Double-Stud Wall

Prompt

What is the best way to superinsulate a wall?

Findings

As builder Ben Bogie demonstrates above, the double-stud wall is simple: it is traditional framing that receives an additional non-bearing stud wall at the interior. The space in-between this interior stud wall and the exterior wall is stuffed with (carbon sequestering) dense-pack cellulose insulation, and width can be varied to achieve almost any R-value. When we superinsulate a wall, we should be concerned about how that affects moisture. It is critical to properly air seal double-stud walls in order to ensure moisture does not condense on the back side of the cold sheathing in winter. As such, we detail this assembly carefully and only use it in certain climates.