, and I personally think that the look is simply not bad enough to outweigh the cost savings.

Does anyone have thermally improved or broken aluminum windows and care to share their experience? Anyone out there with modern/mid-century modern aesthetic and making vinyl windows work with the look?

[AaronMN]

Where are you located?  This will greatly help with the decision making process. 

I would stay clear of vinyl.  I would also not recommend going with all aluminum, even if thermally broken. I would much prefer someone to go with an upper level fiberglass or wood/wood aluminum window. 

Have you decided on which types of window you will be installing?

[Credaholic]

Should have said, we're in Seattle. Moderate climate, but very high energy standards. It's actually possible that the Milgard thermally improved won't have a high enough rating to pass code. We'll have casement, awning, and of course some inoperable windows. I actually just was looking at Milgard's fiberglass Ultra series. Will fiberglass be comparable in price to vinyl? I was thinking of requesting a bid for this line next week.

[AaronMN]

They will be higher priced than vinyl.  Are you settled on Milgard?  Quote, quote, quote, quote, then ask for a re-quote. 

Great choice on casement and awning, I can see you have done a great job with your research so far.

Do you have mostly singles, or do you also have assemblies?  Any SDL's or casings?  Have you settled on which glass coatings you will need?  Dual pane with argon?  What are the code requirements in your area?

[Credaholic]

Not set on Milgard, but they're the cheapest possible aluminum option so I've been searching through their other options. Fleetwood and Reynaers are obviously much more expensive. We'd be going with the most low profile casing available. Yes, dual pane with aragon. If I understand correctly we have some assemblies but mainly singles. I'm attaching a pic of Seattle's U-Factor req.

My husband is a contractor so knows what he is doing and is getting discounted rates (and using his difficult wife to get quotes down even further ;) but if it were up to him he'd convince me that the Reynaers are the only possible option and we have to go with them, so I'm trying to make sure I get both sides of the story. When I googled vinyl vs. aluminum I started to get really worried that we'd be spending too much money AND getting a product with a lot of drawbacks I'd be unhappy with.

[AaronMN]

I'm not quite sure I understand that image.  I am used to seeing numbers such as:

http://www.nfrc.org/windowratings/Energy-ratings.html

You can play around with something like this to see which glass options give you the U Factor or SHGC you specifically need on the Energy Data tab:

http://www.marvin.com/windows/wood-casement-windows/technical-resources/

Edit: looking closer, I'm surprised to see the U factors so high on your image.  You will have no problem meeting that with any halfway decent window.  However, if you are truly concerned with energy conservation, you would be looking closer to the .30 range.