Energy-efficient walls with conventional building techniques
IrishGuyJohn
| Posted in Energy Efficiency and Durability on
I’m building a house in Zone 4A. The builders here are all very conventional. They are comfortable with 2 x 6 construction [or 2 x 4].
Can a staggered 2 x 4 wall be built [to minimize thermo bridging] on a standard poured concrete foundation? Does staggering require significant additional materials and/or labor?
Would a 2 x 6 standard wall with a 1” exterior sheet insulation be better than a 2 x 4 staggered wall?
Given the constraints of traditional building techniques available, what is the best way to go?
Thanks
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Replies
Using conventional building techniques, the simplest thing to do is to frame with 2x6s 24" OC (double top plate, not advanced framing), fill bays with cellulose (though fiberglass is only a small loss) and use Huber's ZIP R sheathing system or similar product. Hardly any new techniques involved, just some tape. Gets you up to R12 on the outside, and a good air barrier. That is what builders have started doing in my area to meet code. Note that R 4.5 is minimum for ext. sheathing in you climate zone, if I recall correctly.
That's probably the best bet. Nothing to scare off contractors and you still end up with a well performing wall.
One extra note: It is a good idea to include a blower door test in your contract, and require your home achieve a certain result. This will incentivize your builder to get the air sealing details right, and not skimp on it.