Double Wall Construction
High Insulation Values - No Thermal Bridging - Quiet!
Insulation is Cheap - Loosing Heat isn't.
Additional labor, Additional Framing Material, Additional Insulation will be necessary
The energy saving vastly outweighs the upfront costs of adding a second wall.
Very much like Solar PV and Geothermal, Double wall construction will pay for itself.
You will notice in this photo, the studs do not line up. This offset helps mitigate heat transference from one stud to the other (from inside to outside).
If you are in the beginning stages of drawing, Ask Your Architect about double exterior walls