Spray foam sealed attic 1.5 story house question

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Spray foam sealed attic 1.5 story house question

My wife and I are planning to build a 1.5 story home. By this I mean that we will have a game room, office, and a planned future moive room upstairs in the "attic" space. The office will protrude out of the 1 story roofline as a former, but other than that, everything is contained within the 1 story 8/12 roofline. The rooms are centered and sized such that there are no hip walls, and all have an 8 ft beam.

My question is: if we spray foam insulate this house and use sealed attic techniques, does this eliminate the need to insulate the walls of the "second" floor rooms? The way I see it, they are all already contained within the fully sealed and insulated envelope of the house and therefore the walls of those finished attic rooms should be no different than the cieling of a 1 story home. And that, as I understand it, is left uninsulated if the rood decking is what is insulated in a sealed attic home. I suppose there may be some extra heating upstairs from stack effect but this is in any two story house.

My hope is that I can essentially skip the insulation process for the upstairs walls and save the costs. In this case, the insulation costs should be the same whether those rooms were up there or not.

Can anyone advise on whether this is a good idea or fundamentally flawed? Has anyonne done this? Thanks!

Gohmert Residence_A4_110412.pdf286.12 KB
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Asked by Dustin Gohmert
Posted Sat, 11/10/2012 - 16:08
Edited Sat, 11/10/2012 - 16:13