The least expensive low energy buildingblock structure !

This 350 mm thick wall has 0.159 W/m2K and as such so called matalenergia ( low energy ) wall !



Slight disadvantage in this is that 250 mm wall as such uses almost as much energy as log house wall ( 0.339 W/m2K ) and it needs the insulation after the first heating season + the windows will be potruding from the wall and thus not very good looking during the first year as long as the walls are not insulated from outside.

Good thing about 250 mm thick light concrete wall is that it dries very fast and could actually be insulated the very same summer as the walls are being erected.

Also 375 mm wall could be insulated the same year if building starts early in the same year ( march/may ).