Reaching R40 wall with Common Wall? Separate Layers?

I have a 2×6 framed house with taped CDX plywood and Tyvek on the outside. I’d like to reach an r40 wall insulation, but I’d also like to skip exterior… I have a 2×6 framed house with taped CDX plywood and Tyvek on the outside. I’d like to reach an r40 wall insulation, but I’d also like to skip exterior…Read MoreGreenBuildingAdvisor