Wall insulation techniques - 2x6 vs double 2x4 vs foamboard sheathing
This home building process really taxes the ol' noggin, so many different options!!
I'm building a very small scale home (120sq ft) and would like it to be well insulated with no thermal bridging. I'm aware of several options that would insulate the walls well: so called "advanced framing" with 2x6s on 24" centers, two 2x4 walls with a space in between, 2x4 staggered studs on a 2x6 plate or a 2x4 wall with foam board attached to the outside
I had initially decided on staggered stud but am now second guessing and wondering if I shouldn't just do 1" foam board (plus cellulose insulated stud bays)
Pros of the foam board approach: Very good insulation, less lumber than other approaches, no need for housewrap (saves some money)
My only concerns with the foam board are attaching windows and doors; the thicker sheathing seems like it would require special windows/finagling.
I would have 1/2" plywood, 1" foam then mesh and stucco
Any help in this decision making process would be immensely appreciated