Construction Guide to Next Generation High Performance Walls in Climate Zones 3-5 - Part 2: 2x4 Walls

Part 2 of this Construction Guide to High-Performance Walls in Climate Zones 3-5 provides straightforward and cost-effective strategies to construct durable, energy-efficient walls. It addresses walls constructed with 2x4 wood frame studs, wood structural panel (WSP) sheathing as wall bracing and added backing for foam sheathing, a layer of rigid foam sheathing insulation up to 1.5 inches thick over the WSP, and a cladding system installed over the foam sheathing in low-rise residential buildings up to three stories high. Walls with 2x6 framing are addressed in Part 1 of the Guide.

The addition of exterior insulation to standard 2x4 framing enables an easy transition from conventional 2x4 wall construction to a much more energy-efficient wall system that is effective at minimizing thermal bridging from framing members. Only minimal changes to detailing and cladding attachments are needed for the system detailed in this Guide.