Double wall framing can be used to provide more space for insulation (see Figure 19). The interior stud wall should be kept apart from the exterior load-bearing stud wall to allow for continuous insulation and prevent thermal bridges. The interior and exterior wall sections can be connected with OSB or plywood spacers and erected as a single unit, or erected separately. Polyethylene film or mesh is attached to the interior stud face to contain loose fill insulation, when it is used to fill the stud cavity. Figure 20 shows an example of a wall with insulation contained in the framing space.
Source : Canada Mortgage and Housing Corporation (CMHC)