The system which is used by FANTA REAL is the bearing walls of 20 cm thickness or more, with monolithic connection between each other, the foundation and the slabs. The whole construction is monolithic and antiseismic. The walls contain the pipes and the boxes for the electrical installation and the places for the water and heating systems. The thermal insulation is placed externally. Alternatively, the insulation can be placed in the factory. The internal surfaces of the walls are ready for the painting. Buildings of 10 or more floors can be constructed with this system. Usually the construction of one floor takes 3-4 days.