I'm new to this forum, but I've been looking for an answer to a question we have about insulation. We're about to build a new home, and while we can't afford all the "pure" green ideas out there, we want to at least make it as well-insulated as possible without breaking the bank.
So here's the question: the plans at the moment call for 6" studwalls, with 2" rigid foam insulation on the exterior, with the joints taped to eliminate thermal breaks. Our contractor, whom we highly respect, says there's significant cost to this, because of the labor costs involved in the multiple trips around the building required to accomplish it (sheathing, wrapping, rigid foam, taping, firring, siding).
Since the principal value of the rigid foam and taping (at least as I understand it) is eliminating the thermal breaks created by the studs, we've come up with an idea that sounds intriguing, but no one can tell us if it would really work. The idea is this: using 2x6 headers and sills, use 2x4 studs 12" on center but alternating sides, so that half the studs would be to the exterior and half to the interior. This would give you 2' on center nailing surfaces both on the interior and the exterior, but eliminate most of the thermal breaks, creating a sort of S-pattern to the insulation if you look at it in horizontal section. It also actually reduces the amount of wood you use (at least in actual volume). It would be a little trickier to frame, but nothing insurmountable, and it eliminates the thermal breaks, which would eliminate (or at least significantly reduce) the need for the rigid foam and several of the the trips around the house.
Is this crazy or innovative? And if it's innovative, why hasn't someone smarter about construction than me thought of it before?