In this episode, Matt and Steve examine two elite wall assemblies—the Perfect Wall and the Larsen Truss Wall—built for maximum thermal performance and airtightness. With all insulation moved outside the structure (Perfect Wall) or suspended in a massive truss (Larsen), these walls demand equally rigorous moisture management. Learn why rainscreens and centered air barriers are essential, how to tune each wall by climate, and why these "grandaddy" wall systems influence everything we build going forward.