It should probably be mentioned that these houses have only one or two tiny windows, walls that are up to 2m thick, two layers seperate layers of sone wall and a White domed roof, to reflect the sun's heat.

The fact that walls are made of stone is the least important factor in insulating these homes.

I'd say the roof is the most important part. For some reason we are obsessed with dark roofs, at least in the west. The dome is also innovative as it greatly reduces how much of the roof is ever perpendicular to the sun and this reduces how much uv energy is absorbed.