windows for a net zero home
Would love window recommendations for our net zero home. Trying to balance really efficient windows (max U .2 and min SHG .4 would be ideal).. AND want beautiful looking windows. Gone thru a number of window options.. Accurate Dorwin, Serious, Unilux..should I also consider Marvin, Anderson and Pella? Any others that I should consider? Thank you for your help!
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Hi Karen,
Martin Holladay has written plenty on this. He has an article in this month's Fine Homebuilding that you should read.
Here are a few of his blog posts...
https://www.greenbuildingadvisor.com/blogs/dept/musings/choosing-triple-glazed-windows
https://www.greenbuildingadvisor.com/blogs/dept/musings/windows-perform-better-walls
https://www.greenbuildingadvisor.com/blogs/dept/musings/passivhaus-windows
Also a good reference is Stephen Thwaites few postings on Thermotech's site. Stephen's pretty knowledgeable about windows.
http://www.thermotechfiberglass.com/news.htm
I am partial to Thermotech because that's what I have in my house. It is a fibreglass frame that optionally can have a maple (oak?) veneer on the interior side if you want wood grain. I'm impressed with them.
I am pretty certain that Marvin, Anderson and Pella won't have a window that will work for you. That said everything is dependent on your local climate and your design. And you won't know whether the windows you choose will get you to net zero unless you put the house design through a good energy modelling program like PHPP.
Cheers,
Andrew
I worked on a Passivhaus project that used the Optiwin Alu2Wood window.
http://www.optiwin-usa.com/
They can meet your specs easily and they are comparable in cost to Marvin triple pane (depending on exchange rates).
They are beautiful wood sash tilt and turn windows manufactured in Germany among a network of smaller craftsperson orientated operations. You will need to be prepared for a 3-4 month lead time however.
Also depending on what you are familiar with you should study the relevant window details to make sure you are taking full advantage of air tight and thermal bridge free installation.
"Net-Zero" is a meaningless term, since it could include an energy-wasteful design that includes a mega-generation system.
I assume you mean you're building a minimal-energy home, in which case the "best" window is largely dependent on your climate zone and the solar availability at your building site (assuming that the design is taking advantage of passive solar before using active generation systems).
Karen, have been searching for affordable high performance windows for my energy efficient remodel. I eventually opted for Uniframe by Great Lakes Windows. Their picture, casement and awning styles have U-values below 0.2 and very low air infiltration rates. Plus, they are actually affordable!