From the 3D printing company: https://www.alquist3d.com/faqs https://www.alquist3d.com/faqs [..] The house contains a thermal break at the exterior walls, mean

From the 3D printing company: https://www.alquist3d.com/faqs https://www.alquist3d.com/faqs [..] The house contains a thermal break at the exterior walls, meaning that the house acts similar to a cooler, keeping cold air out in the winter and warm air out in the Summer. As a result, the house is a “tight” envelope and requires additional air exchanges, cycling fresh air into the home frequently through an energy recovery ventilator (ERV). The current r-value of the walls is estimated at 21.5.[..] For Vancouver.. an r60 wall is required as of this year. Virginia at r21.5 seems not so thermally efficient. Also: [..] We estimate, for the Richmond home, annual energy costs to be about $1,100 without solar.[..] That seems a tad unrealistic.