Doubled East and West walls:
Doubled East and West inner-shell walls (14" thick) for additional strength, energy-efficiency, and thermal mass.
This package is suitable for climates up to Hudson Bay, Canada. Or easy to air-condition in Texas. The doubled walls make it extra strong and suited for the coast and tornado alley. Go to the Legend construction sequence to see a similar package going up: http://www.enertia.com/legend-const.html