To read about actual Enertia Homes, see the link.
As for this idea...
Keep the roofline running east to west.
Instead of a double envelope of solid wood, build the house with two different layers of construction material, an inner thermal-mass layer, and outer insulation layer.
Instead of
putting a foot wide air gap between the layers, use a sheet of thermally conductive metal, to which has been bonded hydronic tubing.
This tubing would run through the south and north sides of the house, including the roof, and under the floor of the lowest level of the house.
Plus, an insulated pipe would run straight down from the top of the roof.
In summer, the hydronic fluid would be pumped upwards from the bottoms of both north and south walls, down from the roof through the insulated pipe, and through a cooling system (possibly a geothermal loop), and back to the walls.
An extra thermal mass in the basement (a large hydronic fluid tank, for example) would allow some daytime heat to be stored during the day, and disposed of at night, when it's cheaper to do so.
In winter, the fluid would be pumped up the south side of the house, down the north side of the house, and southward under the house back to the south side. The basement thermal mass would be used to store daytime heat, and add it back to the house at night.