Quote Originally Posted by J08M3 View Post
My suggestion is speak with your HVAC about a load count before deciding on R30 in a 6.5" (which I guess in reality would be a 2x8 or 7.5 inch) wall or not. In my experience the difference is negligible and the HVAC requirements do not change. Why 12" spacing? Unless you do something for a thermal break the extra studs take up space where insulation could be instead. Interestingly, if you look at a house with an infrared camera you can see every stud in the wall. Better is to use 24" spacing, not only do you save on wood, but you put more insulation in the wall. Assuming the structure can be structurally sound with this technique. Hard to say without seeing the plans.

As far as basement walls being thicker, this is really just a function of structural requirements for your house.
Yeah i was just doing quick browses through Insulation. That was the highest i saw at home depot lol... I was doing 12in spacing for structural purposes, but again they just quick drawings. I will have rooms that span 20ft and depending on the truss weight i figure more support the better. But again im doing all the basic drawing design and when i feel ready to get it to an architect i will.

If its better to do 16in spacing then i will do that, i want to build a house that is really efficient in heating and cooling. This way it will be comfortable to live in, and hopefully keep its value high.

I will be building it my self, with professional help in the structural work.