Wood used in framing has a small r value because of the air. The timber on the exterior prevents all the energy transfer. The loss of r value can be off set wi

Wood used in framing has a small r value because of the air. The timber on the exterior prevents all the energy transfer. The loss of r value can be off set with two 2x4 frames. As strong as a 2x6 wall and about the same price. Added benefit is air gaps.