Conduction
As the Onawa population already discovered, the surface/volume ratio deeply affects the thermal dispersion of a closed ambient; in a similar way, in the northern side of the world, the Inuit discovered that the semi-spherical shape was the best approximation to the s/v ratio perfection. Hence, in such a climate, it is important to lower the dispersion surface, this condition can be satisfied by also creating a building that is in part buried (fig.1 vs fig.2), which reduces the area that loses heat to the external air (soil has a constant temperature of 12°C, while air can reach -10°C).
The technological improvement in buildings has allowed to consider the effect of thermal bridges (fig.3) and prevent their presence.