Windows, windows, windows
Hello again GBA,
We are working with our builder to spec out our home that is scheduled for construction in 2020. We are in a land without codes and therefore without builders particularly familiar with codes, air-tightness, etc.
We are attempting to build a pretty good house, on a tight budget, working with a quality builder with good skills, but limited knowledge of green building concepts.
We are building with sealed Zip system and we will be testing ACH during construction. Our builder is recommending Ellison windows as that is what his distributor offers. I don’t want to go to the effort to air seal the sheathing if the windows are going to leak like crazy.
It looks like the window performance data on energystar.gov does not include air leakage. Ellison does offer a variety of windows including vinyl casements and a single hung “5700 series” that boasts “.01 cfm/ft air infiltration performance.” All of the Ellison windows, made by Atrium, seem a bit lower end in finish, which I’m fine with, if they perform well. I have not been able to find verified performance data on air infiltration for any windows.
Any advice here? I’m sure I can push for another brand if there is sufficient information to support higher performance, especially at a reasonable rate.
Very high end windows are not in the budget. We’re building air tight and well insulated, insulating the basement and slab. That along with a whole house dehumidifier with ventilation and ultra-high performance mini-splits are eating the budget for extras. We’re building at a bit of a low finish level, but striving for high performance.
Any advice would be greatly appreciated.
Cory
We’re located in zip code 38564, Tennessee.
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Replies
Air seal the sheathing regardless of the windows you end up choosing. Every little bit helps, your house is a system: if the windows are half your overall air leakage, and the sheathing goes from 50% down to 10% after air sealing, you’ve still made a 40% overall improvement in the performance of the home as a whole.
You also only really get one chance to do the exterior air sealing work. Once the siding goes up, any further air sealing work becomes MUCH more difficult on the outside. Do it right now, and you always have the option of upgrading the windows in the future.
Bill
Hi Cory,
I agree with Bill. We often have to make compromises when building, based on our budget. But just because you can't afford high-performance windows, doesn't mean you should do a lesser job air sealing, or insulating, or even including a high-performance product elsewhere.
Air sealing in particular is an affordable way to increase performance. And a really good window install is very important. One thing to consider, casement windows tend to be tighter than single- or double-hung windows. So, if you want to make a difference with a budget window, you could go with casements.
Thanks Bill and Brian,
We are definitely not planning to compromise on air sealing, etc., regardless of our window choices. I did look into casements and the breakdown is as follows:
Quoted (Ellison 150 series) double hung windows: $8500
Requested quote for vinyl casements: $14,300...yikes
After reviewing Ellison/Atrium Windows websites, it looks like their 450 series double hung windows have pretty good performance a bit under casements, but much, much better than the 150 series. Those came in at $10,176. This may be where we end up as the casements eat into the budget a bit too much.
Thanks again,
Cory
Cory,
The costs for high performance windows has really come down over the years. Our triple pane, European tilt and turn windows (Logic) were less than most Anderson lines. It may be worth exploring what is out there. Nevertheless , Casement windows are better than double hung in terms of air infiltration so you are off to a good start.
If your home is going to have air leaks then the middle of the wall (where windows are located) is the best (least worst) place to have them. Holes in your air barrier do not lose heat uniformly. For instance, a home that measures 1ACH but has air leakage at the mudsill and ceiling will lose more heat than the same house that scored 1ACH but has the leakage at the middle of the wall. This is due to the stack effect. Similarly, some materials recover more heat than others at the site of the air leakage.
Anyway, like others have said, focus on air sealing where you can- especially at the ceiling and foundation. Exterior shading (deciduous trees, ext. shades, "eyebrows",etc) can really go along way to reduce your electric bill during cooling season.
I don't see anything in your post that suggests you intend to skimp on air sealing.
If the windows are Energy Star rated I believe there is an air infiltration standard that they must meet. You could perhaps find what those standards are. Regardless, I would go with fixed, casement and/or awning windows over hung or sliders for best air infiltration performance.
I looked at the Logic website and they look interesting, but they're not in the NFRC database. Do you know if they're sold under any other name?
I believe the company name is Pinnacle.
Pinnacle is highly regarded Window retailer in Maine. They sell numerous brands including Logic. They don't manufacture the windows though. The frames are made in Germany and the glass and final assembly in PA. Not sure that they produced under any other names.
All Production for LOGIC windows is done in the US. Some material(vinyl lineals) is supplied from Germany. US Manufacturing, Sales and Service.
Are these windows (with installation) or something similar available near Boston?
Opt for fixed windows wherever you can -- you'd be surprised how much this will lower the bid. And they're definitely more airtight than any operable options.