wall with great thermal inertia, and with great capacity to store heat. Beyond the wall there is a air gap and a glass, so that there’s a highly heated space (through the solar radiation that reaches the glass) raising the amount of heat to be stored in the wall. This accumulated energy is afterwards radiated directly to the interior of the building through the other wall surface. So for this passive heating fully work, the glazzed part will have to be south oriented. It’s important to stress out that this system only works in the cold seasons (heating), and it must be deactivated during the warmer season, through shadding visors that would prevent solar radiation from reaching the glass, or through other shadding or external blinds, that completely cover the glass.