Thick wall building assemblies are tricky. For a cautionary tale see Ted Cushman, "Major Surgery for a Failing Fat Wall," Journal of Light Construction (2015). www.jlconline.com
graphic: Little, Joseph, and Benat Arregi. "Thermal Bridging Understanding its critical role in energy efficiency." Construct Ireland 6, no. 5 (2011).
www.josephlittlearchitects.com